HUM Pristine Dual BA IEM

HUM Pristine earphones became for me one of the biggest surprises of 2016, so I've decided to gather my skills and create a review. HUM is pretty well known on the exUSSR market due to their Pervasion DAP, which gathered a group of fans of its unique sound. Meanwhile, other HUM's products (IEMs and cables) remained relatively unknown.


First of all, I'd like to thank HUM for providing me with a sample for review in exchange for my honest and unbiased opinion.

HUM came with all diligence to the creation of Pristine and results have turned out great regarding sound quality. But from the marketing point of view, it's hard to sell people IEMs with "just" two drivers. Modern buyers are spoiled with wild numbers of drivers in top-tier IEMs, and it's hard to judge by what you hear, and not by pure specs only. HUM Decided to do everything at the top level, so they've found perfect drivers, created uncompromising crossover using electrolytic capacitors and Vishay resistors. Internal wiring is made from top-level litz. Sockets are made by Amphenol, and so on, and so forth. Developers even used two different kinds of solder to obtain better sound. The crossover was calculated to have maximum coherence and minimize phase distortion.


In general, the developers have decided that it is better to use only two drivers but to use them to the full.

Accessories set is pretty basic. Earphones came in great genuine Pelican case, protecting them from all problems, inside you'll find IEMs themselves and cleaning tool. Pristine exists in two kinds, custom and universal, with universal you'll get three pairs of gray silicon tips. HUM rightly decided, that hi-end IEM users will have their own tips set. Also with Pristine you'll get great cable HUM CX-1, it's made from highest purity copper and costs $300 alone, so it's a great addition to this earphones. Cable is soft, but sturdy, probably, it's the best stock cable among all IEMs that I have.


Like other manufacturers, from HUM offers different color options and faceplate customization, but I believe that best option for pristine is transparent colorless acrylic so that you can see the internals of this IEMs. Inner details of this earphones look really pleasing: capacitor, drivers, internal wiring — all are neatly placed inside. Overall quality of the shells are close to perfection — no traces of dust or bubbles, typical to low-quality castings. The only decoration on my pair of Pristines is bright red company logo in faceplates.


Shells are surprisingly small, it's one of the pluses of having only two drivers, and thanks to a nicely rounded shape, IEMs fits nicely even for small ear owners. Sound isolation is a bit above average for universal version and noticeably better than average for customs, actually, as expected.


For listening, I've used following equipment.

• NuPrime DAC-10H and Resonessence Labs Concero HP as DAC and amplifier
• Apple MacBook Pro Retina 2013 with Fidelia as a source
• Lotoo PAW Gold, Fiio X7 and theBit OPUS#2 as portable players

My version is universal, so the sound of customs can be a bit different. Also, universal shells require more work to select proper tips and got the best fit. Before listening, I've burnt IEMs in for 96 hours. Usually, BA doesn't need such a long burn in, but this includes the electrolytic capacitor, so I decided to carry out the necessary formalities.


The overall presentation of Pristine corresponds their name: genuinely neutral IEMs with a bias on micro-details, but they avoid being too bright or harsh. These earphones created for "serious" music, with superb mastering and they require a good source. This neutral representation isn't for "mass market," so they can sound too neutral for some styles, but those, who are looking for maximum sound purity, will be satisfied.

Lows of Pristine are source-dependant. I didn't find any correlation, but with some DAPs, they have rolloff on sub-bass, while others drive this IEMs without any issues. I'll describe some pairings below. So, with "compatible" players, Pristine gives the nice amount of both sub and mid bass, which is fast and detailed. Of course, bass here isn't as weighty as in dynamic/hybrid models, it's more "armature" type of bass — a bit dry, fast, with excellent textures.

Mids of Pristine for me are close to absolute etalon of mids representation in IEM world. HUM's earphones manage to combine incongruous. They are very detailed, but they don't sound too thin and dry. They didn't go into nitpicking like many BAs do, so they are to some extent "forgiving" for not perfect recordings. These earphones are splendid in transmitting emotions and instrument's characters. So, it's a real pleasure to listen to "audiophilic" recordings with them. The imaginary stage is close to real in size, and it's spacious and 3-dimensional.


Treble a little brighter than in ordinary modern "average IEMs," primarily it's due to the excellent attacks and decays. Highs aren't sharp, at least if recordings are good, and your DAP can control treble. Everything in this range sounds fascinating, starting with light chimes of percussion, and ending with almost subtle overtones. So, Pristine can forgive some errors in recording's mids, but treble should be recorded perfectly.

