Alpha & Delta D6 - Reviews
Pros: Clarity, balanced dynamic sound, addictive and well textured mids, circular around your head soundstage, layering, mature tuning, bass extension, 2 soundsignature, incredible construction, accessories, price value
Cons: some cable microphonic (can be solve wearing over ear)


The magnificent looking Alpha & Delta D6 intrigue me since lot of time, especially because of the marvelous 8 cores cable it have but as well because of sound engineering hide in the housing. I would have like to know exact compenent of 10mm drivers but this is still top secret, but the dual air chamber technology still is something quite rare in IEM world at this price range. Such a serious approach for an acessible price make the budget audiophile in me became obsess to try these and now the day is come and even with long fermented expectation that became surely overly utopic, i’m far from being disapointed by the end result, quite the opposite in fact.


After reading conflictual reviews and feedback about the D6 -some praising them other being very disapointed by bass performance- I decide to contact directly Alpha & Delta to offer them to write a review in exchange of a discount. In all independance, I choose this model and the AD01 and in no way the nice staffs ask me to compromise my opinion. To stay independant, you have to make your own choice and do not receive dicey reviews sample to promote them. I have no sugar dady above me to tell me what to do and it will stay like this forever.



Unboxing experience is very pleasant and generous, we have multiple eartips including silicone and foams tips. We have a ear hook and a cable clip. As well, an extra nice leather case. I don,t think we can ask more, i feel spoiled here.

P1290546.JPG P1290545.JPG

Construction surpass my expectation even if I see numerous excellent pictures (do reviewers have fancy professional photograph team?), its just supremely amazing for the price and no details was forget, having this type of quality for 100$ is extremely rare because it isn’t crafted just to be a looker, ALL compenents are really high grade! Housing is thick polished metal with 2 vented hole, L jack have a tension release spring to avoid pulling damage, housing cableconnecting have as well rubber protection...well, if I became intensely severe...I will begin to find problem with nozzle mesh I guess wich is not metal but this as well is surely thinked for proper minimal sound filtering. And. I. Don’t. Even.Talk. About this incredible 8 cores SPC cable!!!!!!!!!!! I will tell you a secret : I like to sensuously touch it, like, it give me goosebump and have a stress releive effect on me while listening in the subway etc....yeah, its so sexy it give me an hard on, no wonder I have no girlfriend! Who need one with such a hottie cable! (Okay shut up Nymphono, its embarassing)
(Above is comparaison of A&D 8cores SPC vs some random 4cores SPC cable)

Design is well thinked for sound, durability etc, perhaps a little less for comfort and practicality for 2 reasons : One being that the housing is quite big and long but at least its not heavy, but still, it can perhaps be problematic for small ear or when cable is pull it tend to easily fall. Two is that this oh-so-seductive cable can cause microphonic quite easily, argh why!? But there an easy way to fix BOTH issues : wear it over ear and voila, no microphonic, no falling du to cable pulling.



Overall impressions :
The D6 are something special, and to be honnest, it wasn’t a big WOW first listen first love story, because this isn’t thinked to be over colored in sound rendering and easily entertain your ears and make smile the little immature audio kid in you with a V shape sound and over pushed microdetails. Nope, this is rather serious earphones so it take me a big FIVE big minutes to became utterly passionate by this sumptuously musical master class. I cannot call this brain burn in but more a new respectfull way to concentrate on music and enjoy it with sacred contemplation. The D6 are very accurate and have excellent impact-decay rendering as well as an immersive around your head soundstage with good deep, all this with incredible level of clarity and natural texture that help achieve a superbly realist imaging. Highs are sharp without sibilance and offer good brilliance that do not echo too much as some would be afraid with such a double chamber big housing, here we have serious sound engineering that merit admirative applause because Alpha & Delta have create an affordable audiophile IEM that will stand test of time….wich perhaps explain there 3 years guarantee?

SOUNDSTAGE is like being in an excellent acoustic recording room, not an immense hall, its circular and realist and have excellent deep and above average height. This is clean and the air can flow, but will not expend to the point of saturation.

SOUNDSIGNATURE is difficult to describe because its just slightly colored in all frequencies mids sections in a very subtle way, we have a little bump in mid bass, little bump in mid vocal, and another bump in the highs, I think we can class them in neutral-analytical with ultra extended treble category without being too flat or boring. Even if slightly bright, its not grainy or hissy at all, just sparkly, so I don,t think people that are treble sensitive should be afraid of the D6.

AMPING isn’t a must, but D6 aren’t ultra sensitive IEM either so they perform very good with my Ibasso DX90, Xduoo X20 or DAC-AMP Xduoo XD-05, and will not achieve full potential with Xduoo X3 or my LG G6 (but phone are for audio phonies aren’t they?).


ABOUT EAR TIPS, now, this is something EXTREMELY important and as stated by Twister6 headfier, it can be use to change soundsignature in a more V shaped way and a good one! In fact, when I listen to beat driven electro, i just push my KZ starline eartips and voilà! I can enjoy a more impactfull and bodied bass response with a more fowards energic sound presentation wich is not far from sounding like another IEM. I don’t know if Alpha & Delta think about this aspect creating their D6 because its not explain in there product description, but one thing sure, other iem company should take note of this design approach wich is better than changeable nozzle filter IMO and way more easy to tweak. We often see audiophile playing with vented hole and covering it for extra bass but the fact the venting hole is at the base of nozzle is a game changer in term of easy tweak, for me, its pure genius and a big plus for versatility in soundsignature. Most of time I do not cover venting hole because I prefer a more vast around your head soundstage, but for electro its a must.

(to note, follow sound impressions are with eartips wear the normal way)

(this is the official D6 frequencies response graphic)

BASS is realist and extend deep without lot of rumble but a good amount of punch and lower end extension. It is an agile tigh type of bass that can be very good for rock as well as jazz, because it is able to give fast well textured punch as well as having great extension for acoustic bass note that will neither sound dry or too thick. Listening last Jacob Bro ‘’Returning’’ jazz quartet album is pure delight, it is really as being in the middle of musician and Thomas Morgan upright bass line are to die for, in fact, they kind of steal the show even if percussion, saxo and guitar sound superb too. So, yeah, D6 have a special relationship with acoustic music but at the same time are very versatile. We can feel the fingers of bass player pulling the string and making note impact that extend in vast soundstage naturally, this album rarely or never shine so beautifully than with the D6 to be honnest.

MIDS too are extremely impressive and will became magical with some instruments like violin or saxophone, piano strangely is not as good but still sound above average and very clear. The mids are greatly textured and have nice transparency, wich is how it should be in reality. Taking same ‘,Returning’’ album the saxophone is in front row when the musician is in its solo and will go background when needed, sound expend widely in an airy way, have good textured that do not sound saturated at all, instruments placement around the sax is ultra-realist too. No, even if the frequencies response graph kind of show a big bump in mids, it never feel too fowards or agressive, but it sure aren’t recessed at all, vocal even if greatly textured too will not sound too thick and are just slightly bright with extra presence and intimate presentation that isn’t the widest but shine in the middle of soundstage. Just very rarely we will have some upper mids peak that can give to much resolution to voice microdetails, but some will find this fascinating as it do not create sibilance whatsoever.

HIGHS are very sparkly and nicely sharpened up, the treble extension of D6 is the star of the show and masterfully tweaked for a sub-100$ iem, it remind me of topology drivers find in TOTL earphones like the Hifiman RE-800 but comparatively to the 800 the soundstage is bigger and feel less fowards (yep, I sincerly prefer the 100$ D6 over the 600$ RE-800). Percussion, whatever the number or type used, sound marvellous with controled brilliance and ultimate clarity as well as spot on placement that never feel artificial or too bright. Better is your recording quality more impressive will be the result, well mastered complex eletronic full of sound information will be jaw dropping, as I discover with artist such as Ametsub, Shuta Hasunuma, Objekt or ADR, making this type of bassy but details crowded music incredibly enjoyable. Everytime I hear new details from an IEM I think there nothing more but yeah, D6 proof the contrary and make me say the cliché sentence : I hear new details I never heard before (wich is even more joyfully disturbing with Ibasso DX90). You know, when you listen to your music and got strangely absorb to the point of feel being litteraly swallowed by your earphones or feeling as if you have some type of astral travel experience? D6 do this to me lot of time, its hard to explain, but its a precious mystical experience that i’m sure audiophile crave for.



VS ALPHA & DELTA AD01 (100$) :

Soundstage of AD01 is wider and slightly taller but not as deep and more frontal than D6. AD01 is way more V shape and bassy, not too say slightly boomy, impact in sub region is hardcore compared to the clearer better extended D6 bass with tigher punch that feel way more realist and have better details without drowning the mids as the AD01 do to some extend. Mids of AD01 have less details and are more shouty and can have bass rumble covering it when a track is too bassy, D6 is in another level with more details and better presence as well as more realist separation from rest of music instrument. Treble of D6 is more extended giving more details and texture but feel less harsh than AD01 wich lack finess and microdetails and is on the overall warm side even if not truely bad in this department (problem being the mids). Construction of D6 is from another level even if do not have detachable cable. Price value is better with D6 wich can compete with higher priced IEM where the AD01 feel slightly too pricy with today budget iem competition.

VS TIN AUDIO T2 (50$) :

Oh, no! The big budget killer come in the ring watch out! Should we be afraid? Nope.

D6 bass is way more realist, dig deeper in a linear way, have more texture as well and more punch wich lack in T2 and make electronic sound quite strange and unbalanced. Still, the very capable T2 have thicker sub and will give more body to cello and make it better sounding. Another time D6 is slightly more intimate with soundstage but have more deep and around your head feel where the T2 is wider and airier but less clear too. Mids of the T2 are wider and have more body but can be a little bright too in upper mids and create very rare sibilance with female vocal where the D6 is more details, clear and transparent without harsh peak. Treble is quite similar with both as they extend alot, but the D6 is better controled and will give a little more micro details and sparkle. About layering and imaging, both are very capable but T2 have more air between instrument, still, as the D6 have more clarity it will deal better with more complex track where the T2 can have too much mixed up decay. Construction of D6 is nicer with its 8 cores SPC cable but its not detachable….even if the 4 cores SPC cable include with T2 turn green after a week. All in all, D6 sound more realist, clear and controled where the T2 sound wider, more mid centric and airier.

VS NiceHCK M6 (110$) :

So now, that’s something very different in term of drivers implementation : the M6 have a dual dynamic+4balanced while the D6 having only one small 10mm dynamic drivers….could it be really a fair fight? Well, yes, because of incredible D6 dynamic driver! But, still, its like making a battle between one incredible fighter against 5 good ones and I will not lie telling its kind of a bizarre fight. M6 is warmer and more V shape, but it could be its force too here. The D6 linear bass feel less excapting but especially less impactfull and physically separated from rest of sound spectrum, the M6 layering and transient response being excellent, bass have more body and thicness without drowning anything in its passage while the D6 feel thin with more texture and details that are harder to hear because it’s low end stay in back stage. Mids in another hand are more present and detailed with D6 and even if brighter than M6 do not have this strange mix of warmnest plus hint of upper range hissing that can occur with M6, vocal are more enjoyable with D6 even if treble is more present. The M6 aren’t really recessed in mid range, just not as resolved as the D6 but the separation is better with M6 and have more space between instrument. Treble is more extended with D6 and highs have more sparkle as well, we can find micro details more easily but M6 have all of them too in the well separated layers of sound present in its vast soundstage. For solo instrument I prefer D6 as it feel it can deal better with faster instrument like Bach solo violin sonata, but M6 have excellent transient response, just less grip and presence in overall technicity of specific intrument. All in all, M6 offer a richer sound experience for tracks with lot of instrument, bassy music or pop while D6 is better for singersongwriter, folk and solo or duo instrumental, both excell in there style and cannot really find a winner here.



I sincerly applause Alpha & Delta audio engineer as well as construction designer here because this type of serious sounding and TOTL looking earphones a rarely seen in 100$ price range and even in sub-200$ one. A&D make a long way in sound maturity from the more tactless AD01 and I can't imagine what they hide for the futur, but have heard a new universal micro drivers iem is on the go. The Alpha & Delta D6 is an extremely well balanced sounding earphones where nothing feel too pushing fowards, it have sumptuous texture in all range and great imaging that do not feel forced or artificial, its really audiophile target but without compromising too much on bass performance and even make it incredible for acoustic bass as well as lower extension. The fact we can tweak soundsignature a little pushing eartips above vented hole is a big plus that make them even more versatile. If you searching for a budget earphones with unbeatable construction and a neutral approach that do as well for critical listener than average music lover with multiple music genre taste, the D6 is an exceptional achievment that will offer you a clear, vivid well layered sound experience that do not forget about musicality importance. If it wasn't for microphonic, I would have give the D6 a 5 stars, but a 100$ I need to be ultra severe even if sound is extremely near to perfection here.
Pros: Near neutral and responsive bass, clear and detailed mids, spacious and natural highs, good staging and layering, solid build, excellent 8-core cable, amazing accessories, 3 year warranty.
Cons: Non replaceable cable, visual indicator of L and R not easily seen (a Blue/Red color band anywhere near the strain relief and shell could have fixed that)

Alpha & Delta is an audio company that started producing their first IEM (The AD01) back in May, 2015, steadily building up their products till their most recent release with the D6 in November, 2017. "Based in Singapore, Alpha & Delta is a work of love by a group of audiophiles with experience in the earphones retail industry. Being avid audiophiles ourselves, we understand what audiophiles want and we strive to produce quality products at an affordable price." - a direct quote from their website and it shows their dedication to that vision with the D6, having 2 goals of excellent sound and durability for it.

