This mini review is actually a small part of a larger review/thread covering all of the T-Peos Altone series. Here is a link to the review:
 
http://www.head-fi.org/t/774084/t-peos-altone-series-thread#post_11751591
 
T-Peos Altone 350 ($379 on CTC Audio’s website)
http://www.ctcaudio.com/collections/t-peos/products/t-peos-altone-350-3-way-hybrid-earphones

 
The 350 carries a similar package to the 250, with titanium housings and the same cable options. You get two cables (one with a single button microphone in black and a red cable with not mic/remote). The 350 takes things a step further with more tips to choose from and a high qualtiy leather case to hold everything.
 
The 350 takes a road less traveled in the IEM world. If you are sensitive to treble, STAY AWAY! Without an EQ adjustment, the Altone 350 are flat out sibilant in my opinion. Your mileage may vary, just be warned that these are not for those sensitive to forward treble response.
 
The Altone 350 is a triple hybrid design with a 10mm HPS driver and two Knowles armature drivers playing the high frequencies. They really do have a dynamic tuning that provide a level of timbre that the others don’t (with the exception of the 250 being relatively close). Everything plays with fantastic resolution and clarity, but the tuning is not neutral or natural to my ears. There is a boost in the mid bass range. While it doesn’t bleed or overshadow the sound like the Altone 250, it is very forward and sounds unnatural to me. There is also the previously mentioned Treble boost that jumps out in front of the rest of the mix.
 
I will go as far as say that these are different from the pack and some will really like them for what they are. What they are not is neutral or natural sounding. If you want a very aggressive tuning with enhanced dynamics these are right up your alley. Their dynamic tuning and resolution will impress those who are looking for this type of sound.

INTRODUCTION

My first experience with T-Peos was almost a year 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 sonics – 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 Altones from T-Peos (although I could have kept them as a review pair).
 
For anyone who hasn’t heard of T-Peos, the parent company SWP Shinwoo (http://swpshinwoo.com/) 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 T-Peos Altone 200. The commitment to build quality continues with the Altone 350.
 
DISCLAIMER
 
I was provided the Altone 350 as part of a tour organised by CTC Audio through CTC Head-Fi Sponsor Empj and facilitated by veteran Head-Fier [b]svyr[/b].  The tour unit will continue back to Australia at the completion of this review.  I am in no way affiliated with T-Peos, or CTC Audio - and this review is my honest opinion of the Altone 350.  I would like to thank (again) svyr and Empj for making this opportunity available.
 
I’ve now spent a 7 days with the Altone 350, and have around 20-25 hours listening time with them. Normally I would like to take a minimum of 10-14 days before I write a review/impression – but owing to tour restrictions, 1 week is the maximum time I could dedicate to the review.  I do feel I have a good idea of the strengths and weaknesses of the Altone 350 in that time though.
 
PREAMBLE - 'ABOUT ME'.   (or a base-line for interpreting my thoughts and bias)
 
I'm a 48 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 (Fiio X5, X3ii, X1 and iPhone 5S) to my desk-top's set-up (PC > USB > iFi iDSD).  I also use a portable set-up at work – either X5/X3ii > HP, or PC > E17K > HP.  My main full sized headphones at the time of writing are the Beyer T1 and Sennheiser HD600.  Most of my portable listening is done with IEMs - and up till now it has mainly been with the Fidue A83, Dunu Titan, Trinity Delta, and DUNU DN-2000J. 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 extensively tested myself (abx) and I find aac256 or higher to be completely transparent.  I do use exclusively redbook 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 48, my hearing is less than perfect.
 
I’ve used the Altone 350  from a variety of sources, but for this review, I’ve mainly used it with the iDSD, X1+E11K combo, and straight from the headphone-out socket of my Fiio X3ii and also my iPhone 5S.  Although I have tested them with an amplifier, I do not think they benefit from additional amplification.  In the time I have spent with the Altone 350, I have noticed no change in the overall sonic presentation.  I am not worried about burn-in for the purposes of this review as they are a tour unit and have already clocked up at least a 100+ hours during the period of the tour.
 
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 REVIEW

PACKAGING AND ACCESSORIES          
 
The Altone 350 arrived in a retail box, in two tone grey and reddish orange. The box is reasonably smart looking with a picture of the Altone 350 on the front, and a list of specifications and accessories on the rear.
 