The combination of a pretty high impedance and high sensitivity imposes some restrictions on the sources for this model. Players or amplifiers for them must be detailed to showcase strengths of this model. They should work well with high impedance and have little noise. Almost all high-end DAPs are a bit noisy with Pristine, but in most cases, this can be heard only in silence. Ironically, one of the best results showed Luxury & Precision L3, virtually noiseless with this model. The best result showed OPUS#2, noise is present but really quiet, bass goes very deep, and it sounds with power. Also, excellent pairings were Questyle QP1R and Fiio X7 with AM2. The reverse side of the coin - Lotoo Paw Gold and Cayin's players, in spite of all their advantages, Pristine isn't the best option for them.


Style-wise headphones tend to serious styles - classical, vocal, chamber music, live jazz. For sure, they are magnificent with many other styles, like metal and electronic music, but there are not so much of high-quality recordings that fully reveal this IEMs.


It's great that in an age of extensive development exist companies that can take a step back and think, "what we're going to get?". While others try to insert more transducers in small enclosures, HUM decided to achieve the maximum, using only two drivers, and they succeeded. Pristine - fully justifies its name, providing a rare purity and detailed sound.

 
Specifications
Manufacturer: Hum
Driver Type: Dual Balanced Armature (Knowles CI & ED)
Frequency Response: Unknown
Sensitivity: Unknown
Accessories: CX1 Cable, Pelican 1010 Hard case, Sleeves(small, medium, and large), ear wax removing tool
 
Summary
Design: Neat and beautiful inner structure
Finish: Superb
Tone: Warm overall, but depends on music
Soundstage: Average or less
Treble: Smooth and shattered
Midrange: Fast response. smooth and deep like creamy cheese. bold and clear vocals.
Bass: accurate response. Rich but not exaggerated. Low cut
Cable: Sound is changed a lot in case of switching cables. If you like the original sound, do not change the cables.
 
Balanced Armature drivers in high-end In-Ears.

1. The more drivers an in-ear has, the more benefits there are

 
Earphone manufacturers mount many BA(Balanced Armature) drivers in a small unit to improve the quality of earphones. It is way much better to output audio signal at whole frequency range separately through several drivers or sharing the drivers in terms of expression and resolution.
 
For this reason, manufacturers have made efforts to add more drivers in In-Ear Monitors. It hasn’t been long since IEMs have 3 to 4 drivers each sides. however, It is really surprising that IEMs have more than 10 drivers these days. Of course, the number of drivers is not the only criterion for evaluating IEM’s performance, but IEMs are often rated according to the number of drivers and the IEMs which have many drivers are called ‘high-end’. Therefore, the number of drivers are the touchstone of IEM’s performance and an important factor in determining the price.
 
Pristine

1. Dual Driver High-end In-Ear Monitor

 
HUM, based in Hongkong, launched custom IEM, Pristine. Pristine means ‘very clean’ and ‘primitive’. It launched custom version first, and universal version later. Pristine’s cables are detachable, and you can choose between MMCX or 2-pin connector. The one I used most for this review is universal and MMCX version. Accessories are a Pelican 1010 hard case attached to a faceplate with HUM’s logo on it, sleeves which comes in small, medium and large and earwax removing tools. In case of custom version, no sleeves with the package. Thus, more simple.
 
Pristine’s official price in Korea is $1475.26. Sounds like high-end IEM? However, It has only two BA drivers. You probably wonder about this, because there are a lot of high-end IEMs which have many drivers. This is closely connected with company’s development philosophy.
 
HUM
Humming, Less is more.
 
The word ‘HUM’ is from ‘humming’. Pervasion, a digital audio player introduce the company to audiophiles. Pervasion has dynamic sound and special line-out volume control knob, whose name is perfectly matched by its performance.
 
HUM, founded in 2015, launched only three products: Pervasion, Pristine and CX1(cables for Pristine). HUM said it focus on the product’s quality and performance rather than expand its line-up. You can see its slogan ‘Less is More’ in Pristine.
 