I would like to thank Alpha & Delta for providing me with a review sample in exchange for my honest and unbiased review. You can buy the Alpha & Delta D6 at Lend Me UR ears or locally if your retailer has them in stock.

Driver unit: 10mm dynamic driver
Impedance: 16 ohm
Rated power: 1mW
Frequency Response: 10 Hz- 40 Khz
Speaker Sensitivity: 105 +/- db/ mW
Cord Length: 1.2m silver plated copper cable (each core contains 22X 0.05 silver plated copper wires)
Plug: 3.5 mm

The 16Ω and 105db sensitivity of the D6 does translate into real world good volume and ease of driveability for even the most modest of sources. Aside from the standard specs, there are two technologies of note with the D6 that makes it a very interesting IEM, "The dual chamber acoustic design redirects reflected sound waves into a uniquely designed second chamber which absorbs these sound waves. This reduces distortion and improves the clarity and soundstage of the earphones" and HDSS or High Definition Sound Standard tech (more details can be found at the HDSS site) and that "Both technologies serves to reduce distortion in earphones, improving clarity and soundstage." Things that are note worthy and what I'll look for in the sound section more deeply.

Unboxing: The Alpha & Delta D6 comes in a simple box with a clear plastic cover displaying the IEMs and branding. It's may not be the most efficient in terms of space saving, the contents will actually surprise you after you open it.

The D6's accessories are pretty generous, there are 9 pairs of silicone tips with various bores and shapes, 1 pair of foam tips, 1 pair of ear wire guide, a shirt wire clip, a leather cable organizer and a beautiful leather pouch. The manual and the IEMs make up the rest of the contents.

Cable: The D6 cable is an eight core silver plated copper (SPC) cable that "allows greater signal transmission, ensuring great clarity." This cable is beautiful to behold, functional, flexible, has softness and has (for me) the perfect mix of smoothness and tactile grip along with a reinforced Y-split with the company branding on the metal housing, it looks high class.

The D6 plug is made of hard plastic, reinforced by a metal sheath and protected by a metal spring at the wire exit of the plug, this helps it absorb impacts and acts a strain relief to help the cable withstand abuse.

Build/Design: In the D6 thumps the diaphragm of a 10mm dynamic that's designed to work with the dual chamber and HDSS system and tuned by Alpha & Delta themselves. Designed like a 'bullet' and machined smooth with no sharp or angular edges, this IEM design translates to a quick insert and removal, and a simple universal fit design. The size and shape of the D6 will very likely protrude from shallower ears and definitely is not the best to wear when you want to sleep while listening to music. And though the provided tips give a good seal music wise, they do not block out external noises well. Like without music playing through it, I could hear the soft hum of the air conditioner as well as most keyboards clicks.

There are 2 outlet holes on the D6, one near the bottom stem of the nozzle and one on top of the shell (has a metal mesh screen), the one near the nozzle helps avoid driver flex and the one on top is part of the dual chamber design and HDSS. There is a very small L and R at the strain relief in the same direction as the nozzle which incidentally is covered by a very fine mesh that will likely protect the insides from small dust particles as well as the occasional ear wax pieces. As a whole, the D6 feels solid and gives you the comfortable feeling of durability.

Sound Analysis: When I first listened to the Alpha & Delta D6, I knew it was good, there was all the things I wanted, good bass, great mids and highs, ample layering prowess and stage with a fun sound signature overall. But I also knew there was more to it than that, the tech involved was relatively new to my ears and my own sound signature bias played a role at first, but slowly, the picture of how the D6 sounds revealed itself the longer I listened to it. And now after 200+ hours of music, I'd like to present my findings.

Bass: The D6 sounds near neutral in the bass department but that doesn't mean it's a bad thing. With minimal boosting of the bass, the sub-bass of the D6 sounds natural with it's rather deep extension but average quantity, this translates to the sub-bass reaching deep with a more upbeat rumble. Bass hits with a natural weighted impact, Get Lucky's bass beats will be felt in an unobtrusive but palpable way, I daresay, just the way it was meant to sound and feel without overwhelming the listener. The bass decay is a bit quick and controlled with enough warmth that gives the listener an overall clean yet smooth experience.

Mids: Being a lover of mids and vocals, the D6 gives me a satisfying musical experience as the general middle frequency is slightly forward with very good levels of detail and natural timbre. Vocals sound clean and clear, from a Foggy Day to Photograph, male vocals sound crisp and distinct while female vocals share those traits blended with a more forward position, this allows songs like Do What You Have to Do, to shine with emotive prowess.

Treble: The highs are well extended, defined and controlled, though you won't call the treble smooth, the D6 is neither harsh or sibilant. Listening to Who Will Save Your Soul's acoustic guitar strings floating into your ear with gentle abandon, above and apart from the vocals and other instruments will show how much natural airiness and crispness the D6 has to offer. Details here (applies to all frequencies to some degree really) shine due to the clarity, stage and layering provided by the D6's dual chamber design and HDSS.

Soundstage: The D6, thanks to the two techs designed into it, have a great amount of depth and width in it's soundstage, with sounds and vocals coming more from outside your ear and depending on the track, can extend to a few inches outward in all directions. Positioning is pretty accurate and overall sounds natural, specially for live or acoustic recordings. The separation, layering and detail retrieval is quite good and helps the D6's overall sound to be clean, clear and delicate (ie. very fine in texture or structure; of intricate workmanship or quality - as per dictionary meaning).

Comparison: Ibasso IT01 vs Alpha & Delta D6
The IT01 has a harder bass impact and a slower more emphasized rumble than the D6 but both have nearly the same depth of extension with the D6 having clearer resolution of bass notes.

Mids: The IT01 has a bit of a V shape to its signature and the mids are a little bit recessed because of it compared to the more forward mids of the D6 in both male and female vocals. The IT01 has a bit more thickness than the more natural tonality of the D6, this gives the perception that the D6 is clearer in comparison and the IT01 smoother.

Treble: The IT01 and D6 have similar tonalities, though the IT01 comes a bit ahead having a little bit more sparkle and the D6 with a little bit more clarity and upward reach in the upper treble area. Control of harshness and sibilance is effective and similar with both the D6 and IT01, but the IT01 sounds a little tight with regards to cymbal crashes where the bloom of the reverberating crash is shorter and sounds a little less natural.

Soundstage: The horizontal stage width of the IT01 is wider than the D6 by a small margin though they share the same height and depth. Detail air, retrieval, separation and layering are again similar overall with a little bit of an advantage towards the D6.

Conclusion: The Alpha & Delta D6 is an excellent sounding balanced IEM with a bit of an emphasis on the mids and vocals, where it's a near perfect blend of natural tone, layering and clarity. Coupled with goodly responsive bass, crisp airy treble, a no fuss beautiful 8-core cable, solid tank like build and amazingly generous accessories backed by a 3 year warranty, the musical D6 is a strong contender for you money in this price bracket. I'd recommend this for daily usage when you just want to leave your TOTL IEMs at home and still have something really good to listen to on your travels or if you like very good mids while having a near natural and balanced sounding IEM with good details, staging and durability.

Pros: Near neutral and responsive bass, clear and detailed mids, spacious and natural highs, good staging and layering, solid build, excellent 8-core cable, amazing accessories, 3 year warranty.

Cons: Non replaceable cable, visual indicator of L and R not easily seen (a Blue/Red color band anywhere near the strain relief and shell could have fixed that)

Sound testing was done using a Sony WM1a (Primarily), a Hiby R6 and Zishan Z1(for comparison) and a phone (for checking driveability) volume matched to 90.X db of max volume for safe hearing below 8 hours of use and calibrated using a 1kh tone on a dedicated DB Meter, all sources patched through a switcher. More information will be available on the About Me page (once I find the time to write it up.)

Pros: Build Quality, Price/Performance Ratio, Comfort, Airy Sound, Huge Soundstage, Clarity, Detail, Transient Presentation, Dynamics, Versatile, Fun, Colored, Huge number of accessories, Sleek Design, Super leather-y carrying case
Cons: Light on the bass side, Covering the front port for more bass introduces driver flex, no detachable cable

Alpha Delta D6 - Light Airy Snappy

We just reviewed Alpha Delta D3 a few weeks ago, and we promised we'd return with a review on D6. Costing a little more than D3, we're quite intrigued to see what what Alpha Delta has in store for us at a higher price point.


It is safe to say we had a great experience with D3, and while they clearly weren't the most typical IEMs in terms of pure signature and tuning, they surely offered an excellent price and build quality, and most people who own them are having a lot of fun with their purchase, so it would be unfair to speak ill of them. Alpha Delta, an upcoming company from Singapore, is quite friendly, and easy to rely on. We're sure that they will answer all fan and customer mail and that they will be helpful to help you solve any kind of issues, if any are to arise. The fact that their products are built so well is a really nice thing, especially considering the price point those are sold at, but the signature and tuning of D6 won't be the most typical out there either.

It should be noted that I have absolutely no affiliation with Alpha Delta, I am not receiving any incentive for this review or to sweeten things out. This review is not sponsored nor has been paid for by Alpha Delta or anyone else. I'd like to thank Alpha Delta for providing the sample for this review. The sample was provided along with Alpha Delta's request for an honest and unbiased review. This review will be as objective as it is humanly possible, and it reflects my personal experience with Alpha Delta D6. Every opinion expressed is mine and I stand by it, the purpose of this review is to help those interested in Alpha Delta D6 find their next music companion.

About me


First things first, let's get the packaging out of the way:

The package is fairly similar to that of D3, and while not much has changed, not much did have to change. The biggest difference is the fact that now the face of the main package is transparent and one can take a look at D6 before they open the package.

The package is as all-inclusive as ever, Alpha Delta being quite the champs when it comes to including a lot of accessories with their products. There is a carrying case included with D6, which, just like that included with D3, feels more leathery and higher quality than most leather products, probably because of their softness and nice texture of their case.

The other interesting aspect when it comes to the package of their products is that Alpha Delta seems to have a taste for including interesting, although not always quite that useful extras with their IEMs, like those ear hooks.

All in all, with D6 you are receiving a carrying case, three types of silicone tips, each of them in 3 sizes, a shirt clip, and a cable holder.

There's not much we could have asked for from Alpha Delta, and especially not at this price point, the package content is pretty much a golden thingy to have, considering that D6 costs around 100 USD.

What to look in when purchasing an entry-level In-Ear Monitor

Technical Specifications

Driver unit: 10mm dynamic driver
Impedance: 16 ohm
Rated power: 1mW
Frequency Response: 10 Hz- 40 Khz
Speaker Sensitivity: 105 +/- db/ mW
Cord Length: 1.2m silver plated copper cable (each core contains 22X 0.05 silver plated copper wires)
Plug: 3.5 mm

Build Quality/Aesthetics/Fit/Comfort

The build quality of D6 is excellent, they are build like a tank, they are made out of metal, and their cable is quite thick, slightly soft, so it doesn't prove to be an issue while using them portably, and the IEM body has a pretty ergonomic barrel-type shape, which means that you can wear them both straight-down and over-the-ear.

This might be a little elephant in the room, but there is a huge stress strain relief on the cable, next to their 3.5mm connector. This one is made from what seems to be a spring, and it is quite long, considerably longer than most stress strain reliefs found on other IEMs. This gives D6 a sense of an Industrial-look, and might protect the cable for those who tend to be a little more rough when it comes to the jack and cable of their IEMs.

The overall IEM has one foot in the industrial type of design, while the other foot is placed in the more edgy type of design. The thicker white cable, along with the large stress strain reliefs, and the overall IEM shape feels pretty industrial and will surely appeal to those looking for this kind of IEM, while the metallic surface, along with D6 being very reflective makes them stand out when it comes to their edgy side.

The fit is fairly good, but the IEMs are on the larger size, being shallower in fit when compared to D3, and being harder to fit than their little brothers. The isolation is also much lower, D3 being quite good-isolating, while D6 isn't quite that good in isolation, as they have two vent ports on each IEM, resulting in a pretty airy and open IEM, but sacrificing some isolation along the way. They tend to feel a bit large regardless of how they are worn, so if you have really small ears, D3 or other IEMs might make a better fit, but this isn't very bad, just something we felt we should mention when it comes to D6.

The overall IEM feels really well build and put together, all parts combine well, and everything feels as part of the same IEM, thing which makes us pretty happy, as for this price point, they really feel like solid value right now, especially when it comes to their build quality.

Sound Quality

The signature of D6 is also a pretty odd one. If you haven't read our review on Alpha Delta D3, we invite you to, because a lot of things will make more sense. It seems that Alpha Delta prefers to create more unique tunings for their IEMs, thing which will be quite good for those looking for a more colored signature, but it also means that you should give them a listen before purchasing.

