500+ Head-Fier
I received this one a while ago making this review a bit overdue but always had it on my mind.
I will try to keep this review short and to the point.
I have reviewed 10+ T-Peos in the past and to be honest, at first I felt it was going to be like all the other T-Peos in-ears. Not to say that they were bad in anyway, but they had a sound about them that made them sound T-Peos. However, my experience with the 'Rasiel' was surprisingly different.
To clarify some of the things on the box, TGD is the brand they will be released under in Korea as they are domestic partners only here in South Korea. T-Peos is original manufacturer of this product and will be released in to the overseas market as a T-Peos product.
To give a brief background of T-Peos, they are a well-known South Korean in-ear brand first notorious for their line of affordable products that maximize in cost effectiveness and second in their superb quality of high-end multi-driver hybrid flagship series that competes with top-tier brands all over the world.
On multiple occasions, I've had the honor being able to meet several T-Peos staff as well as the CEO in person in Korea and they were such kind people who showed passion. I am excited to see what products they will release in the future.
Here are the specifications:
Connector : 3.5mm 4 pole 24k gold plated L-type plug
Driver : Single dynamic 10mm driver
Sensitivity : 110 +/- 2dB
Power : 3mW / 20mW
Impedance : 8ohm +/- 15%
Frequency Range : 20Hz ~ 15kHz
Weight : 8g
other specs:
- one button remote
- mic
- 1.2m twisted cable
- chrome alloy housing
- alloy reinforcement where the cable splits
Accessories include:
- 3 pairs of silicone tips (s, m , l size)
- Comply t-400 medium size one pair
- cable clip (written on the box but didn't receive with the reviewed product)
- fabric pouch (written on the box but didn't receive with the reviewed product)
There are a couple things appreciated about the design of this particular product apart from the other T-Peos products I had experience with in the past. First, I really like the twisted cable that increases durability and minimizes tangle. The cable is then reinforced by an alloy piece where the cable splits to left and right. Second, despite the housing being 100% metal, it is very light and sturdy in the ears. Also, I want to acknowledge the housing design. It is round and organic in a 'tear drop' shape which is a design seen in other top tier brands.
One thing I would like to recommend is putting the cable over the ears which will cut 99% of the cable noise especially if you're exercising or walking around with these on.
When observing the package, I noticed it said "Powerful Bass" on the side of the box as one of the key features of the Rasiel. And indeed it does have powerful bass! This is the first thing I noticed with the first song I tested. The deep rumble keeps the rhythm alive and enjoyable whether you're listening to hiphop, edm or jazz. The mids are smooth and express every melody in such a fluid way. The treble lets off a good amount of sparkle to increase clarity without causing any unbearable sharp sounds. This all comes together with an impressing soundstage and imaging where you can vision the direction where certain sounds are coming from. The overall sound is quite warm like a "tube vacuum" sound would be.
I would like to finish off by saying that T-Peos has done something here with attempting to give an in-ear "tube sound" qualities and it seems they've pulled it off. Considering it's price point (approx. $40 USD), the Rasiel is an excellent product for today's popular up-beat music trend and the also the occasional retreat to sit-back and relax with acoustic or jazz tunes.

Peter West

New Head-Fier
Pros: Inexpensive, Surprisingly comfortable. No-twist cord. Fun "tube" sound. No need for external amplifiers. "Killing sound".
Cons: Fun "tube" sound, Loads of bass can overwhelm detail. Affects male and female singers differently.
Okay this review keeps getting delayed and I apologize. I often type my reviews as I listen to whatever device is under review. This usually works for me but I have a problem with the TGD (the Korean brand name for what we know as T-Peos) Rasiel "Killing Sound" earphones. I like the sound so much that I get lost in the music and I stop typing. This is not a good thing when you're offering a review.
So much for being objective. I like these inexpensive, pretty, comfortable earphones with their "vacuum tube" sound.
BTW as part of the normal disclosure T-Peos reached out to me and asked if I'd do a review of the Rasiel earphones. There was no incentive offered nor asked for and as previous reviews show I won't hesitate in giving my honest opinion. In a previous life I was a news reporter, community newspaper editor and group editor of a bunch of Canadian national magazines I had a pretty tough reputation for honest reporting and it's a tradition I bring to my reviews of audio equipment.
In my reviews I rarely talk about packaging, accessories or highly technical information which I leave to others. My reviews focus on two things really. Did I enjoy my experience with the unit in question and is it worth the price?
Again for background I tend to compare audio components as a way to determine if I like what I am hearing. I've had other earphones from T-Peos (D-202N and Baguette earphones both of which I liked...a lot). I also have Shure 535s and Dunu Titan 1s and I'll be using all of these in the review. In addition my reference units are Audeze LCD-Xs and a bunch of lesser headphones (Sennheiser Momentum on ear - which are terrific; Sennheiser 590s and modified 439s and Fostex T50RPs all of which won't be considered in this review.
Also I normally drag out a bunch of DACs and amps (Fostex HP-8ac; Aune 1Xs, and a bunch of very serviceable Fiios along with a Picollo amp., Aune B1 and again a bunch of Fiios. Reviews around here can take nearly a hundred hours of listening if I get something that is really challenging.
But there's no challenge here when it comes to the Rasiel earphones. If you're looking for something that's fun to listen to and is as comfortable as old socks then the Rasiel's are for you.
There are some serious audio issues but we'll come to that soon enough.
Here's what's great about the Rasiels. These are one of the very few in-ear earphones that I can leave in for hours and hours at a time and this with the standard rubber tip. Some of the other in-ears needed changes to their tips to be comfortable and even then after an hour or so my ears were happy to have a break. Not the Rasiels. In my ears they rest perfectly. There's something to be said about earphones that are actually comfortable right out of the box. (It took me weeks to get used to the Sennheiser on-ear headphones. Painful break-in but worth the effort.)
But not all is perfect in Rasiel heaven. When the earbuds are pushed into the audio canal they create a seal and a near-perfect seal causes the huge boost in the bass. It's a lot like hitting the bass boos on my Fiio E10K. It's boom, boom, boom in my head. When listening to Bob Marley and Whalers this isn't such a bad thing but  listening to Shelby Lynne's 10 Rocks which starts with a piano rumbling away in the bass register the Rasiels sound pretty muddy and unbalanced when compared to the Titan 1s. Shelby wouldn't be happy.
You'd almost think you were listening to different cuts of the same song as each earphone has its own signature sound but the Raisels take this a step beyond.
On the Titan's Shelby's voice is blended with the bass line and the backup singers are as sharp as diamonds.
On the Rasiels it's a very different mix. Shelby Lynne has a barroom lower-register voice and the Rasiels give it their advertised "tube sound and in this case that's not a good thing.
For fun I listened with the Shure 535s and the bass rumbles along as Shelby's voice rises above. The backup singers aren't as sharp. It's a different sound and one likely more accurate to what the audio engineer created.
Let's go back to Rasiels: The base is way more rumbly and not as tight but Shelby is still just above the fray and the backup singers are sharp. They're not as sharp as on the Titans but sharper than the Shures.
Next up (I've using my Astell and Kern AK-100 II as my source with random songs being auto selected) Don't Stop by Fleetwood Mac in the Ttian's sound anemic when compared to the weighted sound of the Rasiels. Which brings us to our next topic...the tube sound.
We're got a Korean guy in our Toastmaster club (I've been a member for over 20 years. Highly recommended.) and he's very new to Canada. I wouldn't call English is second language yet but he's trying very hard and his efforts to speak the Queen's English is one of the bravest thing I've ever witnessed but sometimes he just murders the meaning of the words.
So when it comes to T-Peo's marketing department I think we have to read between the lines sometimes. Their tagline about the Rasiel "killing sound" might have better been written as "killer sound" but we get the point don't we?
Same for the next line "Filled with the Sound of Vacuum tube". I know what they mean and where T-Peos is coming from is the bass and treble boost that colours the sound and can change the way the mix was meant to sound. For example, Dwight Yoakum's voice in his song Wild Ride through the Rasiels is push back so far as to sound like there's a faint echo. In the Baguettes Dwight's voice is much more prominent. It's still got an echo but it's not being overwhelmed by the bass. 
I was so confused by what I was hearing I got out the Momentums which immediately calmed down the sound.
If you read the other reviews on the Rasiels (and I always do as some of these guys know more than I'll ever learn about audio) and you'll see that the audio signature of the Rasiels is described as being a "W". That's to say the bass is boosted. There's a boost in the lower mid-range frequencies and a lesser boost in the treble top end.
So what you get with Rasiels is a simulated "tube sound" which emphasizes the bass and lower mid range, then scoops out the middle and adds a kick to the top end.
This audio signature works for a lot of music. Bob Marly and Whalers sound great. You can follow the bassline like a road map. It's that prominent. Tom Waits's gravelly voice never sounded better. Because Simon and Garfinkel sing in higher registers the Rasiels like them too. Just about any acoustic guitar sounds amazing. Jesse Cook just sizzles in the Rasiels. Jazz as played by Miles Davis is very cool. Kinda tube like if you know what I mean :)
Joni Mitchell makes the cut as her voice is pitched in the higher registers that the Rasiels emphasiz while on the other hand Heart's Ann Wilson's voice is a little lost in the group's mega hit Alone. 
You can (and should) do your own testing and remember your mileage may vary.
It depends. What the Rasiels have is character. I like characters in my life and I like earphones and headphones with character. Sometimes the character can overwhelm the experience and that's not a good thing but character on its own isn't necessarily something to run away from.
For most of type of music I listen to the Rasiels reproduce the sounds beautifully even dramatically if you will. And if you don't go around comparing every phrases from one earphone to another you're not likely to notice the Rasiels when they miss reproducing the sound in the way the audio engineer set it up.
One reviewer said he knew the sound was "wrong" but it was "super fun" and I agree totally.
Some earphones and headphones which approach studio quality or the even higher demands of the audiophile aren't that interesting to listen to for hours. Sure they're accurate as an arrow but after an hour or two I find myself longing for a little colour in my music. And try wearing the LCD-Xs for hours at a time. They weigh a ton and while the pads are comfortable it's a lot of weight and eventually I have to take them off. (I know: Poor me!)
I also like how extremely comfortable the Rasiels are for in-ear earphones. This is a big plus.
Same too for their non-twist cord. I've got earphones that have cords that immediately tie themselves into knots every time you put them down. Not fun.
Also the cord is non-microphonic. In other words it doesn'tt transmit rubbing sounds when worn. I've got a set of old Sennheisers that you can't take for a walk as the cords make so much noise when they rub against clothing as to make listening an unpleasant experience.
Most reviewers think the chromium plated brass looks good and I agree.
Oh did I mention price? While there is no published price yet that I know of the other reviewers are saying they're going to retail for $40 US (likely $60 Cdn). $40 is the cost of a decent lunch these days so this is a no-brainer. Fun, comfortable, pretty with a few accessories (small selection of rubber and foam tips) what's not to like? Well the weighted sound may not be for everyone but I like it.
Finally, and this was a surprise, the Rasiels don't need an external amplifier to sound good. In fact I found external amps tended to overdrive the sound when using the Rasiels. The AK-100 II into the Class-A Aune 1 amp and using the Titan's is superb and the same can be said using Momentums. The Rasiels however still repress the frequencies where Ann Wilson lives and the amp only emphasizes this effect. The Momentums and Titans bring Ann's voice back in front.
Remember if you're not comparing every song most times you're not going to notice a little shifting of frequency response. What's really nice is switching out the external amp and hearing no real advantage. My LCD-Xs really respond to the Aune B1 amp and sound way better thanks to its colouring and overall boost. But the Rasiels don't resond in the same manner. That's not to say some amplification isn't welcome. My Cypher Labs Picallo amp added a little more fullness to the overall sound regardless of which headphone I was using including the Rasiels but if you weren't comparing you'd not know how little you were missing.
The Rasiel earphones work great with DAPs, smart phones and the like and they don't need an external amp to sound great. They're comfortable, pretty and cheap (I'm tempted to make a smart remark here but the Internet being what it is I'll pass.) so what's not to like? Audiophiles may not like them but for the rest of us with $40 or so they make a great purchase and you too will get that real "killing sound" of "Vacuum tube" .
Beautiful :)