The most important thing is internal stability

1. Approach to Hi-Fi Audio with two drivers

 
The first thing you notice is wires inside the transparent bodies when you see Pristine. The wire is 99.99% stranded Litz copper. It is designed to reduce the skin effect and proximity effect losses in conductors used at frequencies up to about 1 MHz. It consists of many thin wire strands, individually insulated and twisted together. Although the wire is short because of the small bodies, Hum produce it with great care.
 
(* Skin effect is the tendency of an alternating electric current (AC) to become distributed within a conductor such that the current density is largest near the surface of the conductor, and decreases with greater depths in the conductor. Suppose you are eating spaghetti riding a roller coaster. You can find noodles in your face. Skin effect is like that.)
 
If you look around, you can find many components except for drivers. From film/laminated capacitor to resistance, finest components fill the inside to refine and deliver audio signal reliably. From a common sense point of view, those are a little excessive for only two drivers. However, HUM used biggest and finest components as much as they could, so the two drivers can provide the best performance. It’s like Hi-Fi speakers which use biggest and finest components as long as small enclosure permits. Pristine showed distinctive features with their effort to obtain quality.
 
(*The function of capacitor - A capacitor stores electrical energy in an electric field and then provide steady amount of energy. When drivers try to make sound, they need different energy. Capacitor provide right amount of energy when the drivers need it. Other benefits are fixing sharp signal.)
 
Design & Cable
 
Pristine’s shells are transparent. Except for HUM’s logo, There’s nothing. Nevertheless, The components and wires inside complete the design. The name of the cables is CX-1. Wires consist of the same material as Pistine’s. They are quite heavy and smooth, which provide comfortable fit and resistance to tangle even without ear guides. The cable is terminated with Oyaide’s solid right angle plug. The identical colors for indicating hot and cold is hidden inside. 2-pin connectors are engraved outside, and it’s neutral cable so that you can connect it to anywhere without changing Pristine’s signature sound.
 
Smooth and various sound

1. Listen to a variety of music to appreciate Pristine’s worth. It’s sensitive to sources, devices and background.

 
Pristine has smooth sound, and it is good long-term listening IEM. Hum have not said publicly, but Pristine has high sensitivity which is good for high performance without turning up the volume. This high sensitivity is disadvantage in listening through 배경이 어지러운 기기, but you can hear every bit of details if you use a device like AK380. Pristine is heavily dependent on songs and devices. You can hear great sound, or old and clogged sound depend on devices and songs. I recommend to use as many devices as possible.
 
Pristine’s sound is hard style to pin down. If you listen to bright music, it sounds bright and warm, but heavy and foglike sound in dark songs. It has heavy and huge volume in mid-high, sometimes could deel masking on vocal and clean and warm sound on instrumental. If you are interested in purchasing Pristine, listen to your existing music randomly before you buy it. It is always pleasant to rediscover some music which is left behind, and Pristine makes you can discover those.
 
High-resolution and special texture

1. Less is more

 
Pristine only has dual drivers, but features higher resolution such as IEM which has many drivers. It catches every bit of details and separate frequency band well with fast response. In fact, IEM which has more than 10 drivers might be better, but you can’t even imagine Pristine has dual driver by just listening through it. Hum haven’t said it publicly, but the two drivers completely make separate sound. The capacitor, resistance and wires inside work well together to make great sound. To tell the truth, the number of drivers is not the most important thing to make high resolution sound. Pristine teach you well-tuned drivers are the ones you need to consider first.
 
Deep Soundstage with reverberation

1. Reproduce soundstage without making any adjustments.

 
Pristine doesn’t have wide soundstage. It reproduce reverb and delay which added intentionally, but doesn’t extent the soundstage artificially. That means it shows wide soundstage widely and narrow soundstage narrowly. For listeners who want wide soundstage such as K3003, Pristine might satisfying. However, Pristine reproduce soft sound on the whole, like drinking a cup of café latte, and the reverberation is like the milk and coffee smells when you finished the latte.
 
High-mid

1. Clear and soft upper midrange

 
Pristine has the best midrange I have ever heard before. Fast, accurate, and soft. It also shows punchy sound and bold voice, which means highest quality you can get from earphones. It even feels like listening from high sensitivity speakers with really special sound texture. Soft but husky. This stands out at treble, attenuation occurring at 16~17kHz, shattered on high range rather peaking. It makes attacking sound bold like high-hat at treble. Just think about thicker steel plate.
 