The baseline signature feels natural, light, tight, airy, really well expanded, thin, really well extended in the treble, while the bass is pretty well extended, but the amount gets lower especially once you drop lower than 50 Hz. Basically, they sound like a pretty good midrange pair of bookshelf speakers would sound like in general, with a really large soundstage, clear airy musical note rendering, but with a bass that is less in amount than the midrange and the treble. The midrange is mostly quite natural, voices, and especially female voices feeling natural and well presented, while male voices feel a tad thin at times, especially when you're listening to death metal.

Starting with the bass, the bass is tight, and extends pretty low, but it is considerably lower in amount when compared to the midrange and the treble. This makes it also pretty light and fast, but it doesn't have a lot of impact, most of the impact in D6 being found in their midrange and treble. This also means that one will be able to distinguish fine nuances in the bass pretty well, especially for the price point of D6, but ultimately, if you're a basshead, D6 won't provide the deep and rattling type of bass bassheads are searching for.

The midrange is open, clear and pretty darn sweet. The midrange doesn't have a significant dip or peak in its range, but it is a little forward when compared to the bass, and it is pretty much at the same level as the treble. The tonality is natural, to slightly thin, thing which works very well with gentle female vocals, but doesn't work as well with male vocals, especially if the male vocals are supposed to be deep and strong, like those in death metal music, but music that's supposed to be more calm works really well, especially Pop, Jazz, and classical Rock or Heavy Metal.

The treble is well extended and airy, it has a good amount of sparkle and energy to it, but it is on the smoother side texture-wise being more the non-fatiguing type rather than the busy and grainy type. There's fun in every song, and everything sounds exciting and interesting, without becoming too hot. There's not much of a peak or a dip here either, the treble being extended until 9 - 11 kHz, after which is falls down very slowly, resulting in an extended and airy sound.

Now, one thing we didn't really mention, but other reviewers did start with, is that you can get another kind of signature from D6. In short, there is a vent port on the bore / the tube that enters the ear, which you can cover with the silicone tip. We generally advise against this because it leads to issues with the comfort, since if you do this, D6 has driver flex, and isn't nearly as comfortable as when the silicone tip is seated normally, but covering that port basically recovers the bass to a normal to bass-head levels, thickens the sound, all while keeping the PRaT and ADSR characteristics intact, along with D6's airy and well extended sound. Actually, if the comfort could be better with that port covered, this would be a true champ in this price range, but as things are, we can't say this is the best solution, more like a compromise you might want to look into, if you want one of the most interesting V-shaped signatures.


The soundstage of Alpha Delta D6 is extremely wide, precise, with a really amazing instrument separation and a great overall imaging. There's literally only good to speak about their soundstage, and it is much much more extended than we'd have expected or assumed it would be before listening to them, but the main downside is that it comes at the cost of bass. With the frontal vent covered, this soundstage is affected a little, but still is amazingly large, while with the front port open, the sound is really well extended without any issues. If you're looking for a really airy sound, with a large soundstage and outstanding instrument separation, especially for 100 USD, then D6 surely will not disappoint.


The ADSR and PRaT (Texturization) is natural to quick, guitars and other instruments having excellent overall textures. There isn't quite that much to talk about since they still are within the revealing abilities of 100USD IEMs, but the overall sound is revealing and slightly analytical, having a great amount of juicy detail and textures in guitars, and most instruments not feeling smooth or liquid, but neither too textury or revealing.

Portable Usage

The portable usage is, in one word, good.

Alpha Delta D6 is very easy to drive from most portable sources, so that will not be an issue for anyone who's planning on taking them on a walk, and they are quite comfortable, their cables being the right type of cables to have on a IEM to want on a IEM you take on a walk with you, but where they lose in portability is in their isolation, which, is not quite that good in the end.

There is no driver flex, no microphonics, no issue we can note. They aren't especially prone to hiss, there being almost no hiss with Hiby R6, and you can pair them with most smartphones and still get great results, so there's no issue with using them portably.

Since they are pretty comfortable, they won't cause issues like the IEMs falling out of the ears while walking, or even jogging, and there is a wide selection of tips included in the package when you purchase D6, but if you plan on walking through an area with large amounts of noise, you might wish for a bit more isolation. Covering the frontal vent port does help with the isolation, but only so much, so in the end you might want to take a look at something slightly more isolating, like even Alpha Delta D3, if you are a really quiet listener who goes through high-noise areas with your IEMs, although D6 will do just fine if you walk through a park and listen at moderate or higher volumes.

All in all, their portability remains good, but if you're looking for something to always have on you while walking, there are slightly better options out there, even Alpha Delta's own D3 being slightly better in this aspect.


All the IEMs D6 is compared to are from a similar price range, but with different tunings and signatures.

Alpha Delta D6 vs Westone UM1 - Starting with the build quality and the package, the most interesting aspect is that the two are similar in most aspects, just not the fact that UM1 comes in plastic, with a full plastic shell, and has a thinner cable, while D6 comes in a metallic shell, and has a thick and reliable cable. On the other hand, of the two, UM1 has detachable cables, while D6 does not. The isolation is much stronger on UM1, which is small and closed, has a really deep fit which will cut you out from the outside noise, while D6 is pretty open in its nature. The tuning is extremely different, with UM1 being dynamic, impactful, thick, bassy, warm, dark, smooth and slightly intimate, D6 being, by comparison, extremely open, light, dynamic, quick, revealing, airy, and brighter. If you're looking at the comfort, UM1 tends to have a smaller shell and be more comfortable, while D6 has a larger overall body, but not by a large margin. For a more versatile IEM, with more detail, we recommend D6, while if you're looking for a really thick and warm IEM with a relaxing overall signature, UM1 sure is still amazing.

Alpha Delta D6 vs FiiO F9 - FiiO F9 comes with a more advanced package, and although their carrying box isn't half as soft to the touch as that of D6, it is much more useful, as F9's Peli-kind of carrying box will ensure the safety of your IEMs, even if it falls out onto the pavement, or if you step on it, while the carrying box of D6 will not protect them against pressure as well, being a soft-carrying pouch. The cables are detachable on F9, and the version we tested also came with two cables, one of which is Balanced, so there's a little plus in value there, but the single cable on D6 is thicker in size and looks a bit more pro-like in direct comparison. The cables of F9 being a bit thinner might also be a plus for their portability. The isolation is much stronger on F9, which is a really well-isolating IEM, especially when compared to D6, which is pretty open in its nature. The comfort is similar between the two, although F9 has a smaller body, but F9 can only be worn over-the-ear, while D6 can be worn straight-down as well. The tuning is a little different, with F9 having a bit more bass, slower overall transient response (so a smoother overall texture rendering), a bit of a peak in the hot area of the treble (6-9kHz), and a bit more emphasis on emotion. The D6 quickly makes itself remarked with a lighter and a quicker sound (so more texture revealing abilities), more emphasis on air and soundstage size, with its soundstage being larger, with more instrument separation, with a slightly thinner midrange, and with less bass amounts. The overall feeling is that F9 is a bit more intimate, but a bit more even and more natural, while D6 is lighter, more revealing, but with less impact in the bass compared to F9, although it does have a larger soundstage.

Alpha Delta D6 vs Kinera H3 - Kinera H3 is an interesting IEM to compare D6 to, because most people might feel that the two are similar, especially if not paying utmost attention to some details in the sonic descriptions of the two IEMs, but starting with the build quality, although H3 has detachable cables, and comes with a good, hard carrying case, it has a larger IEM body, it suffers from Driver Flex, and it has plastic bodies, while D6 has metallic bodies, has no driver flex if the tips are positioned in the normal position, so not covering the vent port, and D6 has a nicer (thicker and more reliable) cable, which is less prone to tangle by default. The comfort can become affected by driver flex on D6 as well, if you cover the frontal vent port. The noise isolation on H3 is much better, since they are both closed, and larger in size, blocking more noise passively. The sonic character of the two IEMs is quite different, especially in the midrange. The bass presentation is quite different as well, with H3 having a deeper bass, with more emphasis on the bass impact, although it has a similarly tight and quick bass like D6, where D6 has less bass in amount in the general sense. The midrange is where the largest difference is, with D6 being much more forward in the midrange, while H3 is much more recessed in the midrange, H3 having almost 20 dB of midrange recession compared to their treble, while D6 barely has any. This results in a distant midrange for H3, while it also results in a slightly forward one for D6, especially by direct comparison. The treble, on the other hand, is quite enhanced on Kinera H3. D6 has its treble in line with the midrange, while H3 has its treble boosted by about 20 dB when compared to its midrange, leading to a really V-shaped sound that can be a bit too much, especially with certain music styles. In direct comparison, D6 feels more even, with only the bass being a bit lower than one might ideally want for most music styles, and a bit tighter as well, but with the PRaT and ADSR being really good and the soundstage being really open, while H3 feels a bit more detailed, but with a much more uneven signature, which is aggressively V-shaped and aggressively bright, with a really analytical side to it, which will reveal details more, and with a more intimate soundstage. Both IEMs do extremely well in terms of instrument separation. At the end of the day, D6 is the more universal IEM here, but H3 is a magical, unique IEM which still has a special place in our hearts. We'd recommend D6 for someone who is looking for a light and open-sounding IEM with a vast soundstage, and H3 to those looking for a more V-shaped experience, with more bass, and with more isolation from the noise.

Recommended Pairings

Alpha Delta D6 reponds fairly well to being paired with a higher-end source, but this doesn't seem to be absolutely essential, and they will work just as well with a less expensive source, like the average smartphone.

Alpha Delta D6 + Cayin N5ii - N5ii is still a favorite source for us, since Cayin managed to not only give it a good price, but two microSD slots, a beautiful design, streaming abilities, and Android firmware, so the abilities of this one are practically endless. The sound is slightly warmer and thicker than with most sources, thing which is great for D6, since they were a bit on the thinner side and had a light bass. You can also apply a bit of EQ to D6, leading to a thicker and stronger sound, since N5ii has this ability hassle-free.

Alpha Delta D6 + FiiO M7 - FiiO M7 is another favorite ultra-portable, which is able to give a lot of life to D6. Although D6 isn't wireless, so you aren't taking advantage of M7's strongest point, M7 has a great neutral sound, and it has support for EQ profiles from FiiO's app, so you can always give D6 a thicker sound by increasing the first 3 sliders of that EQ with a few dB's. If you're planning to get M7 soon, FiiO also has a little sale for it, where they include FiiO F9 SE with it, so together with D6, you'd have two different signatures to enjoy and switch between when you want to try something new.

Alpha Delta D6 + Burson Play - Since we considered the pairing with M7 and N5ii, we should also try D6 with a true desktop-class device, like Burson Play, which is an amazing DAC/AMP for desktop. Compared to most sources, it seems to have a better extension both ways, and a more energetic overall sound. Textures seem slightly enhanced, and the impulse response time seems a tad quicker, while the overall sound just feels more vivid and open. Since we're talking about a DAC/AMP which can also run from Windows, you have the might of Roon and other high-end software at your fingertips, including high-quality DSPs like EQ profiles to change the tuning of D6 and add more bass to them.

Value and Conclusion

Listening to Alpha Delta D6 has been a lot of fun, and with the tuning Alpha Delta gave to it, it will be a lot of fun for other listeners as well.

Starting with their price, they are priced at roughly 100 USD, which places them in a pretty heated market segment, where a lot of IEMs pop up, but only the strong survive for a little longer.

They are up against many, but Alpha Delta has taken the right steps by giving D6 a great build quality, and a great package. In fact, they are made out of metal, while their cable is one of the thickest and most serious-looking on a IEM at this price, with the only serious downside being the fact that the cable is not detachable, so you'll need to send them to Alpha Delta if any problem is to arise. On the other hand, they have taken some great steps in making sure that the cable will last for a long while, having included a very serious stress strain relief on the cable, along with a high build quality for the whole IEM.

The package comes with more tips than you could wish for, and the carrying box, while not exactly protective, is one of the finest coming with a IEM, if we're talking about the aesthetics and the softness to the touch. There are ear hooks, and a shirt clip in the package as well, and while we feel most users will not require any of those, they sure are nice to have in a package for those who will require them.

The sound quality, and the tuning, ultimately, are something unique. D6 doesn't focus on the bass, instead focusing on the midrange and the treble, and giving music a tight, light, quick, and airy feeling, just like a pair of bookshelf speakers would usually do. You have access to all the might of your favorite music, along with the soundstage of a much more open listening setup. The sound is generally dynamic and vivid, with good detail and with a playful approach, while the treble is smooth, but well extended. What should drive your decision is whether you prefer a tighter or a larger bass, although even that can be fixed either via EQ, or via strapping the silicone tips over the front vent, resulting in even more usage scenarios for your D6.

If you're looking for a fun, light, open-sounding, accessible, and well-build In-Ear Monitor, then Alpha Delta D6 is surely worth looking into, and if you're the type who prefers a lighter and a tighter bass, a more airy sound, with a larger soundstage, and with an amazing amount of detail and textures, then you should really add them to your shortlist, because those will surely bring you a lot of fun if you decide to get them.

I hope my review is helpful to you!

Stay safe and remember to always have fun while listening to music!