Headphoneus Supremus
Pros: Good build quality. Budget-friendly price.
Cons: Needs EQ. Ponderous bass. Non-ergonomic earpieces.


My first exposure to T-PEOS was back when the Altone 200 IEM was released. I pre-ordered it based on @H20Fidelity's impressions. It was my first hybrid IEM, and I really liked it for its killer combination of punchy bass, clarity, ergonomics, and price. Although I don't listen to them much anymore, Altone 200 are one IEM I'll keep in my collection if nothing more than for sentimental reasons. When T-PEOS released the follow-up to the Altone 200, the Altone 150, 250 and 350 lineup, I was able to extensively audition the lineup and provided impressions. The newer Altone lineup saw a break from the punchy, clear sound of the Altone 200. Instead, we got a more consumer-oriented sound with copious bass. With a bit of EQ to tone down the bass the Altone 250 sounded pretty damn good, but for me EQ was a necessity. Even with EQ, I wasn't a big fan of the Altone 150 and 350. Beyond the overly rambunctious sound, the new Altone lineup wasn't very ergonomic with overly large connectors and super springy cables. For my tastes, T-PEOS was clearly headed down the wrong path, and I tried to make that clear in my Altone 250 review and impressions of the entire lineup. With my love for the Altone 200, I wanted to see T-PEOS succeed in recreating the magic. 
That's all fine and good Nikolaus, but we aren't talking about the Altone lineup here, are we? No, we're not. I just wanted to make my history with T-PEOS clear. And when I (as with a few others in the Head-Fi community) was recently approached by James Park to evaluate their new Rasiel IEM, I wanted to see where T-PEOS was at right here, right now. Would Rasiel really be "vacuum tube sound" as the ad copy suggested? Would it be balanced and smooth, or would it fall into the the trap of consumer-friendly bass-heavy sound? The Pros and Cons provide a high-level answer. Read on if you're interested in diving a bit further down into the details...
Rasiel Website: LINK.


T-PEOS sent me a pair of T-PEOS Rasiel in exchange for my unbiased review. I hope my feedback is useful for my fellow Head-Fi members as well as for T-PEOS. 

I'm a 44 year old father who listens to a lot of electronic and metal, although I do listen to a wide variety of music. I'm primarily a portable audio enthusiast and have been in the game since the venerable Shure E2C was first released. Bought one, plugged it into one of my many MD players, and have been hooked ever since. I do enjoy listening at home and am becoming increasingly interested in building up a nice desktop setup. As with a lot of people my age, my hearing isn't perfect but I've be listening for a long time and feel confident in assessing audio gear.



  1. Driver : Dynamic driver 10mm​

  2. Sensitivity : 110 ±2dB​

  3. Power : 3mW / 20mW​

  4. Impedance : 8Ω ± 15%​

  5. Frequency Range : 20Hz ~ 15kHz​

  6. Weight: 8g​





As usual, I'm not going to spend much time on describing the packaging and accessories. It's about what you'd expect at this price point. 
Inside the box, you get the IEM plus S, M, L silicon tips and a pair of M Comply tips. 
Despite the accessories list claims to the contrary, there was no fabric pouch or shirt clip in the box. Odd...



In the photo collage above, you can see Raisel's teardrop-shaped metal earpieces, mic / remote unit, y-splitter, 3.5mm L-plug, and bits and pieces of the cable.
Some thoughts on the design and build quality:
  1. The metal earpieces are quite solid but aren't the most ergonomic. I struggle to acheive a secure fit with silicon tips. Using Comply solves this. This holds true when wearing down or up.
  2. The vent holes are directly adjacent to the strain reliefs. Isolation is okay but not great. If worn down, wind noise isn't an issue. Worn up, the vent holes are quite exposed and Rasiel are more susceptible to wind noise.
  3. The mic / remote module is a simple and functional one button unit. I rarely listen out of my phone, so this isn't something I'd use anyway.
  4. The y-splitter separates the upper non-braided cables from the braided cable below. Unfortunately, there's no cinch.
  5. The 3.5mm jack is a smartphone-friendly L-Plug.
  6. The cable feels solid and isn't prone to microphonic or tangling.
  7. All branding is TGD and not T-PEOS.
Here's how they'll look, assuming your ears are similar to mine...