 
Opening the outer packaging reveals a black inner box with a bright yellow windowed tray cover over a moulded foam tray which snugly houses the Altone 350s.  Lifting this foam tray then reveals a second clear plastic tray which houses the accessories.
 
 

The accessories are generous and well thought out, and include:

1. 3 pairs of hybrid tips (two tone)
2. 3 pairs of standard silicone tips
3. 3 pairs of dual flange tips
4. 1 pair of genuine Comply Tx200 medium tips
5. 2 detachable cables – one with mic, and one without
6. 1 x 3.5-6.3 mm jack adaptor
7. One shirt clip
8. One pair of ear guides
9. One warranty card (printed in Korean only)
10. One zipped leather carry case

 
 

The quality of the accessories is very good – and especially so the case which does appear to be leather with a good quality zip and 2 compartments (although the divider does not actually go all the way to the bottom.
There is a good variety of tips to suit most ears, and I like the inclusion of the short dual flanges as an option.
 
 

The shirt clip is the mechanical type, very well engineered, and although reasonably large – does it’s job well. The ear hooks are the generic rubber type with a split to insert the cable, and as you’ll see later in the review, quickly became the most essential accessory in the entire package for me.
 
TECHNICAL SPECIFICATIONS
 
(From T-Peos)
 
FREQUENCY GRAPH
 
There are some graphs out there of the Altone 350 already – but as I wanted to compare them directly to my Altone 200 and DUNU DN-2000J, I decided to measure them myself.  It takes a little more work – but gives me a better baseline for understanding what I’m hearing.
 
To do this, I used a calibrated SPL meter (not an iPhone app – proper meter), measured using the C weighting, and then translated to adjusted dB levels (ie what we would actually perceive).  This is done by set formula, and I would like to shout out to @twj321 (for providing the spreadsheet and formulae) and @DJScope (for helping me format the graphs). I used a louder than normal listening level and set tones – so I could measure accurately and be above the noise floor.  All readings were checked twice.
 
So here are the measurements for the Altone 350 (after conversion), and below is the graph. A graph comparing the Altone 350 to the 200 and Dunu DN-2000J is posted later in the review.
 
 

 
What I’m actually hearing is a very a clear mid-range, but without excessive treble sparkle, and a very prominent low end.  Treble response is quite well managed, but there are signs of a sibilant peak which very occasionally shows itself with some vocals.
 
BUILD QUALITY / DESIGN / MICROPHONICS
 
The Altone 350 is in a word – “solid”.  It has a traditional bullet design, with a two piece all titanium shell (with black plastic accents/inserts).  Each shell measures 22mm from base to tip, and has a circumference of 12mm at its widest point.  The nozzle is 5mm long and the lip is a little over 5mm wide. The nozzle itself has a black filter mesh at its end. The shells are relatively smooth, and comfortable to wear.
 
 

The connectors for the Altone 350 are the new DC connectors, and on this unit, they feel both sturdy and snug.  As far as overall durability goes – I like these a lot more as a connector than the mmcx.  There are L and R markings on the shell, and also the plug. The shells are easily identifiable though as the right is red and the left is black. One of the issues of seen with this unit though is that the paintwork (rings) on the IEMs is actually coming off. Not the best craftsmanship on a flagship earphone. The DC connectors have good relief below the actual plug.
 
 

The cable is a twisted pair on each side going to a larger twisted four below the Y split. The black cable has a single button microphone above the Y split.  This works well with the iPhone (single push play/pause, 2 pushes next track, 3 pushes previous track).  The microphone is relatively clear on this unit, and hangs just above my chin (cable over ear), and about 70mm below it (cable down).  The red cable has no microphone or push button unit. Both Y splits are tubular with good relief.  Sadly the red cable does not have a cinch (huge omission IMHO). Both cables terminate in 3.5mm right angle gold plated jacks – the black with a 4 pole jack, and the red with a traditional 3 pole. Both Jacks have very good strain relief.
 
 

Both cables are IMO a little over engineered, prone to memory (the red kinks really badly) and are pretty microphonics. The black cable seems to be a little more pliable, and I can wear it over ear without any guides.  The red is very unruly, and I have to wear guides to get it to stay.  A simple cinch is all that is needed.
 