If you prefer clear-high range which is like Final audio labs, FI-BA-SS, Pristine might sound like degradation phenomenon which occurs at low-resolution music. Meanwhile, if you prefer to listen to comfortable treble, Pristine would be great for you.
 
Bass

1. Fast response and tranquil reverberation

 
You can still get the chunks and steady sound compared to IEMs which are usually used for monitoring purpose. Well, it depend on music, but except for little emotional resonance, Pristine makes solid sound. It also reproduce what music exactly has. Although it feels like you can’t hear the low-end because the volume of low-end is not loud enough, bass response on the whole is does not affect other frequency band. At lower frequency, the sound rapidly fade out. You might misunderstand that you can’t hear treble and bass depend on the devices you use. That is the reason why I emphasize on the sources.
 
In-Ear Speakers

1. High-end IEM that has signature sound

Pristine’s name comes from the will to deliver ‘raw’ sound, the music itself. But Pristine sounds different from other IEMs. Some people say they can’t hear treble and bass, meanwhile, some people say soft and warm sound.
 
Pristine has basic that high-end IEM should have included. However, it depend on what kind of IEMs you have used before Pristine and depend on music and devices. It could easily lead you to think Pristine is hard to be paired with other components, but with this much high-end product, it’s really fun to find perfect-match devices. Pristine is worth so much time.
 
Pristine reminded me of Shure SCL5 while listening. Therefore I listened SCL5 with 2 big BA, resistance of cable splitter, capacitors, again. It was not that splendid compared to IEM today, but still attractive.Pristine and SCL5 have only one thing in common, which is dual drivers, but the reason why Pristine remind me of SCL5 is that both are really attractive IEMs. Pristine has its own iconic sound like SCL5, which has been discontinued long time ago but still remembered. If you tired out Pristine, you wouldn’t want to look at any other IEMs which have more than 2 unit!

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Manufacturer website: http://www.hum.hk/pristine/
 
The product was provided to me free of charge for the review purpose in exchange for my honest opinion.
 
* click on images to expand.

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Intro.
 
In my opinion driver number wars are almost over.  Nobody really won, and instead I see more emphasis is being put into sound quality rather than continuing with a race.  As a matter of fact, I’m starting to notice a new trend where some manufacturers are challenging themselves with “less is more” approach to deliver the premium performance with less drivers.  One of these products came out of nowhere from a newcomer HUM, known previously for their android based Pervasion DAP, who generated quite a buzz with their Pristine in-ear monitors after the recent CanJam in SGP.
 
It's a bold move to release your first IEM product with an aim at the TOTL premium market and to set a design challenge by limiting its building blocks down to only 2x BA drivers.  I don’t think their intent was to re-invent the wheel, and instead they approached the design with a “pristine” idea of evaluating every single component in the chain and how it affects/contributes to an overall sound.  They really did their homework and ended up acing the challenge.  Now, let me share with you what I found after spending a month testing and analyzing their Reference in-ear monitor model Pristine-R (P-R).
 
Unboxing and accessories.
 
HUM packaging is another example of common Pelican 1010 micro case with everything stuffed securely inside.  The case arrived with a personalized HUM plate on the cover, and the fact that I received P-R without a single scratch speaks highly for the case durability as it traveled half way around the world.  The negative of minimalistic packaging is the lack of spec or any fancy artwork, though you can always visit their website in hope to find more details.  Surprisingly, HUM seems to reveal just a little bit of info while keeping you in suspense and letting your ears be the final judge of the spec.  There are no secrets about the internal guts or the number of drivers since the universal fit model I received for the review had a fully transparent shell.
 
Obviously, the packaging with Pelican case is also part of the included accessories.  Here, due to the size of the cable with 4 thick braids and a beefy plug, you need some extra room to fit everything in, and 1010 micro case is just perfect for the job, not only to protect shells but also to fit the cable.  Also, included was a set of silicone hybrid eartip pairs (with red core) in S/M/L size, and a basic cleaning tool for nozzle bores.  This is definitely a very basic accessories selection, limited by the room inside of the Pelican case, but I still would suggest for HUM to include more tips for universal P-R model since you can never assume that users will have extras for tip rolling.  Perhaps adding foam tips and maybe a set with double/triple flange tips would be a good idea.
 
Overall, packaging and selection of accessories is very minimalistic, though with an exception of maybe including a few extra sets of different eartips – nothing more is needed.
 
 
 
 
Cable.
 