The basic sound signature of Rasiel is v-shaped, with strong, ponderous bass and elevated upper mids / lower treble. Beyond the sheer abundance, bass speed is ponderous and bass texture is flat. Lower mids suffer from bass bleed. The slow, elevated bass and lower mids lead to a wooly sound. The midrange proper is sucked out. Vocals aren't going to pop here. Upper mids / lower treble are emphasized, so you'll still be able to hear those high notes and cymbals over the copious bass. Not exactly what I go for in an IEM. Definitely more of a consumer-friendly sound.
So what to do? EQ...
Shelf down the bass, drop the lower mids a bit, and bring up the mids proper a bit. That sounds better, but now the upper mids / lower treble are a bit out of balance. Drop those down a touch, and we've got a relatively balanced sound signature. While its definitely better, I'm not blown away. The bass is still slower than I'd like and lacks texture. Oh well, at least the mids aren't sucked out anymore.
I'm not going to go into a deep dive comparing with other IEM I have in this price range. Suffice it to say that I recently received a few other budget-friendly IEM from Alpha & Delta, Rhapsodio, and Vsonic and find myself reaching for the others over Rasiel.


I went into this review process hoping that T-PEOS would surprise me with a more balanced budget-friendly IEM. Unfortunately that wasn't the case. Instead, I found a well-built IEM that didn't fit me well sonically or ergonomically. Looking over other reviews, I'd say I wasn't alone in my thoughts on the overall sound but do seem to be an edge case when it comes to fit since others were able to achieve a good fit with less work than I did. I'd love to be able to recommend Rasiel for a sports IEM because the sound signature seems made for that, however the heavy metal shells and so-so isolation make that a hard recommendation for me to make. In the end, I'd recommend these for those looking for a consumer-friendly sound, durability, and a bit of flash. Unfortunately, that leaves out a lot of the Head-Fi crowd. Oh well, here's hoping T-PEOS takes the critical commentary and suggestions seriously and gives us more IEM like the instant classic Altone 200. C'mon T-PEOS, we know you can do it! 
Thanks again to T-PEOS for providing me with a review sample.
Pros: Build quality, cable quality, price, SQ (if you EQ), upper mid-range
Cons: Bass (overwhelming and bleeds through mid-range), confusing advertising / marketing claims, driver flex
For larger views of any of the photos (1200 x 800) - please click on the individual images
My first experience with T-Peos was a couple of years ago, when I had the chance to review their (at the time) new budget based triple hybrid IEM – the Altone 200. The Altone 200 set a new benchmark for me in sonic signature – especially at the introductory price (at the time) of USD 125.00 – an incredible value. In fact I was so impressed that I actually purchased the Altone from T-Peos and they remain one of my favourites even to this day (every so often I still get them out and am again wowed by their signature). Since then I've had the chance to try their Altone 350 and unfortunately came away less than impressed (too much bass for a flagship), but their build and overall quality was really good. Recently I was approached by James Park and asked if I would like to listen to and review their new Rasiel IEM. With memories of the Altone 200 and after reading a little about them (“filled with the sound of the vacuum tube”), I was pretty excited to try them out.
For anyone who hasn’t heard of T-Peos, the parent company SWP Shinwoo is a Korean electronics company founded in 1986 who started developing earphones in 2012, changed their company name to T-Peos in 2013, and at the same time launched their first 3 way hybrid IEMs. Their focus is on quality (reading their website is impressive), and it definitely showed in the machining of the Altone 200 and Altone 350.
The Rasiel sample I have has some markings under their Korean partner banner (TGD) – and you can find the website here. RRP for the Rasiel is around USD $40
The Rasiel IEMs that I’m reviewing today was provided to me gratis as a review sample. I have made it clear to T-Peos that I still regard any product they send me as their sole property and available for return any time at their request. But I thank them for the ability to continue use of the Rasiel for follow up comparisons. I do not make any financial gain from this review – it is has been written simply as my way of providing feedback both to the Head-Fi community and also T-Peos themselves.
I'm a 49 year old music lover. I don't say audiophile – I just love my music. Over the last couple of years, I have slowly changed from cheaper listening set-ups to my current set-up. I vary my listening from portables (including the FiiO X5ii, X3ii, X7, LP5 Pro and L3, and iPhone 5S) to my desk-top's set-up (PC > USB > iFi iDSD). I also use a portable set-up at work – usually either X3ii/X7/L3 > HP, or PC > E17K > HP. My main full sized headphones at the time of writing are the Beyerdynamic T1, Sennheiser HD600 & HD630VB, and AKG K553. Most of my portable listening is done with IEMs, and lately it has mainly been with the Jays q-Jays, Alclair Curve2 and Adel U6. A full list of the gear I have owned (past and present is listed in my Head-Fi profile).
I have very eclectic music tastes listening to a variety from classical/opera and jazz, to grunge and general rock. I listen to a lot of blues, jazz, folk music, classic rock, indie and alternative rock. I am particularly fond of female vocals. I generally tend toward cans that are relatively neutral/balanced, but I do have a fondness for clarity, and suspect I might have slight ‘treble-head’ preferences. I am not treble sensitive (at all), and in the past have really enjoyed headphones like the K701, SR325i, and of course the T1 and DT880. I have a specific sensitivity to the 2-3 kHz frequency area (most humans do) but my sensitivity is particularly strong, and I tend to like a relatively flat mid-range with slight elevation in the upper-mids around this area.
I have extensively tested myself (ABX) and I find aac256 or higher to be completely transparent. I do use exclusively red-book 16/44.1 if space is not an issue. All of my music is legally purchased (mostly CD – the rest FLAC purchased on-line). I tend to be sceptical about audiophile ‘claims’, don’t generally believe in burn-in, have never heard a difference with different cables, and would rather test myself blind on perceived differences. I am not a ‘golden eared listener’. I suffer from mild tinnitus, and at 49, my hearing is less than perfect (it only extends to around 14 kHz nowadays).
For the purposes of this review - I mainly used the Rasiel straight from the headphone-out socket of my FiiO X3ii + E17K or iPhone 5S, and also a variety of the other DAPs I have around me (concentrating a lot on the portability factor so this included X1 and M3). Although I tested the Rasiel with an amplifier, I do not think they benefit from additional amplification (I use mine mainly for consistency when reviewing and also to extend battery life on the X3ii). In the time I have spent with the Rasiel, I have noticed no changes in the overall sonic presentation.
This is a purely subjective review - my gear, my ears, and my experience. Please take it all with a grain of salt - especially if it does not match your own experience.