 

FIT / COMFORT / ISOLATION
 
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.  Rather than trying the included tips (remembering it is a loaner unit), I instead went to my faithful Sony Isolation tips (perfect fit for me).  There was no driver flex and a really good seal.
 
Spin-fits, also fit well, as did most of the various tips I tried – including spiral dots, Ostry tips and Complys (T400s actually fit pretty well – although T-Peos do include Tx200s). The most consistent, comfortable and best seal was with the Sony Isolations though, so I used these throughout the review.
 
 

Comfort and fit are both pretty good over ear, but the unruliness of the cable does mean that if you’re going to be doing anything physical, you’ll want to fit the ear guides. These work pretty well, but can get frustrating at times.  By far the biggest gripe I have is with the red cable.  A simple cinch is all that is needed (you have one on the Altone200 T-Peos!), so why they omitted this is beyond me.  For an over ear cable wearer – the red cable is just a nightmare without one.
 
Isolation though is very good for a hybrid.  Although I’ve looked for a vent, I can’t find one – and there is no driver flex for me so far.  So if they have managed to avoid a port – well done. It’s not going to isolate as good as Shure, but it is as good as I have had with a hybrid so far.
 
SOUND QUALITY
 
The following is what I hear from the Altone 350.  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 and iDSD as source, and Sony Isolation tips.
 
Tracks used were across a variety of genres – and can be viewed in this list http://www.head-fi.org/a/brookos-test-tracks.
 
Thoughts on Default Signature
T-Peos house sound for me so far has often been V shaped.  I was hoping to get the same clarity as the Altone200, and maybe a little less quantity but more quality with the bass.  This does not describe the Altone 350.
The Altone 350 does possess an extremely clear mid-range and lower treble, but sadly both mid-bass and sub bass are both a lot more prominent than the Altone 200. The lower treble has been shelved a little, so it isn’t too peaky, and most of the time delivers consistently clear detail – but there is a secondary peak in the 8-10 kHz range which sadly does hit a little sibilance with some of my female artists.
 
So what we end up with is a very clear overall signature – but with quite a boomy bottom end.
 
Overall Detail / Clarity
No issues with detail in my usual go-to tracks (“Gaucho” and “Sultans of Swing”). Cymbals are clean and clear, micro detail is good, nice guitar crunch, and yet vocals are still nicely presented.  My issue is predominantly with bass.  In Sultans, the bass guitar dominates, and after a while the track becomes a little monotonous.
 
Sound-stage & Imaging
The Altone 350, despite its bassier tuning, actually exhibits a reasonable sense of space with Amber Rubarth’s “Tundra” – just bordering on out of head. I’m not sure if this is related to come of the slower decay in the bass notes. The imaging is OK – but the bass does tend to take away from the crystal clear mid-range a little. Directional cues are average, but pretty consistent.
 
McKennitt’s “Dante’s Prayer”was up next, and the overall presentation was pretty good. McKennit’s vocals were maybe just a little too subdued (compared to other more balanced headphones), but piano and cello were very good in tonality and texture, and the whole track blended well. With the applause at the end of this track, there was a slight feeling of connection with the crowd though – so the sense of width and depth is not bad for an IEM.
My last test was with Amanda Marshall’s “Let It Rain” and this presentation was really good. This track does tend to be slightly brighter in presentation, so this suited the Altone 350 well – and the naturally holographic sense of the recording came through wonderfully. This was one of the moments that the Altone 350’s shone during my time with them.
 
Bass Quality and Quantity
By now I knew the Altone 350 could deliver on bass quantity – but how was its overall quality? Mark Lanegan’s “Bleeding Muddy Waters” was interesting, because there was plenty of thump, but to be honest I wasn’t particularly impressed by the overall quality.  Just a lot of mid-bass thump, and no real definition to it.  Mark’s voice had great timbre, and tone though.  Switching to Lorde’s “Royals” took the Altone 350 impressively low and once again that huge impact was very present. When the bass guitar kicked in though, the depth of sub-bass was pretty impressive.  Too much for me though. Ella’s vocals were really clear, but the whole track was just too massively V shaped. Some may enjoy this – I’d want to EQ some bass out.
 
Female Vocals
Like the Altone 200, the Altone 350 has a mid-range which should be just perfect for female vocals, and I was looking forward to testing it. My first test is always Agnes Obel’s “Aventine” and the Altone 350 was really excellent with this track.  Vocals were sweet, clear and effortless, and the bass really performed well when the cello kicked in.  Thoroughly enjoyable.
 