Contact us!
(Click Buttons)

Pros: price/value, durable design, sound sig controlled by a nozzle vent, premium 8-core SPC cable, quality accessories, 3-year warranty.
Cons: cable is not detachable, L/R marking is hard to see.

The product was provided to me free of charge for the review purpose in exchange for my honest opinion. The review was originally posted on my blog, and now I would like to share it with my readers on head-fi.

Manufacturer website: Alpha & Delta.


I have been focusing on so many flagships that sometimes overlook interesting budget releases. I still get a lot of those for review, but not everything catches the attention, especially due to my limited time. I have reviewed Alpha & Delta debut AD01 about 3 years ago, and remember being quite impressed with a sound and a build quality, especially build quality. New D6 caught my attention because right away I noticed a non-detachable cable and 3-year warranty, indicating that AD has a lot of confidence in durability of their design. But the biggest surprise came when I started to listen to it.

While they have a nice mid-forward sound out of the box, when I used Veritas coupler to measure FR, I noticed a significant boost in low end response. That’s not what I heard when listening to D6 with my ears. Looking closer, I realized that while I pushed these IEMs into a coupler for measurement, the core of eartip slid all the way to the back, covering the front vent. That’s how I discovered this “easter egg” trick to turn D6 into dual sound signature, controlled by eartip placement on the nozzle. It was my “Eureka” moment, and I even went back to check other D6 reviews, though nobody mentioned that.

That sealed the deal for me to start working on the review, to share with my readers not only about these iems in general, but also about how you can “flip” the bass boost switch depending on eartip placement. Here is more about it.

Unboxing and Accessories.

Packaging here has a bit of an “old school” feeling with a clear display window so you can preview IEMs even before opening the box. It’s a nice touch, considering many manufacturers today have a solid packaging box with some artwork print on the top. D6 was securely wedged in a foam cutout, with all the accessories underneath.

ad_d6-01.jpg ad_d6-02.jpg ad_d6-03.jpg ad_d6-04.jpg ad_d6-05.jpg

Accessories include a pair of ear guides (that’s an old school for sure) which might come handy if you want to wear D6 wire up, a shirt clip, a pair of foam eartips (non-Comply), and 9 pairs of silicone eartips in various shapes (3 sets of S/M/L, one silicone rounded, one silicone with a more cone-shape, and one hybrid with thicker core). Those are basic accessories, but to take it to the next level, AD included a leather case and a leather cable wrap. I have seen some budget iems with a leather case, but those are usually pleather glued cases. Here it feels and smells like a genuine quality leather, both a case and a cable wrap.

ad_d6-06.jpg ad_d6-07.jpg ad_d6-08.jpg ad_d6-09.jpg ad_d6-10.jpg


In the heart of the D6 is a 10mm dynamic driver inside of a very lightweight metal bullet shell housing with a dual air chamber acoustic design. They even went as far as licensing technology behind HDSS (high definition sound standard) to ensure low distortion, higher clarity, and improved soundstage expansion. The back (faceplate) of D6 shells has AD logo and HDSS label to show the licensed tech inside.

ad_d6-19.jpg ad_d6-20.jpg ad_d6-21.jpg ad_d6-22.jpg ad_d6-23.jpg ad_d6-24.jpg ad_d6-25.jpg

Top of the shell has a vent for the back venting of the driver, while the nozzle of the shell has a front venting at the bottom. The front vent, which is easy to miss, is the key to its unique dual sound sig. In theory it wasn’t designed to have dual signature, so you can refer to this as a mod. But it’s so easy to control that I consider this to be almost like a feature due to a very noticeable sound difference. The nozzle has a mesh cover and a lip at the tip, to protect eartips from sliding off, followed by what appears to be a notch which works as a stopper to keep the front vent open.

So, when you push the eartip in, it stops after that notch, leaving the vent open. But if you slide it further to the back of the nozzle – it closes/covers the front vent. I will refer in my sound analysis to sound with vent open and closed. Just one thing you must keep in mind, when closing the front vent, you are not only controlling the bass response of the sound, but can also introduce a driver flex (that click when you insert the iem in your ears) because you are blocking front air escape. That could be fixed by tip rolling, to relax the seal which eliminates driver flex and reduces the bass slam when vent is closed.

ad_d6-26.jpg ad_d6-27.jpg ad_d6-28.jpg ad_d6-29.jpg

The cable is attached to the shell at the bottom and has a flexible rubber strain relief. That rubber boot/strain relief has L/R imprinted on the inside, but it’s nearly impossible to see that marking. Instead, the left side strain relief has a bump which is easy to feel, being an indicator of the left side since shells are identical otherwise.

Cable is truly high end, with 8 braided SPC (silver plated copper) conductors. Yes, it’s a pity that cable is not detachable because it’s high quality and would have been great to use with other iems. I can only guess that due to dual air chamber design, the detachable socket would have been sticking out too far, and perhaps AD tried to avoid that. But keep in mind, they have a lot of confidence in reliability of these IEMs, thus include 3-year warranty. So, with cable, you have 4 braided conductors on each side going down to a nice cylindrical y-splitter with Alpha & Delta logo, and then continue in a neat 8-wire braid down to 3.5mm single ended TRS connector.

Wires are soft and have a nice clear shielding, and even with 8 wires in the braid, the cable is still flexible. There is a little bit of microphonics, but it’s not as bad and you have included shirt clip if it bothers you. The L-shaped headphone plug is nice, with rubbery housing and metal boot, and it has a very cool spring strain relief. The only wishful thinking considering multi-core design – too bad it’s single ended and not balanced terminated, though I do have to remind myself this is still a premium cable with an under $100 product. One thing that was missing here is a chin-slider which would have been a good idea, not as much when you wear wires down, but when you attempt to wear them up. You can probably make a DIY chin slider with a rubber band.

ad_d6-12.jpg ad_d6-13.jpg ad_d6-14.jpg ad_d6-15.jpg ad_d6-16.jpg ad_d6-17.jpg ad_d6-18.jpg

The fit.

ad_d6-32.jpg ad_d6-33.jpg

Sound analysis.

D6 has a rather unique sound signature due to a dual vent design where depending on the nozzle vent, either closed or open, the low-end response of the sound will vary significantly. With vent open, when eartips are not pushed all the way in, you have a mid-forward sound signature where depending on pair up the bass will either be neutral-flat or neutral-balanced. With vent closed, when eartips are pushed all the way to the back, the sound sig is more balanced with a fuller body due to an elevated bass impact. In either case, the overall tonality is more natural and revealing due to presentation and rendering of mids, but it's not too bright or harsh. Even with vent closed and bass being elevated, the retrieval of details is pretty good, and you get a decent separation and layering of sounds for an entry level model.

Soundstage has a very good width and depth, way above the average width, a more typical oval shape with a sound slightly out of your head. Positioning and imaging of the sounds is good, not the greatest, but pretty good. With vent open and more emphasis on mids, I heard a better imaging, while with vent closed and more bass impact, for some reason positioning of some of the instruments where closer to the center.

In more details, bass is very much controlled by a vent in the nozzle. When it's open, bass is neutral flat, with a slight variation between pair ups where it could get a little bit lifted. It has a good extension, but closer to a neutral quantity. As soon as you close that vent, the mid-bass slam scales up significantly and the sub-bass rumble also gets a boost in quantity. It feels like someone flipped a bass switch on. With a “neutral” bass, there is more control and shorter decay with an average attack, while the “elevated” bass has a little bit of spillage into lower mids, giving it more body without muddying it.

Lower mids can vary from neutral to being slightly below neutral due to vent being open/closed. With vent closed, you can certainly sense more body in the sound. With upper mids, when vent is open you have more emphasis and a little less body, so they take a front stage with all the focus, becoming more layered, more separated, with a great retrieval of details, but not on micro-detail level, keeping it still natural. With vent closed, upper mids get a little more organic tonality and some additional warmth.

Treble is consistent between vent closed/open, being well defined, crisp, very extended, with a natural airiness. Depending on pair up, the level of crunch can vary, and I even heard a hint of sibilance found paired up with R6 which has 10ohm output impedance, but with iEMatch it got smoother. With many other sources, lower treble was under control. Treble has plenty of clarity and a very good extension. When I did quick measurements, as expected, I saw a peak around 12k (gives a nice clarity and definition to a treble), and then further up there was another peak in treble extension.



In these comparisons, I stacked up D6 against a few other IEMs in a similar price/performance category, and made a note of the effect of nozzle vent open/closed position. In every case IEMs were volume matched, and I tried to focus on a technical and sound breakdown comparison.

D6 vs Oriveti Basic - D6 has a wider soundstage, both in width and depth, while Basic soundstage expansion is more intimate. When it comes to sound signature, Basic is L-shaped with a serious low-end slam, especially with a focus in mid-bass. D6 with its vent closed has a noticeable bass lift, but it's more balanced across FR, giving a sound more tasteful v-shaped signature, instead of shifting the attention to low end. With vent open, D6 bass is significantly more neutral in comparison to Basic. In lower mids, Basic is north of neutral since bass does spill in there, while D6 with vent closed has more neutral lower mids and with vent open even a bit south of neutral. Upper mids are smoother and warmer in Basic, while D6 is more layered, more revealing, still organic but not as warm and more transparent. Treble has more sparkle and better definition and extension in D6 as well.

D6 vs Simgot EN700 Pro - D6 has just a slightly wider soundstage, while both have the same staging depth. When it comes to overall signature, EN700 Pro is right between the D6 with vent closed and open. 700Pro bass is more elevated than neutral bass of D6 with vent open, yet 700Pro mid-bass doesn't have as much slam in comparison when D6 vent is closed, though sub-bass extension is similar. With lower mids, both have neutral presentation (with D6 vent closed). Upper mids in EN700 Pro are pushed a little back, a little brighter and less natural in comparison to a more balanced (when vent is closed) mids of D6 which also sound more natural and more layered. Treble definition, crunch, and extension is similar between these two.

D6 vs iBasso IT01 - Another very interesting comparison. While IT01 soundstage is wider, both have a similar depth expansion, a little more out of your head. With a sound signature, IT01 is a classic example of v-shaped tuned IEM, while D6 even with a vent closed has a more balanced signature across FR. IT01 bass hits a lot harder in mid-bass, while D6 w/vent closed does have a nice slam but it's rather polite in comparison. Both have a similar sub-bass extension, though IT01 has a little more rumble. D6 with vent open is night'n'day in comparison when it comes to bass since it's too neutral. IT01 lower mids are little more recessed in comparison to more neutral D6. Upper mids have some similarities in tonality, being natural, layered, and still very detailed, but in IT01 - upper mids are pushed more back, while D6 has them more forward, with a more balanced presentation. Both have a very well defined crunchy treble with a nice extension and airiness, but IT01 has a little more sparkle while D6 is more natural in that regard. I think those who find IT01 bass slam a bit overwhelming and want mids to be more forward, will enjoy D6 with a vent closed.


Pair up.

With impedance of 16 ohm and sensitivity of 105dB, D6 is very easy to drive, maybe just needs a few extra clicks of volume since sensitivity is a bit on a lower side. Also, I didn’t hear any hissing in any of my pair up examples.

A&K SP1000 SS - Very wide soundstage with excellent depth as well. Sound signature is more balanced with vent closed, where I hear a deep sub-bass rumble, punchy elevated mid-bass; neutral lower mids, forward upper mids with a great layering and separation, and transparent natural tonality, and great retrieval of details; treble is crisp and well defined, extended with a nice airiness, and overall having a natural crunch without being too harsh or splashy. With vent open, bass is flat neutral, extended but has a neutral quantity; lower mids a little south of neutral, upper mids are more forward, brighter, very natural, layered, excellent retrieval of details; and treble is crisp, airy, and extended. With vent open it has a more mid-forward signature, but a little smoother at the top.

Cayin N5ii - Very wide soundstage expansion with a nice out of your head depth. As expected, sound sig is more balanced with vent closed and more mid-forward with vent open. With vent open the bass is flat, and when it's closed - the mid-bass slams even harder. Mids have excellent retrieval of details, nice layering and separation, and have a more natural tonality. Treble in this pair up has more sparkle, more crunch, higher definition, still very extended and airy. This pair up is a little brighter in tonality.

iBasso DX150 - Very wide soundstage expansion with an excellent depth. With vent closed, sound signature is balanced, though pushing a little close toward the L-shaped due to a deeper and stronger sub-bass and more mid-bass impact. With vent open, bass is neutral, but a little more elevated with a more noticeable sub-bass rumble in comparison to other pair ups. Lower mids are neutral, while upper mids have a very natural organic transparent tonality with an excellent retrieval of details and nice layering and separation. Treble is well defined, with a moderate crunch, great extension, and polite airiness. This pair up is a little smoother.

Shanling M0 – I hear a wide soundstage with an excellent depth. With vent closed, sound signature is a little more L-shaped, though still closer to balanced, but I do hear a little more sub-bass rumble. Mid-bass impact is strong for sure. With vent open, bass is neutral, but not exactly flat, still has a nice sub-bass extension with a textured rumble and a bit of a punch in mid-bass. Lower mids are neutral with either vent open or closed. Upper mids are natural, detailed, not as layered as in other pair ups, but sound does have a good separation. Treble is well defined, crisp, a little on a brighter side, but not harsh or splashy.