The T-Peos Rasiel arrived in a striking retail box, in two tone black and yellow with gold text. The box has a window to give you a first glimpse of the Rasiel, along with a by-line (“killing sound”) which would prove to be somewhat prophetic – and a another phrase which really whetted my appetite (“filled with the sound of the vacuum tube”). On the rear of the box is a graphic of a tube, and below that specs and a list of accessories. The box measures 78 x 145 x 54 mm. Inside is a second 3 sided box/tray with a clear plastic mould to hold the Rasiel. Under this is a hidden compartment which houses the accessories.
Front of the retail box
Rear of the retail box
Side with messages - note the "powerful bass"
The accessories are listed as:
  1. 3 pairs of standard silicone tips
  2. 1 fabric pouch
  3. 1 shirt clip
What I received was slightly different – 3 pairs of tips, 1 pair of Comply T200s (M), and no pouch or clip.
Interior packaging
Included accessories (differ from the box description)
Included tips
For USD 40.00 I can't really fault them so far. There aren't a lot of accessories – but if the build and sound are good at this price point, the accessories will soon be forgotten
(From T-Peos)
Single dynamic driver IEM
10mm dynamic
8 ohms +/- 15%
110 dB +/- 2 dB
Frequency Response
20 Hz – 15 kHz
Fixed 1.2m dual twisted pair braid
Right angled 4 pole gold plated
On cable control
Single push button + mic
IEM shell
Chrome plated alloy
The graph below is generated using the Vibro Veritas coupler and ARTA software. I must stress that they aren’t calibrated to IEC measurement standards, but the raw data I’m getting has been very consistent, and is actually not too far away from the raw data measured by other systems except for above 4-5 kHz where it shows significantly lower than measurements performed on a properly calibrated rig. So when reading the graph, don’t take it as gospel – or at least remember that the area above 4-5 kHz will likely be significantly higher. It is my aim to get this system calibrated at some stage in the future.
The graphs are provided merely as a point of discussion and further in the review you can see comparative data to some other IEMs in a similar price bracket.
Default response and channel matching
CSD - note the bleed through the mid-range
Rasiel vs Altone 200
The channels have very good matching from 20 Hz right through to about 4 kHz, and then from 4-10 kHz they get out of whack a little. I measured several times and the results were consistent. The disparity in the measurements is not really noticeable with music playing, but is with a sine sweep.
The graph pretty much reflects the default sound of the Rasiel – very V shaped with a lot of sub bass, strong upper mid-range, and quite sucked out or recessed vocal area (comparatively).
I've also included a graph of the Rasiel vs the Altone 200 because it really does emphasise the extent of the bass. And the third graph shows the CSD plot. Make note of the extent of the bass decay into the 1-2 kHz area (the heart of the mid-range), as this is something we'll go into more depth on in the sound section.
The Rasiel is beautifully built, and has a horn speaker shape very similar to the Final Audio Design Piano Forte family of IEMs. It is a 2 piece shell – with the front shaped like a cup or dome, and the rear like a cone. There is a visible seam, but it is so smooth I don't really notice it. The shell is a polished chrome plated alloy, and measures 33mm from the tip of the nozzle to the rear of the IEM, and has a diameter of 13mm at its widest point. The nozzle is relatively short (just 4mm in length from the base of the Rasiel shell), but has a generous lip, and tips so far have fit really well. The nozzle is 6mm in diameter at the tip, and has a mesh protective covering. The cable exits the shell adjacent to the central seam and next to it on both ear pieces is a single vent or port. The right earpiece has a single R to designate L/R – whilst the right simply has their house brand designation “TGD”. The IEM shell screams quality for a $40 offering, and my only niggle was that the highly polished shell exterior as pretty hard to photograph (#firstworldproblems) due to the mirror finish and lighting. Seriously though – this is a really nice looking IEM.
Gorgeous finish and horn speaker shape
Nozzle front on
Cable exit and vent
The cable exits are both reasonably well stoppered – which doubles as a short strain relief. The cable is 1.2m, fixed, and consists of 2 s twisted pairs from jack to Y split, and then separated pairs above that. The right hand ear piece has a control unit (single push button) and microphone approximately 20cm from the IEM body. Worn over ear, this sits just below my jaw line. Cable down it sits below my collar.
The push button control is a universal standard (one-click pause/play, two click next track, three click previous track, and press and hold activates Siri on the iPhone 5S for me). The controls work with both the iPhone and also the FiiO M3. The microphone is pretty clear, and I had no problems being clearly understood when test calling my wife.
Quality jack and cable
Mic and push button control
Quality Y-split
The Y split is a metal tube with good strain relief at entry and exit. The jack is right angled, 4 pole (for the remote button), gold plated, and a mix of chrome alloy and rubber. It is also iPhone + case friendly. The overall quality of cable is very good and reminds me a lot of the Trinity cable quality. It also has very low micro-phonics (virtually none when worn over ear). One thing missing though is a cable cinch.
I have one ear canal slightly different to the other one (my right is very slightly smaller) - so I tend to find that usually single silicon flanges don't fit overly well. However the included silicones really surprised me as they fit extraordinarily well, and I have to admit that this shape allows me to comfortably fit a variety of tips that normally I can have issues with. The tips I tried and was successful with included standard foam or Comply foam, Spin-fits, Ostry tuning tips, Spiral Dots and Sony Isolation tips (although the Sonys caused vacuum issues – not enough venting). There was also a bit of driver flex in both ears – which disappeared once adjusted, but is worth noting.
Foam tips - helped control vacuum issues and driver flex
Spiral-dots and Ostry tuning tips
Sony Isolation and Spin-fits
Comfort is excellent – the Rasiel really does disappear into my ears when worn, doesn't protrude past my outer ear, and I could lie down with them quite comfortably. Isolation is really quite good for a dynamic driver, and I would definitely say above average. These would be good enough for public transport.
So the Rasiel has a stellar build, good cable, very good fit, good isolation – are we on the way to a winner? Unfortunately for me this is where the plaudits stopped.
The following is what I hear from the Rasiel. YMMV – and probably will – as my tastes are likely different to yours (read the preamble I gave earlier for a baseline). Most of the testing at this point (unless otherwise stated) was done with my FiiO X3ii + E17K as source, and the included silicone tips or a pair of Trinity foam tips (I swapped over a couple of days listening).
Tracks used were across a variety of genres – and can be viewed in this list http://www.head-fi.org/a/brookos-test-tracks.
Confusion and Mixed Messages
I'm going to start here because the advertising around the Rasiel is a little misleading, although I think I understand what they were trying to convey now (it is still a paradox though). On one hand, T-Peos advertise the Rasiel as “being filled with the sound of the vacuum tube”. I have a couple of tube amps, and I love the second order harmonics they bring. But anyone who's dealt with different tube amps and different tube combinations will know that you can have a range from warm and syrupy to clean and linear (I prefer the latter). The one constant I've found with tube based amps though (apart from the high voltage output) is that the ones I've tried sound incredibly pleasing, rich, and at the same time clean. It is difficult to describe. The Rasiel sounds nothing like this – it is not close. In fact the last thing I would think of when describing the Rasiel's signature would be “tube like”, and if I had a tube amp with the Rasiel's default characteristics, I'd be rolling tubes or getting rid of it.
The second message is “killing sound”, and I do think this is intentional – it isn't supposed to be “killer sound” which is very much a Western term. If you go the Rasiel website you get a picture of a breaking tube with the “killing sound” by-line, and a sentence underneath saying that “the new sound will be heard did not listen to the original”. And here's the paradox – they say it is tube-like, and now they say its not. It's very confusing – and for my money anyway – this does not reflect the way a good tube amp sounds. Which makes their “killing sound” statement quite accurate (or in other words – “breaking the mould”).
Thoughts on General Signature
I was hoping T-Peos would break away from their bass enhanced house sound, but sadly this wasn't to be. From first listen (before I graphed them) I knew within 2 minutes that this was a continuation of a certain house tuning. Very V shaped, massive bass, and quite a nice upper mid-range which sounds quite clear and clean and is pretty good with female vocals (similar to Altone200). The problem is that the lower mid-range is recessed a lot compared to upper mid-range and bass, and this gives perfect grounds for the bass to bleed and engulf lower mids (and it does).
Overall Detail / Clarity
Tracks used: Gaucho, Sultans of Swing
  1. The sax is really good, slightly thin and reedy though, but the first noticeable thing is the bass guitar which just dominates everything.
  2. Detail retrieval is actually pretty good – cymbals are clear and clean with good decay, but some of this is lost depending on drum beat or bass guitar at that particular part of the track.
  3. Guitar has good edge but is thin and a bit peaky on Sultans.
  4. Marks vocals very recessed and thin on Sultans
  5. Overall quite capable of exposing detail, but bass simply overpowers a lot of it.
Sound-stage, Imaging, and Sibilance Test
Tracks used: Tundra, Dante’s Prayer, Let it Rain
  1. Average directional cues, and just on the periphery of my head space – so relatively good width, but little of depth
  2. Imaging is a bit diffuse – but it is the bass with “Tundra”. One of the first times I've heard it so boomy. I won't finish the track – it is too fatiguing.
  3. Good contrast between vocals, piano and cello with Dante's Prayer. Loreena's vocals are quite good (not as rich as I'd like, but they have good presence and air). This track is pretty bass light so it is quite a pleasant experience.
  4. No real immersion (applause section of Dante's Prayer) and instead of the crowd being around me, it is quite flat – good width, but no depth.
  5. “Let It Rain” is a better, a little more holographic, but Amanda's vocals are a bit diffuse and also a little distant. Sibilance is present in “Let It Rain” - I know it exists in the recording. However it isn't overly emphasised, and for me is tolerable. Cymbal presence in this track is good but the bass guitar is starting to dominate again and between that and the distance in the vocals, it almost sounds a little veiled. Not my favourite rendition of this track.
Bass Quality and Quantity
Tracks used: Bleeding Muddy Water, Royals
  1. Uggh – no, and no, and no. Strong sub-bass impact (mid-bass as well), but Mark's vocals are distant and the mid-range is practically lost in the extended bass decay.
  2. Poor speed and bass resolution – strong impact, and very boomy.
  3. A lot of bass bleed into the mid-range
  4. Massive sub-bass and rumble (“Royals”) and for me it is hugely excessive, and bleeds all over Ella's vocals – drowning them out in passages.
  5. Good bass does not sound like this.
Female Vocals
Tracks used : Aventine, Strong, For You, Human, The Bad In Each Other, Howl, Safer, Light as a Feather, Don’t Wake Me Up, Ship To Wreck.
  1. Good transition from lower-mids to upper-mids lending nice euphony and sweetness to female vocals
  2. “Aventine” is a little hollow and the cello is slightly out of contrast (too strong) compared to Agnes vocals
  3. “Strong” is good but the deep bass dances on the verge of drowning some of Hannah's vocals, and they sound a little thin (and on a well tuned IEM they really aren't)
  4. Big bass impact with music with highly dynamic content (Feist, FaTM). Some will probably like this – I just find it too overemphasised and fatiguing after a while.
  5. Tracks with lower bass impact are actually pretty good (Gabriella Cilmi was really rather nice), and I can't wait to EQ these to get some balance.
  6. Mixed bag with female vocals. There is a mid-range in there, but it will need to be coaxed out.
Male Vocals
Tracks used: Away From the Sun, Art for Art’s Sake, Broken Wings, Hotel California, Immortality (Seether unplugged), Keith Don’t Go, Elderly Woman Behind the Counter in a Small Town.
  1. Male vocals are a lot thinner, and very distant comparative to bass.
  2. Surprisingly good portrayal of older classic rock artists like 10CC. Good detail with nice presentation of vocals – but I'd still like to dial that bass back a bit.
  3. Eagle's “Hotel California” was great until the drums kicked in (finger picked guitar was brilliant) but again the bass line is boomy and simply over done.
  4. Nils Lofgren's “Keith Don't Go” showed again that there is actually a really good mid-range with the Rasiel – it's just not allowed to breathe. Vocals on this acoustic track were in a lot more balance. Quite enjoyable.
  5. Pearl Jam was not good – too much distance on Vedder's voice and once again the bass guitar dominated, and even started drowning out some of the slow cymbal decay which makes this track one of my favourites.
Genre Specific Notes
I started to go through my usual repertoire but I had very little positive to say with virtually any of the genres I usually test with. Bassy tracks (EDM, Trance) are overdone, vocal tracks are too distant and often muffled. Alt rock tracks which often have a lot of detail (Floyd / PT) were often muffled. Even Classical sounded unnatural. By now my ears were thoroughly fatigued and it was time to call it quits, and look at amplification, EQ and comparisons later in the week.
The Rasiel is easily powered straight out of the portable devices I have, and I haven’t experienced any issues with the iPhone 5S, or any of the FiiO DAPs. With typical pop/rock songs on the X3ii and E17K, 20/60 on low gain (E17K) gets me 65-70dB and that is more than enough for me. With the iP5S I’m usually at a volume level of around 25-30%. Amping netted no rewards, and ironically, introducing tubes (the IMS HVA) only made things worse.
Time for redemption. My main issues with the Rasiel are the overwhelming bass and the distant lower mids. To fix the first I lowered the bass using the E17K by 8dB (much better), although the upper mid-range was now a little too accentuated and peaky. Simple to fix and simply involved an equal drop of 8dB treble, and lets try again with Pearl Jam. Ahh – much better. This is a signature that allows the music to breathe, and the Rasiel responds well. I’ve graphed the difference so you can see the effect. I would pay for this signature as a default.
Reluctantly I dropped the EQ back to flat again and prepared to compare it to some IEMs in a similar value category which are also quite bassy and V shaped. I the end I chose the Rockjaw Arcana 2, Trinity Hyperion and Brainwavz S0. All of these comparisons are very subjective – and influenced by my own preference, physiology and bias. Comparison was once again with the X3ii + E17K
T-Peos Rasiel ($40) vs Brainwavz S0 ($30)
Rasiel vs Brainwavz S0
Comparative frequencies
Looking at the total package, both have extremely good overall build quality and are extremely comfortable to wear. The Rasiel has a far better cable (I'm not a fan of the Brainwavz S0 flat cable), but the S0 is miles ahead in terms of accessories. Sonically the S0 is very warm with a huge mid-bass hump and quite veiled mid-range due to the combination of mid-bass and quite subdued upper mids and treble. The Rasiel is much more bassy, but it is counter-balanced by the quite bright treble. In a direct A/B comparison, my preference lies with the Rasiel – simply because it is clearer overall. The bass is a lot stronger though – really surprised me. Neither are good examples of a balanced signature.
T-Peos Rasiel ($40) vs Trinity Hyperion [discontinued] ($40)
Rasiel vs ​
Trinity Hyperion
Comparative frequencies​
Both again have extremely good overall build quality and are extremely comfortable to wear. The Hyperion has the slight edge in fit as they do literally disappear due to their size. The accessory package is definitely in favour of the Hyperion with a good carry case and bigger choice of tips, and this time the cable quality is evenly matched, and maybe slightly in favour of the Hyperion. Sonically, the Hyperion has more mid-bass than sub-bass where the Rasiel is the opposite. Both are V shaped, and both have a nice mid-range with emphasis on upper mid-range and a relatively recessed lower mid-range. Where the Hyperion excels though is in a far better balance, and nothing is masked or veiled. This comparison isn't close – they Hyperion is the far better performing earphone.
T-Peos Rasiel ($40) vs Rockjaw Arcana 2 ($40)
Rasiel vs RockJaw Arcana2
Comparative frequencies​
Its likely that not too many people have heard the Arcana2 – and it is one of the few very bassy earphones which really ticked my boxes at the time. Like the Rasiel it has a very V shaped frequency plot with strong sub-bass, but I'm getting ahead of myself. Both have good build quality and similar accessory packs (assuming the Rasiel eventually does come with a cloth carry bag and shirt-clip). But the quality of build materials and finish on the Rasiel is better, as is the cable. The frequency plot is very similar with the major difference being the relative amount of sub-bass and upper mid-range compared to the lower mid-range. And even though the plots are similar – in relative terms (for a V shaped signature), the Arcana is simply more balanced – and this means less bleed. It's still very warm, and now when I hear it I am probably less enamoured to its overall signature than I one was. If I could transfer the Arcana's sound signature into the Rasiel's body, you'd have a pretty good “bass oriented” earphone.