For some people the beauty of the cable is within its look, personalizing the appearance of IEM/CIEM.  For me, I don’t care as much how it looks as long as it's pliable and comfortable, neatly braided/twisted, and shows some sonic improvement.  This improvement could vary from being very subtle to rather noticeable, and also depends on a pair-up and synergy with a source.  In general, don’t expect a similar level of improvement from using the same cable with different pairs of headphones and sources.
 
While working on the design of P-R, the HUM team took under consideration every single piece of audio equation, including the custom cable (CX1 model) which comes standard with their reference monitors.  They decided to go with a high purity copper Litz wires known for having one of the highest electrical conductivity property.  The original CX1 cable was 0.1mm * 60 strands of pure 99.99% copper, covered by silk shielding.  That made wire quite stiff after tooling which also introduced some microphonics.  The new CX1 cable I received with my review unit is a modified version which has 40 instead of 60 strands sheathed by high quality Dupont TPE material which makes cable softer and more pliable.
 
The headphone plug was right angled heavy duty gold plated 3.5mm TRS connector with a shrink-wrapped strain relief.  It's a good connector but doesn’t have slim enough collar to be more friendly with thick smartphone cases (for example, if you choose to use P-R with your Otterbox case).  All 4 braids are neatly braided and separated going down to the connector where grounds get joined (though, making it easy to re-terminate cable balanced if you choose to later).  Y-splitter is a neat slim metal cylinder; looks much cleaner than a typical shrink-wrapped solution.  Chin-slider is just a clear piece of a plastic tube.
 
Thank God there was no memory wire, and twisted pairs going to individual mmcx connectors are soft enough to stay securely behind you ears for over-ear fit, though believe it or not you can still wear P-R with wire down.  HUM used high quality Amphenol RF mmcx connectors which they recommend as a preferred option when you are customizing their monitors (2pin is also available), but the connector housing is very DIY-ish, just a shrink-wrap.  When you look inside of the connector/housing you can see Red/Blue color to distinguish corresponding Right/Left sides.
 
 
 
 

 
As much as I enjoyed the sonic characteristics of the stock pure copper CX1 cable, which imho is so FAR from being plain "stock", I was still curious to try it with a few of my other premium mmcx cables to see if the sound will scale up.
 
Stock (CX1) vs ALO Litz SPC - ALO adds a little more rumble to sub-bass, lifts it up just a bit while mid-bass is unaffected.  Furthermore, ALO smoothes out upper mids, making vocals a bit more organic and smoother; but it also takes away a bit of the revealing reference quality edge and reduces overall transparency.  Treble becomes a bit smoother too.  I also found the soundstage width improved a little bit.  Even so the cable change improved bass and soundstage expansion, it took away some of the transparency and reference quality.  I actually preferred going back to CX1 cable, though ALO cable looks stunning next to a clear transparent shell of Pristine.
 
Stock (CX1) vs Super BaX – the soundstage remained the same, but I did notice that sub-bass with Super BaX showed a little improvement with deeper impact, while at the same time I hear that mid-bass became a bit slower and more relaxed in comparison.  Upper mids and treble became a little smoother and more organic, but that also took away some transparency of the sound, not as much as with ALO Litz, though.  Performance of Super BaX cable was a compromise between the revealing brighter neutral sound of stock CX1 cable and smoother warmer change introduced by ALO cable.  Definitely an alternative to consider if you find Pristine sound a bit too bright/revealing for your taste, but I still ended up going back to CX1.
 
 
 
Design.
 
In the intro of my review where I talked about the driver number wars, I already mentioned that HUM goal was to come up with a high resolution stage monitor design utilizing only 2x BA drivers with a 2-way crossover.  Actually, it wasn’t much of a challenge but rather their belief in achieving the perfect coherency of a sound by using minimum number of drivers.  Though only 2, those were carefully selected to cover the full bandwidth of frequency spectrum.  Furthermore, HUM handpicked and carefully selected every single component of the design, from using brand name Vishay MELF resistors with a tight tolerance (resulting in more precise crossover point), to using a rather rare for IEM design electrolytic capacitors (with brand labeling stripped?) which intended to be more stable over the time/temperature.  Even the internal wires connecting drivers, crossover components, and premium Amphenol RF brand name mmcx connectors were all 99.99% pure copper Litz wires, the same as a cable.  I believe, they also used premium lead free solder.  No expenses were spared, only the highest quality components were used.
 