Hiby R6 - Very wide soundstage with an excellent depth. Was very curious about this pair up due to 10ohm output impedance, which in theory shouldn't affect a single dynamic driver iems. With vent open, the sound is more mid forward, but bass has a nice extended sub-bass with a tight mid-bass punch, above neutral level. With vent closed, the sound signature is more balanced, but the bass is not as elevated as I heard it with other DAPs. It's above the neutral, has a deeper sub-bass with more rumble and stronger mid-bass punch, but it's more balanced against the rest of the spectrum. Lower mids in either case are neutral, and upper mids are very layered, nicely separated, excellent retrieval of details, and slightly brighter tonality. Treble is bright, crisp, airy, very extended. It's not harsh or splashy, but it does have a little bit of sibilance with a few of the tracks. When adding iEMatch in series, there is hardly any change in tonality, but that hint of sibilance was absolutely gone.



Lately I got a few pings from people with a collection of flagship C/IEMs who are looking for something “budget” to use on the go. I know, “budget” is a relative term, especially when you look at $1k-$3k flagship prices. Also, “budget” means cutting some corners to meet that budget. With D6, I don’t think Alpha & Delta had any intentions to cut corner, they tuned it to a specific sound signature, made a durable design backed by 3-year warranty, included a high quality permanently attached cable so there is no fiddling with connectors, and provided a set of cool accessories. And on top of that, obviously unintentionally, gave D6 the ability to mod the sound by sliding the eartip to cover the front vent. As a result, you get a fun little “budget” IEM in sub $100 price range. It’s a nice choice to consider if you want to give your TOTL a break or if you can’t decide between mid-forward signature or balanced sound with more emphasis on low end.
Pros: Stellar materials, fit and finish - Crisp, clear sound - Overall value (balance of sound, build, and accessory quality)
Cons: Broad housings - Sub-bass extension/emphasis are slightly lacking

Today we're checking out Alpha & Delta's flagship earphone, the D6.

Alpha & Delta (A&D) is the in-house brand of the popular retailer out of Singapore, Lend Me Ur Ears. The brand was launched with a simple but rugged sports earphone, the D2, which was well-received within the portable audio community. That was followed up by the dual dynamic AD01 which warmed the hearts and ears of many. Since then, the brand has expanded further with a number of new products. The D3 features a 6mm micro-driver which puts out one heck of a low end. The JAAP is a fully wireless Bluetooth earphone with competitive specifications like an achievable 6 hours of battery life. Last but not least is the audiophile targeted D6 that we're checking out today.

The D6 features single 10mm dynamic drivers per side with an 8 core, silver-plated copper cable connecting them to your playback device. A&D has also licensed HDSS and dual-chamber tech for use in the D6, something I am familiar with from my time with Blue Ever Blue's products. Now, I can't definitively say that the HDSS effect is in play since for that we would need identical models to compare, one with and one without HDSS. That said, I can confirm that the D6 shares qualities with other HDSS and dual-chamber equipped earphones I've got, and that's a good thing. In addition to the developments made to craft a good sounding product, A&D is also obviously confident in the quality of their materials and workmanship. The D6 is backed by a three year warranty, something that's not particularly common in the industry.

So, does the D6 stand tall as Alpha & Delta's current flagship, or is it a has-been with some neat tech but mediocre sound? Let's find out.



A big thanks Dennis with Alpha & Delta for reaching out to see if I would be interested in reviewing the D6, and for arranging a sample unit. All thoughts within this review are my own and do not represent A&D or any other entity. There was no financial incentive provided.

At the time of this review the D6 could be picked up for 133 SGD or 94.68 USD here;

Personal Preferences:

I listen primarily to various EDM sub-genres (liquid drum and bass, breakbeat, drumstep, etc.), hip hop, and classic rock. While I enjoy a variety of signatures in my headphones I generally lean towards slightly warm with elevated treble and sub-bass, an even and natural mid-range response, with reduced mid-bass. The HiFiMan RE800, Brainwavz B400, and thinksound On2 offer unique examples of signatures I enjoy.


For at home use the D6 was powered by a TEAC HA-501 desktop amp or straight out of my Asus FX53V laptop. For portable use it was paired with an LG G5, HiFiMan MegaMini, or Shanling M1. The Walnut F1 also made it's way into the rotation at times. The D6 was exceptionally easy to drive.

  • Driver unit: 10mm dynamic driver
  • Impedance: 16 ohm
  • Rated power: 1mW
  • Frequency Response: 10 Hz - 70 Khz
  • Speaker Sensitivity: 105+/- 3db
  • Cord Length: 1.2m silver plated copper cable (each core contains 22X 0.05 silver plated copper wires)
  • Plug: 3.5 mm
DSC02864.JPG DSC02863.JPG DSC02880.JPG

Packaging and Accessories:

The D6 doesn't come in any sort of packaging that's going to blow you away with layers of intricacy or upscale styling. Nope, it's pretty basic. The base grey cardboard box lists on the back the contents and accessories along with the specifications. The entire front is a clear plastic viewing window showing off the earphones nestled within a foam insert. Lifting out the viewing window reveals a gorgeous leather carrying case containing the rest of the accessories, of which there are many. In all you get;
  • D6 earphones
  • Leather carrying case
  • Leather cable tie
  • Silicone ear guides
  • 3 sets of single flange silicone ear tips in s/m/l (9 pairs total)
  • 1 pair of foam ear tips
  • Shirt clip
It seems like A&D made a trade off; inexpensive packaging in exchange for plenty of quality accessories. That's a trade off I'm perfectly happy with. The case and cable strap feel great, the ear guides are handy for over-ear wear, and the tips are all different so the variety make sense. Good stuff here.

DSC02867.JPG DSC02885.JPG DSC02889.JPG

Build, Comfort, and Isolation:

Alpha & Delta back this earphone with a solid warranty, and I can see why; it's very well-constructed. The metal housings are a dark gunmetal chrome with design inspiration taken from ammunition in the placement of the various ridges and channels. While fairly large, they are quite light and all edges are rounded off so there are no sharp edges. This is great for comfort because the nozzle is a touch on the short side meaning the inner edge of the housing is likely to lean against your ear. Other earphones built like a similar girth that do not have rounded edges cause hot spots and mild outer ear pain. Not an issue I've come across with the D6.

The cable is the real show stopper though. The D6 uses a wonderful braided eight core, silver plated copper cable. The sheath has a slightly gummy and grippy feel to it that holds on to skin quite effectively, yet slides over clothing with little resistance. This makes the included ear guides a little redundant in my opinion, as the cable sits very securely around you ear without them should you choose to wear them cable up.

Strain relief is usually an area where I have some bones to pick. For the most part, the D6 is fine here. Leading into each ear pieces is a very KZ-esque rubber relief but with just enough give to make it effective. On the left side is a tiny little bump to indicate the left channel, something A&D reminds you of with a small strip of paper found in the packaging. This is a little too ambiguous for my liking, and would prefer if they just printed a small L and R somewhere on the ear pieces. The 90 degree angled jack goes with a tightly coiled spring instead of a more traditional rubber relief, something usually only found on much more expensive products. The y-split's relief isn't fantastic being that it is so stiff there is next to no flex. Still the cable feels durable enough to make this less of a concern than it otherwise would be.

In terms of isolation, the D6 is flat out average and won't be winning any awards. Using them at work I could hear keyboards clattering away, murmuring, etc. Using them outside, cars are well present, as are other noises. These would be fine for walking around in a grocery store or going to the shop, but for transit? I'd be looking elsewhere.

HDSS (High Definition Sound Standard):

This tech boasts some interesting claims, such as a clinically tested and approved 14.32 reduction in psychological stress, detailed 3D sound reproduction, and virtually no distortion. While I'm not going to state my thoughts on some of those claims, I will state that I have tried quite a few earphones with HDSS and their dual-chamber tech, all from Blue Ever Blue. Ear fatigue seems to be vastly reduced as there is next to no back pressure once you've got a good seal. My time with the D6 mirrors my past experiences with BeB's HDSS equipped products. Those that are big on protecting their ears and hearing might want to keep the D6 in mind.

DSC02892.JPG DSC02895.JPG DSC02899.JPG


The D6 is a very coherent sounding earphone with a well-balanced signature, blending bass, treble, and mids wonderfully. Treble is uncharacteristically smooth and tight for something in this price range, especially if you've become accustomed to the rarely filtered sound of BAs used in budget hybrids. It is calmly accentuated with mild peaks in place to give it's upper ranges a very specious and ethereal presentation. Attack and decay are quick, but not so quick that lingering notes trail off too quickly. Detail and clarity are above average for a single dynamic, and serve listeners well by giving them lots of information about what's going on in any given track.

The mid-range is much the same though it has a touch more warmth to it. Timbre is spot on with instruments and vocals sounding as they should. What gets me most is how smooth vocals sound while still retaining a level of coherence you'd usually associate with a leaner sounding earphone. Throwing on “Beat It” by Michael Jackson, the awesome guitar solo is crisp and texture, though not quite as forward as it is through other similarly tuned products like the Blue Ever Blue 1200EX. It also lacks some weight and presence. The D6 fairs much better with “Billy Jean” and other tracks rich with synth work.

Bass on the D6 is elevated slightly over neutral with great texturing and decent extension. The balance between mid- and sub-bass is quite even, with neither taking on a larger presence. The D6's bass doesn't have a ton of slam or authority to it, going more for a detailed presentation than visceral. Not really my preference, but it works in conjunction with the way the mid-range and treble are presented. They're certainly not a bassy earphone, but they're got more umph down low than your typical BA only product, and some other single dynamic models like the Whizzer A15 Pro Haydn.

Another area the D6 stands out to me is sound stage, a quality I find common among other HDSS equipped earphones like the aforementioned 1200EX and 2000EX. It might be the dual-chamber design and/or plain old good tuning, but whatever it is gives the D6 a wonderfully open presentation that has no issues throwing sounds a good distance from my head. Listening to Infected Mushroom's “Groovy Attack” is a trip as effects flash around the stage. This also serves to highlight some impressive layering. Congestion is avoided as a result of quality separation as evidence when listening to King Crimson's “Starless and Bible Black”. After an agonizing 4 minute build, the track shifts gears with a mild blowing jazz attack that can get messy with poorly separated earphones. Not the D6.

Select Comparisons:

(Volumes matched as best as possible with the Dayton Audio iMM-6)

Blue Ever Blue 1200EX (105.00 USD): Like the D6, the 1200EX features HDSS with dual-chambers. The 1200EX's housings are a mix of metal and plastic with an extended nozzle section designed to hold the various stabilizing ear hooks that come with it. Because of this design and the angled nozzles, the 1200EX meant for cable down wear only, unlike the D6's more universal barrel shape which works cable up or down. I quite like the 1200EX's cable which has a very dense, durable shealth, but it's slightly stiff (especailly so in the cold) and isn't quite as well relieved. Overall build quality goes to the D6 with it's more impressive materials along with better fit and finish. The 1200EX's shell does fit my ear a little better though.

In terms of sound the two have slightly different takes on the same signature. The D6 is a touch thinner and more skewed towards upper mids and lower treble giving it a bit more sparkle and air. The D6's mid-bass is maybe a dB or two more emphasized compared to the 1200EX. Neither has particularly prominent sub-bass, but I'd give the edge to the 1200EX. The 1200EX's mid-range is slightly more articulate but equally present. It has a slightly drier texture that I feel gives it the edge with male vocals. In terms of sound stage, layering, and separation I couldn't really hear much of a difference, though imaging felt more accurate through the D6. Texture and detail between the two was again more or less equal.

TFZ Exclusive King (99.00 USD): The King's housings are mostly plastic with a metal faceplate. Fit and finish is quite good, but falls short of the D6. There is a notable gap between the faceplate and rest of the ear piece which hides some vents. The D6's build is tighter and more consistent. The King is is a very large earphone that takes up pretty much the entirety of you outer ear and is designed for over ear wear only. If you have small ears or like to wear your earphones cable down, the D6 will better meet your needs. In terms of cables, the King's cable is a much thinner braided option. It is replaceable though, terminated in a 2-pin connector. The D6's cable is nicer, but fixed.

Just as with the 1200EX, the King and D6 have different takes on the same signature. The King's upper treble is slightly more emphasized but not as smooth and articulate. The King has a more forward, detailed, and textured mid-range than the D6. The King's low end definitely has more punch to it. It hits harder, feels tighter, and is more layered and textured. It also extends deeper with more sub-bass emphasis, and a dialed down mid-bass region. The King is more in-your-face than the D6.


Final Thoughts:

Alpha & Delta's D6 is a strong entry in the ~100 USD market with a fairly balanced signature that is lightly treble-leaning; one that is very detailed, smooth, yet decidedly non-fatiguing. It could use a touch more sub-bass extension and emphasis for my tastes, but as-is is still quite pleasing. That it goes toe-to-toe and blow-for-blow with the Blue Ever Blue 1200EX and TFZ Exclusive King, two of my favorite earphones in this category, says a lot about how capable the D6 is.