It's funny how disappointed you can be when you're hoping for a signature similar to one you once had from a company. I loved the original Altone 200 from T-Peos. It scored 4.5 stars from me when I first reviewed it, and I still get it out every now and again when the mood takes me, and I am still wowed by its tonality. At the time it redefined how good a triple hybrid could be for sub $150. And the Rasiel has a lot of good things going for it. It has a stellar build with a good cable, and fits very well indeed (great comfort level for me). It's also priced at a level which is very affordable, and for this sort of build quality that is not a common thing.
But by trying to break the mould, and aim for something which is very much bass enhanced, they've simply gone to far IMO. There simply is no possible excuse to have an earphone which bleeds so badly into the mid-range, and there ultimately lies its main issue. It simply has no balance – just a strong V shape which is out of proportion to the mid-range. And this is ultimately very fatiguing. Now I'd be the first to admit that I'm not the intended audience for this earphone (middle aged white bloke who prefers a brighter – or at least more balanced – signature), but I can't go past the fact that most bass-heads I know are also fans of quality bass. And this isn't quality bass. It's just quantity bass. "Bassheads" are often misunderstood, and my discussions with @Hawaiibadboy over the last couple of years have given me a better appreciation of the sort of bass quality he looks for. I don't think he'd like the Rasiel either. 
I hate giving 2.5 stars with the Head-Fi rating system, because it scores as a negative rather than neutral, but I simply can't give this earphone a 60% (3 star) ranking. Sadly – I would not recommend the Rasiel to anyone I know. There are far better IEMs out there. Once again though, I’d like to pass my thanks to James and T-Peos for giving me the chance to try these, and I am genuinely sorry that I can't give them more positive comments.
Start again from the Altone 200 signature (I've told you this before) – and build a better more balanced IEM from it as a base. I really look forward to seeing what you can do with a different direction. Sadly this current pursuit of bass at any cost is not helping your reputation (with me at least).
Good review:
"For anyone who hasn’t heard of T-Peos, the parent company SWP Shinwoo is a Korean electronics company founded in 1986 who started developing earphones in 2012, changed their company name to T-Peos in 2013, and at the same time launched their first 3 way hybrid IEMs. Their focus is on quality (reading their website is impressive), and it definitely showed in the machining of the Altone 200 and Altone 350.
The Rasiel smaple I have has some markings under their Korean partner banner (TGD) – and you can find the website here. RRP for the Rasiel is around USD $40"
I bolded the a spelling error. It's a simple switching of letters, happens to me all the time.
Thanks . Spellcheck should have picked it up. - I really appreciate you letting me know. Changing it now
Glad to be of service.


twister6 Reviews
Headphoneus Supremus
Pros: quality all metal shell, nice cable with in-line remote/mic, budget friendly price.
Cons: way too much bass, veiled “vacuum tube” sound.