The P-R is available in both universal and custom fit where you can customize the shell and the faceplate color, add faceplate artwork, and even choose connector type (though HUM has a preference for mmcx).  In my opinion the best design to showcase the inner beauty of these monitors has to be the transparent acrylic shell which like a glass capsule reveals every component inside.  The shell finish is very smooth, high quality, faceplate attachment is seamless, and I like the integrated look of the mmcx round connector where nothing sticks out or exposed out of the shell.  Inside, you can clearly see 2x BA drivers, and a cylindrical electrolytic cap which is as big as the driver itself.  There are also some discrete crossover components, and multi-strand thick litz copper wires.  Nozzle has just a perfect length and you can see two bores connected to each driver.  Due to a slightly thicker nature of the nozzle, I had no issue trying different eartips where they always stayed tight and secure.
 
The only thing I had a bit of a problem with was a lack of L/R marking.  Since the shell design is not exactly symmetric, you can still figure out which one is left or right, but at a glance sometime it’s not that obvious since neither shells nor cables are marked.  It’s not a show stopper, but I wish HUM would come up with some way to distinguish the sides, perhaps on the cable side.  Regarding the actual fit, though preferred way would be with a wire over your ears (for a more comfortable and secure fit), I found it to work with a wire down too, still providing a good fit and a decent isolation.
 
 
 
 
 
The fit.
 

 
Sound analysis.
 
Due to a nature of premium components internal to the design, especially electrolytic capacitor and solder joints with litz wires, I left P-R on a burn in for 150hrs before starting my sound analysis.
I found P-R to have a reference quality highly resolving transparent non-fatigue sound with a flat neutral tonality that has a light hint of brightness.  In general, I don't hear it emphasizing any particular part of the frequency spectrum, and it reaches its reference quality without a need for bright harshness. The signature and tonality is very effortless, just a coherent flow of the high resolution sound with an accurate natural tonality.
 
Low end is not exaggerated, starting with a deep extension of sub-bass where you can hear a textured rumble without feeling any extra weight or bulk.  Mid-bass is fast, punchy, with a natural decay speed, and overall tight and articulate low end performance, under control and without any spillage into mids. Lower mids are not too thick or too thin, just an average natural tonality that adds to the body of the sound without any artificial coloring.  Upper mids also oozing with a natural tonality, very clear and detailed, never harsh or bright.  I don't hear too much warmth, but vocals are very smooth, organic, and detailed.  Treble is bright, detailed, well defined, and with a realistic and natural level of airiness.
 
Soundstage has a nearly holographic expansion in all 3 directions, with a non-artificial natural spacing.  These monitors have a great imaging and positioning with an excellent placement of instruments and vocals where I can accurate pin-point position of every sound in space. This goes along with an excellent layering and separation with air between the layers - a natural transparency of the sound.
The sound of these IEMs is perfect for those who want a reference quality performance without harsh revealing sound.  Though I consider the tonality to be neutral, the sound is still very exciting and full of energy.  The clarity level is high, you can pick up all the little nuances in sound, and at the same time the sound is smooth and natural.  Everything is in moderation without any over-emphasis, just a non-fatigue detailed sound which is great during extended listening sessions.
 

 
Sound comparison.
 
Pristine vs ES60 - ES staging is a bit narrower and deeper, a little more sub-bass while overall low end is a little slower, not as tight or articulate in comparison to Pristine.  ES lower mids have a little more body which adds more warmth and smoothness to the sound, especially in upper mids were ES sounds more organic, while Pristine is more detailed, more revealing, and more transparent.  Pristine treble is also crispier and has more airiness.  In comparison Pristine sound is more neutral and brighter.
 
Pristine vs Andromeda - Similar staging though Andromeda has a little more depth.  Pristine low end is more neutral in comparison to Andromeda having more sub-bass and a little more mid-bass impact.  Andro lower mids are warmer and have more body, and upper mids are smoother and more organic, not as revealing or detailed as Pristine.  Pristine treble is also brighter, crispier, and with more airiness. One noticeable difference is that Pristine has a better layering/separation with more air between layers which gives sound more transparency, while Andromeda has a more fun tuned sound which is a bit congested in comparison.
 