While the shiny gunmetal chrome look isn't for everyone, you can't deny that it was executed exceptionally well. The D6's material quality and fit and finish is impressive as well, with good comfort too despite being a little on the bulky side. Many would think the D6 would benefit from a removable cable, however, the fixed cable that is on there is absolutely gorgeous and is well-relieved. It feels like it will last.

If you're looking for a strong performer around 100 USD, be sure to look into the D6. Thanks for reading!

- B9Scrambler

***** ***** ***** ***** *****

Some Test Tunes:

Aesop Rock - Skelethon (Album)
Daft Punk - Random Access Memories (Album)
Elton John - Yellow Golden Brick Road (Album)
King Crimson - Lark's Tongues in Aspic (Album)
King Crimson - Starless and Bible Black (Track)
Supertramp - Crime of the Century (Album)
Infected Mushroom - Converting Vegetarians (Album)
Infected Mushroom - Legend of the Black Shawarma (Album)
Gorillaz - Plastic Beach (Album)
Massive Attack - Mezzanine (Album)
Fleetwood Mac - Rumors (Album)
Run the Jewels - Run the Jewels (Album)
The Prodigy - The Day is My Enemy (Album)
Tobacco - F****d Up Friends (Album)
Felt - Felt 2 (A Tribute to Lisa Bone) (Album)
NA Blur
NA Blur
Excellent pictures
Pros: Crystal Clear Sound,
Airy Presentation,
Build quality,
Great Cable
Cons: No detachable cable,
Missing some bass between 50-120 kHz
Alpha & Delta D6; Jazz sounds now better than before...

1. Introduction:

Alpha & Delta is a Singapore based brand that was founded of audiophiles with experience in the earphones retail industry. The D6 is the latest model of this company and there are also some few other models like AD01, D3, JAAP (wireless model) etc. that targets different users.


2. Disclaimer:

I would like to thank Alpha & Delta for providing me the Alpha & Delta D6 as a free of charge review sample. I am not affiliated with Alpha & Delta beyond this review and these words reflect my true, unaltered, opinions about the product.

3. Price & Warranty:

The MSRP price for the Alpha & Delta D6 is 95.00 USD and has a 3 Years Warranty.

Purchase Link:

4. Package and Accessories:

The Alpha & Delta D6 comes in a black card box with a transparent plastic front cover.

This box includes the following contents;

  • 1 x pair of ear guides
  • 1 x shirt clip
  • 1 x pair of foam tips
  • 9 x pairs of silicon ear tips
  • 1 x leather case
  • 1 x leather cable wrap
The silicone ear tips included in the box are comfortable and the foam tips are a nice addition.

20180319_233213.jpg 20180319_230942.jpg

The box includes a leather wrap and leather case that are looking very nice and are quite useful. There is also 1 pair of Ear-Guide and a shirt clip that is also a nice addition.


5. Design, Build Quality and Fit:

The Alpha & Delta D6 is a very well made IEM with a bullet-style metal shell, which has a glossy gunmetal painting. At the back of the monitor are the AD (Alpha & Delta) logo and the HDSS (High Definition Sound Technology) printing. On the top and on the nozzle are two holes that serve as bass vent. The nozzle of the monitor is not angled and has a fine black filter.

20180319_231352.jpg 20180319_231858.jpg

The D6 is lightweight, fits comfortably in my ear and has an above average isolation.

The Alpha & Delta D6 has a non-detachable cable, which in my opinion one of the best in the market, especially for a IEM with a price of 95 USD. Alpha & Delta decided to use a wonderful looking 8 core Silver Plated Copper (SPC) cable, instead of a regular 4 core design. This ensures, according to Alpha & Delta, that the earphone continues to work, even if one of the cables breaks.


The D6 is reinforced at the y-split and at the earphone's housing. Moreover, the vulnerable 3.5mm jack is protected by a spring to ensure it can withstand any impact.



6. Specifications:

  • Driver Unit : 10mm dynamic driver
  • Impedance : 16 ohm
  • Rated power : 1mW
  • Frequency Response : 10 Hz- 40 Khz
  • Sensitivity : 105 +/- db/ mW
  • Cable : 1.2m silver plated copper cable (each core contains 22X 0.05 silver plated copper wires)
  • Plug : 3.5mm Gold Plated Plug

a. About HDSS High Definition Sound Technology:

Speakers create sound through vibration. Due to the small enclosure, the reflected sound waves can distort our music by interfering with the sound waves entering our ears. HDSS technology removes these reflected waves to ensure crystal clear sound. The removal of reflected waves also allows speakers to disperse sound coherently, allowing for a naturally projected sound stage.

b. About Dual Chamber Acoustic Design:

The dual chamber acoustic design redirects reflected sound waves into a uniquely designed second chamber which absorbs these sound waves. This reduces distortion and improves the clarity and soundstage of the earphones.


7. Albums & tracks used for this review:

  • Saskia Bruin – The Look of Love (DSF)
  • Diana Krall - So Wonderful (DSF)
  • Aretha Franklin – I Say a Little Prayer (Apple Music)
  • Melody Gardot – Who Will Comfort Me (Flac 16bit/44kHz)
  • LP (Laura Pergolizzi) – Lost On You “Live at Harvard and Stone” (Tidal Hi-Fi)
  • Mile Davis – Kind of Blue Album (Tidal Hi-fi)
  • George Michael – Older Album (Apple Music)
  • Dire Straits – Money For Nothing (DSF)
  • Emmanuel Pahud (Claude Debussy) – Syrinx (Apple Music)
  • Otto Liebert & Luna Negra – Up Close “Album” (DSF) – Binaural Recording
  • Alboran Trio – Autumn Mist (Tidal Hi-Fi)
  • GoGo Penguin – Fanfares (Tidal Hi-Fi)
  • Opeth – Damnation (Tidal Hi-Fi)
  • Megadeth – Sweating Bullets (Flac 16bit/44kHz)
  • Daft Punk – Get Lucky (Flac 24bit/192kHz)
  • Future Heroes – Another World (Tidal Hi-fi)
  • Michael Jackson - Billie Jean (DSF)

8. Sources used for this review:

  • IEM : Alpha&Delta D6, Pinnacle P2, TFZ Series 4
  • DAP/DAC : Cayin N5II, HiBy R6, Chord Mojo, Audirect Whistle


9. The Sound:

I am of the sort of people that believes in burn-in and this review is written after 100 hours. I have used the stock silicone ear tips (soft ones) that are included to the package.


I was very surprised when I heard the Alpha & Delta D6 for the first time, because it was not a typical fun sounding IEM like many others in this price range. The D6 has a fairly neutral tuning with a tonality that is slightly on the thinner and colder side.


The Alpha & Delta D6 sound very controlled at the sub-bass department. It doesn’t reach to the lowest register but has otherwise a pretty good clarity and extension.

There is missing some body in the bass department between 50 – 120 kHz that gives normally warmth and fullness to the sound. Especial electronic music types such as trance, edm, etc. which are mostly based on artificially generated sounds are particularly affected by this tuning. But luckily, the D6 responds very well to equalizing and you can boost it anytime.

The bass characteristic is suitable for classic, jazz, acoustic songs with live recorded instruments.

The midrange of the D6 is impressive with its high level of clarity. I didn't expect such a detail level and crispness form an IEM in this price league. It sounds smooth, detailed and well placed and the separation of instruments is in a very good level.

I have tested some songs with complex instrument passages like GoGo Penguin’s – Fanfares where are many instrument playing at the background at the same time and the Alpha & Delta D6 sounded pretty controlled.

Both male vocals sounding quite realistic, but what really shines are female vocals like Melody Gardot and Laura Pergolizzi that are sounding clean and crisp with the D6.

There was a bit stress in the upper midrange at the very beginning, but after some burn-in and right tips selection, it was almost gone.

The treble range of the Alpha &Delta D6 sounds clear, crisp and well extended, without to be affected by sibilance. This was not the case at the very beginning; there was some sibilance for the first 10-15 hours that has gone after the next 50 hours.

Notes are precise and accurate and the overall tonal balance is well done. Genres like classic, jazz, acoustic are sounding very life like and precise. The D6 did a good job while presenting Alboran Trio’s - Autumn Mist that sounded very accurate and lifelike.


Soundstage and Imaging:

One of the strengths of the Alpha&Delta D6 is the soundstage presentation, which sounds wide and fairly deep, that has also an excellent imaging and instrument placement for this price category.


10. Comparison:

Vs. Mee Audio Pinnacle P2:

The Pinnacle P2 has a V-shaped sound signature with a consumer friendly tuning. The Alpha&Delta D6 on the other hand has a quite analytic sound tuning, which is suitable for critical listening.

The Pinnacle P2 has more sub-bass; especially bass quantity between 50 – 120 kHz, but is missing some definition. The Pinnacle P2 has the same amount of mid-bass impact with nearly the same resolution that the D6 has.

The midrange on the D6 sounds clearer and airier compared to the warmer and fuller tuning of the Pinnacle P2. Both IEM’s have a nice instrument presentation while the Pinnacle P2 is missing some speed in passages with high instrument density. Male and female vocals sounding a bit more natural and crisp due the brighter tuning of the Alpha&Delta D6.

The Alpha&Delta D6 is a treble centric IEM, which sounds overall brighter with more sparkle and air on the top end. The treble and upper treble area of the Pinnacle P2 has a more even tuning, which results to a more balanced presentation. The Alpha&Delta D6 has slightly more detail retrieval and sounds also more refined.

The Pinnacle P2 does its job in terms of soundstage, but the Alpha&Delta D6 is a step forward and has a wider and deeper soundstage presentation, where instruments have more space in complex passages. The Alpha&Delta D6 sounds also more precise in imaging and instrument placement.

Vs. TFZ Series 4:

The TFZ Series 4 has the same V shaped sound tuning like the Pinnacle P2 with a overall warmer sound tuning with higher bass presence. The D6 in the other hand is a treble centric IEM with an analytical tuning.

The TFZ Series 4 has a nice bass presentation in the subbass and bass department with a pretty nice impact that makes it too a better option for electronic music genres like techno, trance and edm. The D6 on the other hand has the better bass extension, speed and definition that make it very suitable for live recorded songs like jazz, blues, acoustic genres.

Both male and female vocals sounding fuller with the TFZ Series 4, but Alpha&Delta D6 has additional sparkle and transparency in the midrange department, which makes the listening of female vocals like Laura Pergolizzi and Saskia Bruin more exiting. The instrument reproduction of both IEM’s is quite good, but some string instruments like guitars have a more lifelike presentation with the D6.

TFZ Series 4 sounds pretty good in the treble range with its soft and non aggressive tuning. The Alpha & Delta D6 has additional sparkle and extension in the treble department with overall extra resolution. The upper treble range of the TFZ Series 4 is well controlled but is missing some fine definition compared to the D6.

TFZ and Alpha&Delta are nearly similar in soundstage performance but the D6 has additional wideness with better overall imaging and instrument separation.

11. Conclusion:

The Alpha & Delta D6 is an IEM that is focusing on clarity and soundstage with its treble centric presentation that is wonderful done. It has also a solid build quality with a great accessories package that makes the Alpha & Delta D6 worth’s every penny.

12. Summary (plus and minus):

+ Crystal Clear Sound
+ Airy Presentation
+ Build quality
+ Great Cable

- No detachable cable
- Missing some bass between 50-120 kHz


This review was originally posted on "Moonstar Reviews" :
  • Like
Reactions: H T T
Pros: Build quality, clean sound
Cons: Slight metallic tone, not a lot of body
Firstly I would like to thank Alpha & Delta for sending me this sample for review, these received over 100hrs of burn-in before writing.

*disclaimer: This sample was provided for the purpose of writing a review, no incentive was given to write a favourable review. All opinions expressed are my own subjective findings.

Gear Used: Audio Opus #2 / Hidizs AP200 / Objective 2 amp > D6


Tech Specs:

  • Driver unit: 10mm dynamic driver
  • Impedance: 16 ohm
  • Rated power: 1mW
  • Frequency Response: 10 Hz- 40 Khz
  • Speaker Sensitivity: 105 +/- db/ mW
  • Cord Length: 1.2m silver plated copper cable (each core contains 22X 0.05 silver plated copper wires)
  • Plug: 3.5 mm
  • MSRP: $99

Packaging, Build Quality and Accessories:
The D6 come in a plastic and card box, it is very simple and aesthetically pleasing with specs on the back. You simply cut through 2 tape rings to remove the front plastic and you are in to the packaging. You can see the IEM’s through the front plastic packaging, they are held in a foam insert. The packaging is minimalistic, which I quite like. The accessories are held in the carry case which you will find in foam insert too.

Build quality is simply superb on these, they come with a 3-year warranty, it shows Alpha & Delta are confident about the build. The housings are metal, the cable has excellent strain relief and is an 8-core silver plated copper cable. The cable uses a square braid, it’s substantial yet supple and terminates in a right angled jack. Overall I cannot fault the build quality of the D6.


Accessory wise these come with a good array of tips, you get S, M and L in 3 different types of silicone single flange tips, along with a pair of M foam tips. You gear ear guides, a shirt clip, a leather carry case and a leather cable wrap. Overall a really good set of tips and accessories for the price.