I would like to Thank T-Peos/TGD for providing a review sample in exchange for my honest opinion.
Manufacturer website: http://www.startgd.com/rasiel/
* click on images to expand

The last time I reviewed a pair of monitors from T-Peos, I was looking at their budget Baguette model which I found to have a pretty good value, considering being priced at $69.  Fast forward one year, and I'm looking at yet another budget offering from this South Korean manufacturer who is well known for their multi-driver hybrid IEMs.  Actually, prior to receiving a review sample of Rasiel, I didn't even know that a price of this IEM going to hit another low, down to $40 (expected retail price).  But I did know it's going to have a warm and bassy sound, or as I was warned - vacuum tube sound.  That's what really intrigued me about these earphones, considering I don't listen anymore to basshead or warm/saturated sound monitors.  So, was Rasiel able to convince me with its "killing sound" to join the dark side?  Let's find out.
Unboxing and Accessories.
Despite its budget price which in some cases means cutting corners, the packaging presentation was actually pretty nice.  I found a glossy box with info in both English and Korean, going over the spec, some of the design details, and with a plastic display window showcasing the shells.  Out of the box, you quickly realize that you are not dealing with another premium Altone model, but rather an entree level pair with a very basic selection of accessories.  As a matter of fact, my review unit arrived only with 3 pairs of silicone eartips (S/M/L, good quality) and a pair of medium size Comply T200 tips, while the packaging box mentioned a fabric drawstring pouch and a shirt clip (pouch and clip were not included in my box).
Typically, there are no high expectations when dealing with a budget pair of IEMs, but if you take into consideration the listed accessories and packaging presentation - it was not bad for $40.  Also, the name "T-Peos" was not mentioned anywhere on the box, instead they used a name TGD where apparently both are a part of the same company, just an alternative name for different global releases.
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I usually dedicate a separate review section to a cable when dealing with a removable type, but here it's a bit of a different story.  No, cable is not removable, but it really is of a premium quality.  Being quiet familiar with Altone series and Baguette, I quickly recognized a familiar shape of the right angle headphone jack with a nice strain relief, a sturdy y-splitter with a good strain relief, and an oversized in-line remote w/mic on the right side of the cable after the splitter.
All these elements of the cable design were similar to other T-Peos models, except for one noticeable change – the cable jacket.  Anybody familiar with Altone models will recall how springy their cable is, memory effect due to a rather stiff sleeve-jacket covering twisted wires (2 separate conductors twisted from each earpiece, and all 4 inner-twisted going down to headphone jack after the splitter).  Looks like T-Peos has been listening to their customers feedback, and made some improvements to the cable design.  The twisted pairs going down from each earpiece now have a soft pliable shrink jacket which is great in keeping microphonics away, and after the y-splitter you’re no longer dealing with any sleeve - just inner-twisted 4 conductors, keeping the cable naturally soft and pliable.  I personally like this a lot better, and it looks great too.
In-line remote is universal with a single multi function button for play/pause/call, track skip control, and with a mic on the back of the remote to carry on phone conversation.  It looks identical to the remote used in the latest Altone cables with an easy to handle shape and a large button in the middle.  This button works with both Android and iOS devices, but I still find it a bit too bulky and would have preferred to see something along the lines of y-splitter shape to match its compact design.  But either way, it’s not a showstopper and rather a matter of a personal preference.  Also, there is a short but effective strain relief where cable attaches to the shell of earpieces.
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The design of Rasiel was another surprise which I didn't expect from a budget IEM.  Even higher priced Baguette had a plastic shell, while Rasiel features an all metal solid construction with 10mm single dynamic driver stuffed inside of a vase-shaped shell.  You will find a single vent port facing down behind the cable strain relief, and also a short nozzle with a lip which helps by keeping eartips from slipping off.  It also explains why T-Peos decided to include eartips with a longer core stem, to compensate for a shorter nozzle.
The right shell has an etched "R" marking while the left one has TGD logo.  This is not the best L/R id for symmetrical shells when you are fumbling in the dark, but in-line remote on the right side comes in handy to ID the sides.  Also, in terms of the fit, you can wear Rasiel either wire down or wire up, though I preferred a more traditional wire down where it felt more secure that way.  Typically I prefer to use cable cinch with a wire up fit, but cinch is not available here due to in-line remote.
In terms of an internal design, 110 dB sensitivity was about average and relatively efficient for these dynamic IEMs, but 8 ohm impedance is where they get you with some hissing.  Again, not exactly a show stopper since we are not dealing with high sensitivity where hissing level can get high, but still noticeable (mild) with most of my sources.
Overall, between the all metal slick design and a quality cable with in-line remote/mic, Rasiel doesn't feel like a budget IEM, and rather looks and feels like a pair of monitors that would cost at least twice its price.
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The fit.
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Sound analysis.
In many of my budget IEM reviews the unboxing and the design section starts off with a down beat until I get to a sound analysis which sometime redeems earphones with an unexpected good sound quality.  Unfortunately, this write up is going to be reversed with an upbeat intro about the design and the cable, and then a nose dive once I get to a sound analysis.  I went back'n'forth, thinking that as a reviewer I have to be open minded when I come across a sound which is not my cup of tea.  But that pep talk didn't help.  No matter how much I tried switching between different sources or playing with EQ, I couldn't get into the sound grove of the Rasiel.
I don't have any vacuum tube amps to test their effect when paired up with IEMs, and T-Peos describes its tonality as "filled with the sound of vacuum tube” - clearly not my cup of a warm tea or a chicken soup.  The sound signature is very much V-shaped, on a borderline of being L-shaped with upper mids and treble buried under a thick saturated bass blanket of a warm smooth and a bit muted tonality. 
Low end has a deep sub-bass extension with a powerful rumble and a massive mid-bass hump that hits you hard (yet, slow) with a big hollow punch.  Bass is not well controlled and spills into the lower mids, making them thick and muddy, and overpowering the rest of the spectrum with a veiled blanket.  Surprisingly, I can still hear the upper mids which are coming through with a nice organic tonality, and you can direct your focus to zoom into a treble with an ok definition, though it quickly rolls off with a poor extension.  Unfortunately, the bass is so messy that it just overpowers everything, and it's not just the mid-bass but also the sub-bass.  And with such signature and tonality, you also get a soundstage with sub-par average performance in all 3 directions, making sound more boxed in and intimate.
I tried adjusting the EQ, using PAW Gold Parametric EQ which gives you more control, but still wasn't able to tailor the sound to my personal liking.  Also, I don’t have any other similar signature IEMs for a comparison like I usually do in my other reviews.
I really hate to end this review on a sour note because I'm sure there will be people who are going to enjoy this type of bassy saturated "vacuum tube" sound.  I have no doubt a lot of thought went into the tuning to achieve Rasiel target sound signature.  Also, some might question why even bother writing a review if I don't like the sound?  Well, as I mentioned before, this is still a decent quality IEM with a very budget friendly price.   I believe their sound tuning will have a polarizing effect where some might hate it while other will find it to be fun.  So if you are into this type of sound signature, and want a pair of IEMs with a thick hard-hitting powerful bass where the retrieval of details or treble sparkle is not your highest priority - you will probably going to enjoy the Rasiel.
@Brooko - thank you for confirmation, Paul!  That was puzzling for me as well since I noticed other reviewers enjoyed Rasiel a lot more than I did, thus i tried to take my personal biased preference out of the equation, thinking it's just me :)  My opinion is definitely solid on 3.5 stars, and I'm going to update my review now to reflect that.  What bothers me the most with their tuning, in this particular case I wasn't successful in cleaning up the bloat with EQ, even using a precise parametric eq and dsp effects of PAW Gold.  Other than that, I actually like the design and the cable improvement.
Yeah - the build is great. In fact better than great for the price. I'm playing with EQ at the moment.  If you get enough of the bass out of it, there is a really nice mid-range hiding back there.  Worth perservering with actually.
waynes world
waynes world
Your reviews are great. Thanks again.