Pristine vs Sirius - Soundstage depth/height/width are similar. Sirius has deeper, meatier sub-bass, while Pristine has faster mid-bass.  Pristine lower mids are leaner and a little thinner in comparison, while Sirius has more body, and upper mids in Pristine are brighter and a little more revealing; Sirius upper mids sound smoother and warmer in comparison.  Pristine treble is more crisp and brighter, but otherwise have a similar extension and level of airiness.  While Sirius is more balanced with a smoother tonality, Pristine is more reference quality with a more neutral sound and revealing tonality.
 
Pristine vs K10UA - similar height/depth, but Pristine has more width. K10UA has more sub-bass and stronger mid-bass impact, while Pristine is more neutral in comparison. K10UA lower mids are a little thicker in comparison, and upper mids are not as revealing, but equality detailed and with a great clarity.  Treble is very similar, both having a crisp, well defined treble with decent amount of airiness.  In comparison K10UA sound is more balanced while Pristine is more neutral and reference with a better transparency.
 

 
Pair-up.
 
Micro iDSD - dead quiet, neutral detailed sound, good sub-bass extension (not much quantity), punchy fast mid-bass, lean detailed revealing mids, bright crisp airy treble.
 
LPG - noticeable white noise background hissing, flat sub-bass (quality vs quantity), punchy neutral mid-bass, flat detailed revealing mids, bright crisp treble.  Great soundstage expansion.
 
N5 - rather noticeable hissing, wider soundstage, slightly better sub-bass but still with quality over quantity, fast punchy mid-bass, mids a little brighter and not as natural, and a bit pushed back.  Treble is crisp and airy.  Not too crazy about this pair up due to hissing.
 
X5ii - noticeable hissing, average soundstage, neutral flat presentation, sub-bass extension is not as noticeable, mostly mid-bass punch.  Mids are on a thinner side, bright revealing, but lacking some body. Treble is bright and crisp.  Not the best pair up.
 
DX80 - with a stock CX1 cable I hear lots of hissing, while with ALO Litz it was more under control.  The sound was actually more balanced (using ALO cable).  I hear more sub-bass, faster punchier mid-bass,  overall tighter and more articulate bass, clear detailed smooth mids, bright, crisp, airy treble.  Excellent pair up once you switch the cable. Great soundstage. 
 
L3 - above average soundstage expansion, excellent balanced sound; I hear more sub-bass now with a tight punchy mid-bass and overall articulate low end.  Clear detailed mids with natural smooth tonality, bright crisp airy treble.  Excellent pair up.  No hissing.
 
L5Pro - some hissing; excellent balanced sound; sub-bass has more quantity, though not as much as in L3, nice mid-bass punch; though overall low end is not as articulate as L3.  Mids are clear and detailed, a little brighter than L3; treble is bright and crisp with nice airiness (a bit less than L3).  Good pair up.
 
X7 w/AM2 - some hissing; above average soundstage; tight articulate bass with neutral sub-bass and punchy mid-bass (not as fast).  Mids are clear and detailed, but more reference quality, not as organic, and treble is bright crisp and with plenty of airiness.  This pair up did sound flatter.
 
Opus#1 - some hissing; above average soundstage; tight articulate bass with neutral sub-bass and punchy mid-bass.  Mids are lean, bright, detailed, lacking some warmth, a bit harsh; treble is bright and crisp and airy.  I was just OK this pair up.  It’s a bit more on a bright neutral side.
 
For those who crave a flat reference sound, pair up with neutral and brighter tuned DAPs is more suitable, while warmer sig DAPs add more sub-bass and improve mids tonality, making them smoother and more organic.
 
Conclusion.
 
Not every product generating a buzz is actually buzz-worthy, but in my personal opinion HUM Pristine-R definitely deserves a praise.  This is not just another multi-BA driver IEM trying to make its mark in already over-crowded TOTL market.  P-R actually brings something refreshing to the table by thinking outside of the box with their crossover component selection, premium wiring inside and outside of the shell, and scaling up their sound quality by scaling down to a dual driver config.  Every element of this design was well thought of and carefully selected to deliver a reference quality highly resolving non-fatigue sound.  Plus, you get a premium beautiful cable, excellent isolation, a very comfortable fit, and a mesmerizing view inside of the shell with neatly arranged two BA drivers, shockingly big electrolytic cap, and all these pure copper wires.  Can't wait to see and to hear what HUM is going to come up with next and how they are going to top Pristine-R release.