Comfort, Isolation, Cable noise and Driver flex:
The D6 are quite a conventional shape, and should fit most ear shapes quite easily. I found them to fit best when you loop the cable up and over your ear, I didn’t need the ear guides to wear them like this comfortably. They fit with a medium depth insertion well, it can sometimes be hard to tell if you have a good seal though as they do not isolate very well. Overall the fit is secure and comfortable, I had no issues.


Isolation is not their strong point, the IEM’s are heavily vented which allows a lot of outside noise in, these would not be my first choice if you are planning to use them in noisy environments. However if you want to maintain some sort of awareness when out and about, they are perfect.

Cable noise is present when worn cable down, so the shirt clip should help with this, otherwise it is not an issue when worn over the ear.

Driver flex is not an issue these have.


Split into the usual categories with a conclusion at the end.

Lows: The D6 take a more neutral approach to bass quantity, offering up a very tight and precise presentation that some may find a little lacking. The lows can still extend deep, but they are not boosted in volume. Kicks have good body behind them, they are quick and the transient response is very good. These would not be my first choice for EDM music, or modern pop, but tracks played on real instruments work very well. I think a tad more presence down low would suit some, and they do respond very well to EQ. Overall these are on the more neutral side of sound down low, and are not for those who enjoy a fuller bodied sound.

Mids: The midrange is incredibly clear on the D6, subtle details really shine through and they are not influenced by the lows. The midrange is slightly forward and the detail coming through really is impressive, both male and female vocals come across with equal energy and clarity, the midrange is quite linear and there is very little sibilance to be detected in the upper midrange. The transition to the treble is smooth; the midrange lends its hand to rock music very well due to the clarity and also power behind guitars.

Highs: The highs are very smooth on these, they are well presented with good energy and extension but they never become harsh. The highs are articulate injecting air and shimmer up top but without overdoing it. The only thing that is possibly a bit out up top is the timbre, the overall sound of the D6 is not one that is organic and natural, it leans towards a brighter more analytical sound and there is maybe a hint of metallic tone to it. They are a little colder sounding but without sounding harsh and fatiguing, they are quick and airy.

The soundstage of the D6 is one of its strengths, the soundstage is much wider than most fully sealed IEM’s, I am guessing the venting helps here. The soundstage is wide with excellent imaging and placement too. There is superb separation of each instrument, and each instrument expertly fills its place within the soundstage.


Conclusion: The D6 is not going to appeal to bass-heads, it is not one for modern pop, EDM and hip-hop/rap. But if you listen to rock, metal, jazz and music played on real instruments these come into their own. The slightly cool tonality expertly reveals micro-details with ease, and they have excellent transient response playing well with complex metal tracks. The midrange cannot be beaten at this price if you are looking for realism and detail. I can overlook the slight deficiency in body down low when the midrange is this good. So if you like a more detail oriented IEM, take a look into these as they definitely punch above their price point.

Sound Perfection Rating: 8/10 (a slight metallic tinge up top, but incredible detail and linearity across the board make these superb)
  • Like
Reactions: H T T and hqssui
Pros: Sub-Bass Extension, Clear Midrange, Crisp Treble.
Cons: Detachable cable would be nice.

Alpha & Delta is a Singapore brand that features a lineup consisting of AD01, D2 and JAAP that targets different users. The D6 is a newly released iem that utilises their own technology, HDSS high definition. I would like to thank Lend Me Ur Ears for this opportunity to review their latest iem, Alpha & Delta D6. At the moment, you can purchase the D6 from .


  • Driver unit: 10mm dynamic driver
  • Impedance: 16 ohm
  • Rated power: 1mW
  • Frequency Response: 10 Hz – 40 Khz
  • Speaker Sensitivity: 1055 +/- db/ mW
  • Cord Length: 1.2m silver plated copper cable (each core contains 22X 0.05 silver plated copper wires)
Unboxing & Accessories

The D6 comes in a black package with a transparent cover. At the front of the cover, it shows the description, brand name and model name. After removing the cover, there is a leather case which contains 1 pair of ear guides, 1 shirt clip, 3 packs of tips and 1 leather cable wrap. There is an instruction manual too. The overall packaging is nice.

IEM Build & Design

The D6 has a glossy gunmetal faceplate with the Alpha and Delta initials printed on it, “AD”. Below the initials, there is the HDSS technology name printed. It is in a different shade so it will contrast with the gunmetal colour. There is a vent at the top of the iem and near the nozzle. The iem has a circular shell with circular indents. It has a straight nozzle with a soft mesh for earwax prevention. The material used to make the D6 is aluminium. The iem has no detachable cable. The D6 is rather light weight and its design is quite simple. Overall, it is constructed well and fits in my ear comfortably.

Cable Build & Design

The cable is 8 core braided and there is strain relief on each side. On the strain relief, there is a L & R marking on the inside of the strain relief to differentiate between left and right. There is no memory wire area. Moving on to the y-splitter, it is circular and the housing is gunmetal in colour. There is strain relief at both ends. Lastly, the jack is 3.5mm right angled gold plated. The housing that extends from spring loaded strain relief is gun metal in colour while the housing that extends to the gold plated jack is matte black in colour. It is a good cable with a robust build and visual appeal.

Sound Analysis


The D6 has an excellent sub-bass extension with a great punch to it. The sub-bass extends itself well and I am able to feel the depth. Rumble is speedy and it is presented in the most engaging way. The bass decay is agile and each bass note keeps coming which helps to improve the overall dynamics. There is no lacking in body too and this does not compromise on the nature of it. Presentation is rather clean. There is a good mid-bass slam which helps to give the sound an extra punch. Bass is generally impactful and there is a smooth transition from the lows to the lower midrange.


The midrange on the D6 is fun sounding. I feel there is a good quantity in the midrange. For the lower mids, it is slightly boosted by the lows. It is not hollow and male vocals are presented in a natural way. The upper mids is quite forward and female vocals shine with definition. There is crisp and I feel the quantity is sufficient for vocals to have a bite. Resolution on the D6 is good and the midrange operates in a clean and lively manner.


The treble is extended well with a good mastery. It is tight and the finesse is there. There is good quantity to it with a slight sparkle for a punch. There is no sibilance and harshness. Although it is not the smooth kind of treble, it retains the liveliness with a very tight control so it will not be expressed as shouty. There is a good level of details retrieval and the amount of air rendered gives a lot of space so it does not sound congested.


The D6 has a good width in its stage so you will get an open feeling. The width aids in the positioning of instruments and vocals. The depth is not close in and there is a good 3D feel with vocals intimacy being retained. There is a good natural expansion.


Alpha & Delta D6 vs TFZ Exclusive King

The D6 has less sub-bass quantity but its extension is greater than the King. It stretches deeper and the sub-bass reproduction is clean. Bass articulation is very similar. The D6 has more speed than the King and there is a better expression in the rumble. Rumble is pacey and the overall sound is more exciting. The mid-bass quantity on the King is more and there is more slam. In terms of the overall bass, the D6 is more exciting due to its quick decay. The lower mids on the King has more quantity than the D6. In terms of upper mids, I find the D6 to be more forward and there is extra definition and crisp. There is a good bite coupled with intimacy of female vocals. Next, the treble on both has similar air and D6 being the more energetic one, has a good sparkle. Treble articulation on the D6 is more precise. Details retrieval on both is very similar. In terms of soundstage, I find both of them to have an equal width and the D6 has an added depth for a more open feel. Positioning of instruments and vocals are better on the D6. Resolution of both is very similar but D6 has the edge due to its speedy decay.

Alpha & Delta D6 vs Mee Audio Pinnacle P2

The P2 has more sub-bass quantity than the D6 and extension on both is very similar. The P2 has a rumble that is as quick as the D6. Bass decay on both is similar. I find the bass articulation on the D6 to be more precise. The mid-bass quantity on the D6 is slightly more with more slam. Overall dynamics increase for a more engaging listen. Transition from the lows to the lower mids are quite smooth on both. Lower mids on the D6 has similar body as the Pinnacle P2. Male vocals are being expressed without sounding hollow. The upper mids on the P2 is more forward and there is a slight crisp to it. In the treble department, D6 has more air rendered with sparkle. There is more bite on the D6. Presentation on both is clean with a good level of details retrieval. The D6 has more stage width and depth. The positioning of instruments and vocals is more accurate on the D6. Resolution on the D6 is more refined.

Alpha & Delta D6 vs Kinera H3

The H3 has more sub-bass quantity but it lacks the extension D6 has. The bass impact on both is present with the D6 stretching more deeply. Bass decay of H3 is slightly faster with a quick rumble. The bass note on the D6 does not hit very hard but it is being articulated with authority and control. The bass texture on the D6 is slightly smoother. For mid-bass, the D6 has more slam for increased dynamics. The lower mids on the D6 has more quantity than the H3 while the H3 upper mids is more forward. Male vocals is definitely better expressed on the D6. For female vocals, I feel the D6 has a good mastery in it while the H3 does not control it as well. In terms of treble, the D6 has a good treble body and extension. It has similar amount of air as the H3. Moving on to the soundstage, D6 has the better width while H3 has the better depth. Resolution level is very close.


The D6 is a detailed bright sounding iem that has a good mastery at the top end. Not only does it has finesse in its treble presentation, its bass note has a very good impact which helps to raise the overall dynamics. Coupled with a 8 core cable and a spring loaded design for the jack’s strain relief, the D6 has a combination of excellent build design and engaging sound signature.

For more reviews, visit .
  • Like
Reactions: B9Scrambler
Pros: Best-in-class durability, transparent and detailed sound, natural and cohesive signature, excellent accessories, visually attractive design, metal housings, 8-core SPC cable
Cons: Occasional sharpness
Alpha and Delta D6 Review: Built Like a Tank
Alpha and Delta is a Singapore-based company run by audiophiles. They have been designing and selling IEMs for a good amount of time now, with their bread and butter being durability. They’ve consistently released IEMs that outlast their competitors. This year they have decided to up the ante and release a premium IEM that doesn’t compromise on their values of durability, the D6.

You can find the D6 for sale here, on Alpha and Delta’s official website, for $95.

Disclaimer: This unit was provided to me free of charge for review purposes. I am not affiliated with Alpha and Delta beyond this review. These words reflect my true, unaltered, opinion about the product.

Preference and Bias: Before reading a review, it is worth mentioning that there is no way for a reviewer to objectively pass judgment on the enjoyability of a product: such a thing is inherently subjective. Therefore, I find it necessary for you to read and understand what I take a natural liking to and how that might affect my rating of a product.

My ideal sound signature would be an extended sub-bass with a leveled, but textured, mid-bass. The mids should be slightly less pronounced than the treble, but still ahead of the bass. I prefer a more bright upper range.

Source: The D6 was powered like so:

HTC U11 -> USB-C adapter -> earphones


Hidizs AP100 3.5mm out -> FiiO A5 3.5mm out -> earphones


HiFiMAN SuperMini -> earphones


PC optical out -> HiFiMe SPDIF 9018 Sabre DAC 3.5mm out -> earphones

All music was served as MP3 @320Kbps or as FLAC.

Sound Signature
Initial Impressions:

It’s bright. In fact, it’s the first IEM I have reviewed in a long time that prioritizes the treble this much. It can effectively be considered a reverse-L-shaped IEM as the treble comes out in front, followed by the mids which are almost evenly matched with the bass.

Treble: Songs used: In One Ear, Midnight City, Outlands, Some Might Say, Satisfy

An IEM such as the D6 often struggles to find the best balance between enhanced clarity and not becoming sharp and overly hot. Alpha and Delta are clearly aware of this and took certain steps to mitigate any potential sharpness that could arise from a tuning as aggressive as the reverse-L. They did an admirable job in my books: nearly every single song I listened to had a well-extended, incredibly airy presentation. I’d wager that the treble curve on this is quite similar to that of the Accutone Pisces BA, a personal favorite of mine.

Most of the D6’s treble performance is predicated on how well the song you are listening to is mastered. Does it have lots of compression? Is it participating in the Loudness Wars? If so, the D6 will respond quite poorly. But should it be mastered by someone with even moderate skill, there won’t be any issues.

Cage The Elephant seems to have used producers with adequate skill since the treble of In One Ear was clean, airy, and quick. Each individual hit of the cymbals and high-hats was clear and fully articulated. Same goes for Midnight City. The synths melded together well and remained clear throughout the entirety of the song.

Treble detail retrieval is pretty damn good and is competitive with IEMs that have BA drivers in them. I am thoroughly impressed with just how clear the tiny parts of each song come through. For example, the background of Some Might Say is filled with subtle percussion instrumentation, much of which gets melted together on lesser IEMs. The D6 delivers a clean articulation these sounds.

That said, there were occasions where I needed to turn the volume down on the D6 to avoid discomfort due to sharpness. Satisfy was definitely sibilant and hard to listen to. I’d imagine that this hotness comes from some misbehavior in the 4KHz–6KHz range.

Mids: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Dreams

The D6’s mids are pretty even and have a slight rise towards the upper mids, likely to blend it with the treble. While they don’t quite have the edge of clarity that the treble has, they win terms of timbre. The D6 is almost completely transparent. It gets out of the way in a similar manner to the Earnine EN120, an IEM with the best transparency I’ve ever heard in the mids.