500+ Head-Fier
Pros: Well built and fun sounding earphone.
Cons: Details can be a little sparse. Mic/button feels a little cheap compared to the rest of the design.

T-PEOS is known for their creativity and at times unique sound.  They have truly been pioneers in the hybrid market.  Now they come to the stage with their first “vacuum tube” technology.  Admittedly, I have been out of the game for a few months (life happens but I’m back), but I had never heard of vacuum tube earphones before.  So when I was contacted by James Park from T-PEOS about these earphones I immediately jumped on the chance to test them out.  T-PEOS provides this review sample to me in exchange for my unbiased opinion.
Driver Unit : Woofer driver 10mm
Impedance : 10Ω ±15%
Sensitivity : 110 ± 2dB (At 1kHz)
Power : 3mW / 20mW(nom/Max)
Frequency Response : 20Hz ~20kHz
Connector : 3.5mm / 24k Gold plating plug
Cord : 1.2M Twist cable / Y-type
Weight : 7g (Without Cable)
Source: ibasso DX50 & iPhone 6 Plus
Accessories & Packaging:
Packaging and accessories are nothing to write home about here.  Yet at this price point it is par for the course.  The Rasiel come in a glossy cardboard box with the Brand TGD and the subtitle “Killing Sound.” I suspect that this is a translation error and instead they meant “killer sound.”  Rasiel is much closer to killer sound than killing sound for certain. 

Inside you are presented with the beautifully designed earphones themselves as well as a basic selection of tips. 


S/M/L size of silicone tips as well as a pair of medium comply T-400.  The box itself mentions a pouch and shirt clip but unfortunately my review unit did not come with these extras.

Build Quality & Fit:
Wow! This build quality is truly exceptional at this price point. Upon first look at these I immediately thought of Final Audio Design and their Piano Forte. An IEM that I doubt I will ever have the opportunity to listen to.  The Rasiel is an absolutely awesome earphone to look at with that beautiful chrome coated brass body.  I have not come across a better looking earphone at this price point.  The cable is braided and I experienced zero microphonics during my many listening sessions with these.  The cable also did not tangle easily which is something that I am grateful for considering my review unit did not come with any sort of case or carrying pouch.  The cable itself is terminated with a right angle 3.5mm jack.  The cable also includes a one button mic control for use with mobile devices if you are in to that sort of thing.  Admittedly, the mic/button feels a little cheap compared to the rest of the earphone.  Unfortunately, these do not come with with a cable cinch which I feel would be a good addition.  Yet at the $40 price point it is an acceptable omission. 
I do not foresee fit being an issue for most consumers especially with the included comply tips.  I myself had a little trouble maintaining a seal with the supplied silicone tips.  Once I switched to the comply foams seal was instant and consistent.  Removing the Rasiel from your ears can be a little trickier than your average earphone given the ergonomics of the design.  Overall, these are a well-designed and very comfortable headphone to use even for someone like me with small ear canals.
 To put it simply I find the T-PEOS Rasiel to be a very fun sounding earphone.  At this price point I do not have high expectations for clarity, instrument separation, or tight bass.  Yet the Rasiel do better than anything I have heard in this price range. Switching back and forth between the Rasiel and the Fidue A31s I am immediately left with a feeling of wanting more from my Fidue’s.  The Rasiel just sounds fuller and more powerful.  Perhaps that has to do with the powerful bass that these are packing.  Man these certainly pack a punch! 
Lows: The lows on the Rasiel are certainly boosted.  Bass is powerful and fun.  This can make it quite enjoyable for certain types of music.  As is usually the case in this price range quantity is valued over quality.  The Rasiel delivers bass quantity in spades.  Bass quality is above average at this price range and provides a fun experience.  The bass slams pretty hard and isn’t quite as tight and has a slower decay than earphones in the $100+ price range. Then again these are less than half of that price.  Mid-bass is king here with sub-bass taking a back seat.  You are going to hear it more than you are going to feel it with these earphones.  The rumble is not as powerful as the slam. 
Mids: While not the star of the show mids are certainly present and accounted for in the Rasiel.  The bass clearly is the star and at times can bleed into the midrange but once again the Rasiel are above average for budget/mid-fi.  Vocals sound fine but I must admit I was left wanting when listening to Mumford & Sons and The Avett Brothers. Overall they are suitable for the price range.
Highs: The highs of the Rasiel are somewhat crisp but don’t expect a ton of detail out of these.  You simply will not get huge amounts of clarity and analytical sound in this price range and that is certainly true of the Rasiel.  Those looking for bright sparkly treble will be disappointed as these tend to be a warmer sounding earphone.  Though admittedly I did enjoy them thoroughly with electronic and pop music.
Presentation: If you are used to higher end earphones you may be a little disappointed in the instrument separation of these.  Things can get a little muddled and dragged out with speedier songs.  Once again this makes sense given its price point.  Soundstage is pretty good but you definitely still get that “in your head” feel from these.  With that said I do not get a congested sound from these and I was happy with the presentation that Rasiel has to offer.
It really is all about what you want out of your earphone.  If you are not looking for a neutral or analytical earphone but instead want something you can jam to on the bus and on the go than these are for you.  I really enjoyed these with pop and electronic music and I imagine that they would work great for hip-hop as well.  However, for classical and rock music I myself might look at other options.  Overall, I feel that at this price point the Rasiel offer great bang for your buck and I will happily recommend these to everyone looking for fun sound at a great price!

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Headphoneus Supremus
Pros: Solid build, great look, decent comfort, great SQ once EQed
Cons: Not so great SQ before EQ.
Read the full review here!