I am a particular fan of the tonality the D6 gives electric guitars. The crunch on the lead guitar of Flagpole Sitta is satisfying. This property translates nicely to I Am The Highway, which benefits similarly.

Speaking of which, the vocals of I Am The Highway were a pleasure to listen to. Their weight was a little light for me, but they were nimble and very clear nonetheless. Female vocals definitely take the lead here, if by only a small amount.

Bass: Songs used: Moth, Gold Dust, In For The Kill (Skream Remix), War Pigs (Celldweller Remix)

The D6’s bass is clearly tuned to suite songs like Moth over those like Gold Dust. Bass tonality is fairly linear, but there is still a small mid-bass hump. It isn’t too emphasized and lies in-line with the mids for the most part. This tuning defies the traditional consumer V-shape making for a more detail-oriented take on the lower-mids and bass. It definitely does pay off: bass guitars (which are usually mixed pretty far into the background) maintain their solidity and tonality consistently and do not get blurred out or pushed beyond audibility.

So then are electronic songs a lost cause? Not exactly. If the songs you are trying to listen to are mastered well you will still get a reasonably aggressive bass line: I could definitely make out some mild rumble in Gold Dust, though it is certainly nowhere where it would need to be to be considered a basshead IEM. War Pigs fared similarly, though it did feel a bit shallow without the big impact bassier IEMs tend to afford it.

Bass extension is pretty good too, with the D6 managing to push fairly low and keep up fairly well with the bass line of In For The Kill. While it did tend to lose some solidity at the lowest frequencies in the song, it never felt messy or overblown. The lower-mids retained their independence and were never smothered.

Packaging / Unboxing

The D6’s packaging is minimalist but effective. While it could use a visual overhaul (replacing the plastic front face with some thick cardboard), I think that it doesn’t look too bad. It just doesn’t have that premium feel that it should.

Construction Quality

The D6 uses a “bullet” shell style. It makes use of a metal alloy for the driver housings. They’re coated in a gun-metal finish. It is surprisingly light. Based on that and the hardness of the housing I think that Alpha and Delta used a zinc-based alloy.

The nozzle is appropriately long and has a well-shaped lip. In the mouth of the nozzle rests a metal mesh that does a good job keeping out debris.

The cable is an 8-core SPC cable. 8-cores means that there is a certain level of redundancy within the cable that allows some of the cores to break while still allowing it to transmit the audio signal correctly. Having more cores also means that the cable can better resist pull-and-push forces.

The D6 has great stress relief. It is touted as designed to last, and I can definitely see that in the design of the shells. The stress relievers are functionally similar to the ones used by the AAW Q, despite their vastly different appearances. This lends me a lot of confidence in the D6’s lifespan. After all, it would be a darn shame for something of this price to break because of a bad cable.

The stress relief on the Y-splitter is also quite good. Between the outer plastic layer and the cable itself lies some shrink-wrap plastic. This plastic helps even out the force being applied to the cable by the stress relief; a very important component of durable braided cables.

The D6’s cable is terminated via a TRS 3.5mm jack. It had an additional level of stress relief as it makes use of a spring. Given that the 3.5mm jack is usually the first place that the cable beings to break, this choice was wise.

Overall, I give the D6 a near perfect score in terms of durability. There are no apparent compromises of flaws in design. The plastic is all well finished with, the metal is hard and secure, and the cable is tough. No complaints anywhere.


The D6 has some reasonably wide shells, but they don’t impact my comfort at all. That being said, those with smaller ears may have a hard time getting the D6 to seal without using foam ear tips.

I had no comfort issues while listening to the D6 for multiple hours, nor did I have any problems with it while being active with it. While I do not recommend using an IEM like this at the gym, it can be done with relative safety.

Alpha and Delta stocked the D6 well with accessories. Inside the box you will find:

  • 1x leather carrying case
  • 1x pair of removable earguides
  • 3x pairs of solid-core eartips
  • 3x pairs of smooth-core eartips
  • 2x extra pairs of standard silicone eartips
  • 1x pair of foam eartips
  • 1x leather cable clip
I really like the accessories that A&D chose to include. None of them feel cheap at all, and each one looks like it was carefully chosen to work well with the D6. I am especially a fan of the leather carrying case and cable clip. They are pretty well made are unique among the IEMs I’ve tested.

The Alpha and Delta D6 features attractive design, extremely durable construction, and a detail-oriented sound signature. The D6’s build makes no compromises, and it definitely shows. If Alpha and Delta can revise it such that it eliminates the hotness in the treble, they’ll have a huge winner. So if you’re looking for an IEM that has boosted treble, premium looks, and very high durability, but don’t mind the occasional sharpness, the D6 should definitely be on your radar. Thanks For Reading!
Nice review, but my experience is slightly different than yours. I don't hear the sharpness you mention, but I might have a hearing dip at that frequency. I find the D6 to have amazing soundstage which differs from your review.

I love my D6. It is my favorite IEM for classical and acoustic music.
Pros: Clarity and resolution
Comfortable and well constructed
Included accessories
Cons: Non-detachable cable

Lend Me UR ears is a Singapore based retailer of personal audio equipment. The store was opened in December 2011 with a goal to “bring quality audio products to the masses and providing good customer service in the process”. They offer free international shipping and international warranty for all items purchased. LMUE also develops their own earphone brand "Alpha & Delta".

A little over a year ago in September 2016 I reviewed the Alpha & Delta D2 (review here). My wife has been using it as her daily driver ever since and it's still in perfect condition - testament to its durability and build quality. Lend Me UR ears has long been developing a new line of IEMs and one of them, the Alpha & Delta D6 is finally ready for the people. The D6 has a clear, resolving and balanced sound that's not often found it its price range. The D6 boasts some impressive features including a Dual Air Chamber acoustic design, licensed HDSS high definition technology and Hi-res audio certified drivers. But how does that relate to the end user experience? Let's see if we can find out.


This sample was provided for the purpose of an honest review. I'm not affiliated with the company and all observations and opinions here are my own, based on my experience with the product.

The Alpha & Delta D6 is available from the Lend Me UR ears store: (price in Singapore dollars).

To buy in US dollars you can go to the official Alpha & Delta webstore here:

  • Driver unit: 10mm dynamic driver
  • Impedance: 16 ohm
  • Rated power: 1mW
  • Frequency Response: 10 Hz- 40 Khz
  • Speaker Sensitivity: 105 +/- db/ mW
  • Cord Length: 1.2m silver plated copper cable (each core contains 22X 0.05 silver plated copper wires)
  • Plug: 3.5 mm
Package and accessories
*Note this is a pre-production model so there was no packaging included. Here is a look at the accessories that will be included with the retail version:
  • 1 pair of ear guides
  • 1 shirt clip
  • 1 pair of foam tips
  • 9 pairs of silcone ear tips
  • 1 leather case
  • 1 leather cable wrap

Build, comfort and isolation
The D6 sports metal housings in a polished, gunmetal gray color. They are of the common cylindrical shape type that is popular in IEMs with a couple of rings toward the back that serve to give the shells a more interesting appearance rather than having a plain and straight surface. On the rear of the shells is the Alpha & Delta branding and HDSS lettering. I would have liked to see the rear edge a little more rounded as it can sometimes press against the antihelix and cause hotspots. On the top of the shells towards the rear is a very pinhole sized vent/bass port and there's another at the base of the nozzle. The nozzles are of average length and width, making tip rolling easy and there's a distinct lip to hold the eartips securely. The D6 are very lightweight and look to be very durable and well built.


Onto the cable now and easily the nicest cable I've seen on a sub $100 IEM. The white, 8 core, silver-plated copper cable is deliciously thick from the plug to the Y-split. It feels fantastic and sturdy in the hand yet is really soft and supple, so it sits well and there's no bounciness to it. There's a metal Y-split made from the same metal as the housings and the same gunmetal gray color. The strain reliefs from top to bottom are fantastic. There's a small bump on the left side where it attaches to the housings to denote the Left side. The cable terminates in an L-shaped plug, again using the same metal as the housings. There's also a substantial spring style strain relief here, similar to what you find on some Trinity Audio IEMs. It works extremely well but I feel it could have been made half as long and still be just as effective. The only downside to this cable in my opinion is that it is non-detachable but it really feels built to last and as is absolutely gorgeous.

DSC_0344.jpg DSC_0274.jpg DSC_0276.jpg

Comfort is good, as is the norm for this shape in an IEM and the light weight of the shells doesn't cause any burden on the ears. I found noise isolation to be about average and suitable for most situations.

About HDSS high definition Sound Technology

Real-time crystal clear sound without distortion

Speakers create sound through vibration. Due to the small enclosure, the reflected sound waves can distort our music by interfering with the sound waves entering our ears. HDSS technology removes these reflected waves to ensure crystal clear sound.

Detailed 3 dimensional sound reproduction

The removal of reflected waves also allows speakers to disperse sound coherently, allowing for a naturally projected sound stage.

About Dual Chamber Accoustic Design

The dual chamber accoustic design redirects reflected sound waves into a uniquely designed second chamber which absorbs these sound waves. This reduces distortion and improves the clarity and soundstage of the earphones.

Built like a tank- 3 years warranty

The weakness of any pair of earphones lies in its wires. Majority of the earphones uses 4 core cable. Once breakage occurs in one of the cables, the earphones cease to function. Many earphones also do not come with sufficient strain reliefs to reinforce vulnerable areas such as the 3.5mm jack.

In response, the D6 reinforces the 3.5mm jack with a spring loaded design. Furthermore, D6 uses an 8 core silver plated copper cable to ensure extra durability. Thus, even if wire breaks, the remaining cores will ensure the continued functionality of the earphones.

This is a very different beast from the A&D D2. It's more balanced and resolving across the board. The bass has more texture and definition, vocals and midrange are clearer and treble has more presence and extension. There isn't any single area where the D6 shines, it's more of a goodness across the board type of IEM. Sound is balanced and leaning slightly towards bright.

While the D6's sub-bass has great extension it doesn't carry a lot of weight, keeping in line with its balanced approach. When it comes to mid-bass the D6 has lovely texture and definition but is consistent with the sub-bass in its mature levels. There's enough punch there to drive music and a natural, fairly fast decay that brings realism and at the same time great control. This is not an IEM for the bassheads out there but for those looking for a more even tonal presentation..

Midrange is very tidy, its instrument separation impressive and level of clarity above average. Vocals are sweet, particularly for female vocals that get a little boost and are a real treat. Male vocals also get some love with a little weight carried over from the upper bass to give them enough richness to avoid sounding thin, yet at the same time don't sound colored. Lovers of classical music should appreciate the timbre and clarity of the D6's midrange with its slight upper midrange boost - Beethoven's String Quartets by the Emerson String Quartet sounds fantastic with these. Don't think these are limited to the classics though - "Down" by Run the Jewels sounds energetic with the vocals still managing to pop despite the tracks heavy bass.

Treble is nothing short of excellent on the Alpha & Delta D6 for something in its price range. The extension is fantastic, providing plenty of air and detail. It's nimble and energetic but never strident or piercing. The sheen of cymbals and bells is really nice, the way they ring before fading into the distance. There's enough sharpness to grab your attention but it eases up before it becomes uncomfortable and its far reaching nature adds greatly to the dynamic range. It's clean, it's nimble and it pops.

Soundstage here is very clean with a fair amount of width and depth. There's plenty of space between instruments which are positioned accurately enough to let you know just where they're situated. Stereo separation is another strong point and imaging is above average, the overall impression is one of clarity and detail.



TFZ Series 4 ($99 USD)

The most notable difference here is the bass, with the series 4 having a much more pronounced mid-bass. It's a really punchy and impactful bass which actually sounds a bit over the top after listening to the D6 for several consecutive days. The jump between the bass and midrange is more noticeable on the Series 4 - that meaty bass doesn't carry over into the lower mids, making them sound a little thin. The TFZ's thinner, boosted upper midrange gives less distinction between upper mids and treble making the top end sound less separated and lacking the separation of the D6. While the Series 4 sounds more typically V-shaped the D6's rise from low to high is more linear without the associated peaks found in the Series 4. The D6 has a more defined soundstage with superior imaging.

Toneking 9 Tail ($125 USD)

The TNT has more bass presence but it lacks the texture and definition of the D6. Both these IEMs are fairly balanced but where the TNT puts more emphasis on bass the D6 instead boosts the upper midrange. While the D6 has a bright personality the TNT is a smoother and more relaxed listen. Both of these IEMs have good detail retrieval but the D6 has more clarity in the midrange that gives it an edge in instrument separation. Treble on both is light and airy, the TNT being a little smoother in this area and soundstage is equally impressive on both with the D6 having a slight advantage in imaging.


The Alpha & Delta D6 was certainly not what I was expecting after my experience with the D2. The D6 has a much more refined and mature tuning and is definitely a big step up in terms of technical performance.

With its mature tuning the D6 is a more serious offering from A&D that aims more towards transparency and resolution compared to the D2's fun and relaxed approach. The D6 impresses not only with its clarity and detail but also with soundstage and imaging. Anyone looking for something more balanced and less V-shaped than the typical offerings in the $100 range should take a look at the Alpha & Delta D6. It offers a solid build and great sound and comes with a very impressive 3-year warranty.