Sponsor: iFi Audio
Formerly with Unique Melody
Pros: Solid Build, Great Cable, Good midrange and treble
Cons: Lacking accessories, Somewhat diffuse bass
T-PEOS is a company that I have some degree of familiarity with. They seem to be a company targeted towards the lower-mid budget market with offerings that seem to focus on a generous amount of bass. I got the opportunity to test and review the Altone 250 about a year ago and, honestly, I didn’t view it in the most positive light. I’m happy to say that the Rasiel is a bit of a different story.
I was approached by James Park, who is, from what I know, a relatively new representative for T-PEOS. James introduced me to what they called their new “Vacuum Tube Earphone.” Interested in hearing what they mean by this, James arranged for a review unit to be sent to me.
Packaging and Accessories:
The Rasiel arrived at my doorstep much sooner than I had anticipated. The people over at T-PEOS certainly move fast. The packaging isn’t anything to be wowed by but it’s certainly nice. There are a lot of sub 100 dollar earphones out there that pretty much has a non-existent presentation of their product. The Rasiel comes in a gloss black box that displays the earphones in the front and some details about it in the back. While I would say the packaging isn’t quite on the level of what Brainwavz offers, I’d certainly give it a passable grade. The packaging has a nice presentation to it and protects the Rasiel well. That’s more than enough for me when it comes to an earphone that’s 40 dollars.
The accessories that come with the Rasiel are pretty bare-boned. The earphone comes with 3 pairs of silicone tips of S/M/L sizes as well as a set of comply tips. That’s pretty much it. I would have loved to see some sort of pouch or even a softshell case, but unfortunately that’s not the case. Something like a shirt clip would also have been a very nice thing to have. Again, considering the price, it’s not the end of the world, but these little things can certainly make a product feel more well-rounded or premium.
Packaging of the Rasiel
Build, Design, and Comfort:
The second I glanced at the Rasiel, and it immediately reminded me of the Piano Forte series from Final. The unique horn speaker design seems to be one that quite a few companies have tried their hands at. I'm a fan.
When it comes to build quality, the Rasiel might just take the prize for the most well-built earphone I’ve had the pleasure of testing in the sub 100 dollar price range. The earpieces are made of a glossy metal material that feels very solid. The right/left indicators is a little interesting in that the right piece has an R etched on it while the left piece has the company’s logo etched on it. Once you realize this, it’s certainly not a problem. However, I definitely spent a solid minute awkwardly staring at the left earpiece trying to figure out if it’s the right or the left. The housing also has a vented port for the drivers. From my experience, it doesn’t seem to affect the isolation too much. The isolation is good and comparable to the level of isolation you’ll find in other earphones.
The Fantastic Solid Housing of the Rasiel
Back when I reviewed the Altone 250, I had a whole lot to complain about with the cable. It kind of sucks a lot. My experience with the Rasiel’s cable is a complete 180 degree turn. Like the cable of the Altone 250, the cable has a bit of a rubbery texture to it and a nice metal Y-split. That’s about it as far as similarities go. Below the Y-split is a very tightly braided quad-braid. It’s certainly a breath of fresh air compared to a lot of the other cables that other companies offer with their lower priced products. The cable feels solid and is very manageable. It also doesn’t retain too much memory but can be a little bit prone to tangling due to its rubbery exterior. Above the Y-split, the cable has a thin plastic covering over the dual twist of the cable - I’m guessing to prevent the twist from unwinding. The 3.5mm jack is a nice 90 degree angle metal piece with some strain relief. There is also some strain relief between the housing and the cable, but again, nothing overly protective.
I have 2 small complaints regarding the cable of the Rasiel though. The first is that T-PEOS still hasn’t included a chin slider. This is where that shirt clip might come in handy. The other is that the cable noise is still somewhat noticeable. Much improved from the Altone 250, but still a bit of an issue for me. Again, maybe that shirt clip would come in handy right about now.
The Rasiel also features a 1 button control talk remote which is, interesting, probably the most plastic-y part of the earphone. The housing of it is a blend of metal and plastic with the button being plastic. The button has a nice click to it, but overall, the remote doesn’t exactly exude the feeling of quality like the way other aspect of the product does, and feels a little out of place.
The Remote (Sorry the button is a little hard to see)
In terms of fit and comfort, the Rasiel fits easily and very well. Despite having a bit of weight to it due to its metal housing, it doesn’t fall out of my ears as a result. The issue I have with the overall comfort of the Rasiel doesn’t come from the earphone itself, but from its ear tips. To me, they’re just a bit too stiff. With a quick and easy switch of the tips, you can have a very comfortable earphone that you can keep in your ears for hours without any issues.
Sound Impressions:
Like with almost all of my other IEMs these days, listening of the Rasiel was done with my Lotoo PAW Gold. Yes, I listened to a 40 dollar IEM with a 1600 dollar player. The LPG is a player I’ve become very familiar with and using it for all my IEM listening at least removes one variable from the equation.
The bass on the Rasiel is big. Right off the bat, this is not a product for those looking for a reference sound. But then again, why would you look for a reference sound from a 40 dollar earphone? Bass hits are authoritative, heavy, but somewhat diffuse with a generous about of mid bass bump and some roll off in the sub bass. Sub bass texture is also somewhat lacking, but as an overall package, I think the bass performance is actually fairly good for the price and its bass heavy presentation. Bass hits still have a focal point of impact and, while the heavy low end certainly affects the midrange a bit, I think it’s acceptable and certainly not as bad as some other more budget oriented products I’ve heard.
The hefty low end emphasis certainly exhibits itself into the lower midrange. The lower midrange is a bit thick and certain vocal syllables can be emphasized and resonate a bit oddly as a result. Compared to the lower midrange, the upper midrange is a good bit more relaxed. Overall, vocals are fairly laid back and but a good sense of warmth to them. While I personally feel that the midrange isn’t particularly engaging and a little too shy, I think the Rasiel has one of the better midrange presentation at this price point. Overall detail and resolution is honestly not bad, and while the timbre is still overly warm, it’s one of the more natural sounding I’ve come across. Yes when I first listen to it, it’s a little wonky, but it’s something that my ears can adjust to. There are a lot of in ears at this price where no matter how much time I spend with it, it just flat out sounds wrong.
The treble response of the Rasiel is fatigue-free, smooth, but respectably well-textured and quick. Actually, the treble surprised me quite a bit. It tends to get lost a bit when the bass starts to take over since it’s fairly polite, but it always manages maintain itself with a good sense of crispness. It’s when the low end takes a break, though, that you actually realize the treble’s pretty good. In terms of overall quantity, I would probably ask for a bit more as you don’t really get too much shimmer or sparkle out of it. Those in favor of a smooth treble will be happy with what it has to offer.
Overall soundstage of the Rasiel is not bad, but what does deserve some snaps is the separation and imaging. The lower end does smear a bit and isn’t particularly well-separated, but the midrange and treble has some impressive separation. The soundstage is certainly not expansive, but it does present the sound in a way that’s not claustrophobic and completely in your head. I was actually happy to hear that the Rasiel does have some degree of layering to its sound, which is not something you see too often in this price range.
The Rasiel
Final Thoughts:
There are some absolutely monstrous IEMs in the sub 100 dollars market today – maybe even sub 50 dollars. The Rasiel is, well, not one of them. Compared to some absolutely amazing IEMs like the Zero Audio Tenore, Shozy Zero, or the modified Fostex TE-02n I recently heard (which is probably one of the most natural sounding IEMs I’ve heard below 500 dollars), the Rasiel certainly doesn’t stack up. But that’s also because the Rasiel offers something very different. If you’re looking for something that’ll give you almost as good of a sound as your audiophile setup but on-the-go to places you might not want to bring your expensive gear to, then I would certainly suggest one of those products to you. But for those who just want to feel the bass pump or for those that’s not looking for that flat sound signature, the T-PEOS Rasiel is one of the IEMs that does a better job than most.
Pros: Pretty buds. Much junk in that trunk kinda bass. Fab cable.
Cons: Bass is subtle like a sledge hammer to the face. Upper end detail is a little diffuse.
T-PEOS RASIEL Quick Review by mark2410
Thanks to T-PEOS for the sample.
Full review here http://www.head-fi.org/t/807332/t-peos-rasiel-review-by-mark2410
Brief:  Finder X1 lookalikes.
Price:  I am told they are expected to retail for circa US$40, which is about £27.
Specifications:  Driver Unit: Dynamic driver 10mm, Impedance 8 ohms, Sensitivity: 110+/-15%, Power: 3mW / 20mW, Frequency Response: 20Hz to 15kHz, Weight 8g, Cord: 1.2m Twisted.
Accessories:  3 pair of silicone tips, a pair of Comply’s, a shirt clip and a “fabric pouch.”
Build Quality:  The buds are solid metal, chrome plated brass apparently, they look quite nicely put together and especially that braided cable.  It’s all rather good for the price.
Isolation:  They, unusually for a dynamic, are sealed it would seem and thus they actually isolate, isolate pretty well too.  You could easily get away with using them for most activities, the Tube and long flights are still a bit much but you could survive with them.  More than easily enough to get yourself run over if you stop looking where you going.
Comfort/Fit:  On both counts they were very good.  I had no trouble at all with them worn up or down.
Aesthetics:  I look at them and I can’t help think Finder X1.  It’s that same colouring, bare metal, inverse trumpet, tapering shape that makes them had to grip when removing.  The buds and the cable both look highly attractive to me.
Sound:  These are on the whole, when weighed back and forth, are all about the bass.  They are not the deepest unless well powered, they however can pump out a tremendous amount of vigour.  Big beastly roawwwwrrrrrrrrr kinda bass is going on here.  They truly love nothing more than encountering some pop, bass cannon fodder music so they can let rip.  They have much junk in their trunk and they aren’t afraid to wave it up in “yo face.”  Okay so I’m not much with that sort of colloquialism but I’m sure you get my meaning.  They are big in the bottom and they love to show it off to all and sundry.  It’s fun, a little bit over eager perhaps but it’s still just damn good fun.  It a bit of a hump, it’s a little bit disjointed and separate from the mids.  Not unlike a 2.1 system with a moderately sized sub that can’t go all the way down so has a big hump of it.  That big hump then stands out a bit from where it mixes with the midrange.  It feels a touch out of step but its goodly entertaining.  The gap however that puts some space between the bass and the vocals so vocals don’t sound unduly influenced by that bass.  Mids start rather clearly distinct and separate.  They aren’t bad mids either, somewhat behind the quantity of bass but its overall W shaped sound signature leaves them more unencumbered than the bass quantity would suggest should be.  It’s good.  The treble, it’s got a bit of distance too and it is not bad for detail but it’s really rather more subtle about it.  There is a little peak from time to time at volume and when amped but mostly it’s a light wash of shimmer.  No crisp hard edges anywhere that I noticed.
Value:  A W shaped, bottom end slanted, big bassy, consumer friendly sound that’s rather good looking and have a nice cable too.  What’s not to like for US$40?
Pro’s:  Pretty buds.  Much junk in that trunk kinda bass.  Fab cable.
Con’s:  Bass is subtle like a sledge hammer to the face.  Upper end detail is a little diffuse.
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