London Grammar was equally as good.  Hannah’s voice had its usual magic, and once again the bass didn’t seem quite so onerous – still cavernous at times, but not obviously overpowering things.  So I played through my usual test tracks, and it was mostly very clean, very clear, and very dynamic. Feist at times was bordering on too much bass (and I don’t usually ever make that comment), but FaTM was very good, and Gabriella Cilmi’s “Safer”, which never fails to move me, had a real connection. Norah was her usual captivating, wonderful self (has that girl ever sounded bad for me on any headphone?), and I think it’s safe to say that I really like the Altone 350 with my female artists.
 
Male Vocals
You’d expect that the Altone 350 with its V shaped signature and combination of clarity and bass impact would really excel with a lot of my rock tracks – yet strangely this is where (at times) the excessive and unbalanced bass just got a little too much.
 
Male vocals were actually rendered pretty well among all my artists, but anything with a lot of bass guitar became slightly monotonous at times.  Some of my older classic rock – 10CC, Jethro Tull and the Eagles sounded brilliant – but whenever I got to anything slightly bass heavier (Alter Bridge, Green Day) I just wanted to grab an EQ and dial down the bottom end.
 
“Immortality” and “Keith Don’t Go” are both acoustic tracks which were presented wonderfully by the Altone 350, and the one thing I noticed with both was that with the absence of bass guitar, the midrange had a chance to really shine.
 
My litmus test is always Pearl Jam. This was pretty good overall, great detail, and plenty of cymbal and snare action.  Eddy’s voice was its usual magic – but again, if I could chop that bass guitar back just a little ……
 
Genre Specific Notes
For Rock and Alt Rock – the Altone 350 was a little hit and miss.  Plenty of dynamics for the most part, and I was impressed time and time again with how clear the mid-range was despite the overpowering bass.  Floyds “Money” was stunningly clear, but sadly the detail was again overshadowed by the bass guitar. PT’s “Trains” was also pretty good – but again that bass – what were T-Peos thinking with this tuning?
 
For Jazz, Blues and Bluegrass, it was a hit and miss affair dependent on the artist.  Portico Quartet was good up to a point, but even the double bass got to me after a while. Yet Miles as a lot better - the combination of trumpet, cymbals and a mellower double bass playing style was quite pleasant. Dust Bowl Children was really good – with the banjo and guitars able to shine (loving that mid-range), but switching to Beth Hart’s “Lifts You Up” (which is recorded a little hot) brought the sibilant peak into play – almost eye watering. Bonamassa in contrast was really good – just not as dynamic as I’ve heard it on an IEM like the 2000J.
 
Rap, Trance and EDM was where I expected the Altone 350 to come into its own, and to be fair, lovers of these genres may well be impressed with the Altone – but again I found them simply too bass heavy. I’d enjoy the first 30 seconds or so of each track, then after a while the bass monotony would kick in and just leave me overloaded.  I really enjoy the EDM I do own, but not with the Altone 350.  The most enjoyable “electronic” track in my rotation ended up being The Flashbulb – and I’m pretty sure this was simply because it’s not an overly bass heavy track.  In fact I could listen to both of TF’s albums all the way through and have a thoroughly enjoyable time.
 
Pop and Indie fared a lot better but still a bit hit and miss for me.  Adele was really good (female vocalist, not bass heavy), but Coldplay’s “Speed of Sound” suffered from monotonous bass line kicking in again by about the 70% stage.  Band of Horses was brilliant - a really dynamic listening experience, but sadly with Wildlight’s “Dawn to Flight” – while Ayla’s vocals had their usual magic – again that lower and mid bass just ended up spoiling things for me.
 
Classical was surprisingly good – on everything I played, and particularly so with Netrebko & Garanca’s duet from Lakme.  Kempffs rendition of Beethoven’s Piano Sonatas was truly breath-taking, as was Zoe Keating’s performance with Cello.
 
AMPLIFICATION REQUIREMENTS
 
The Altone 350 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 iP5S I’m usually at a volume level of around 35-40%, and on the X3ii around 35/120.  I did try amping with the X1 and E17K, but noticed no obvious signs of improvement.
 
EQUALISATION
 
As you’ve probably noticed, the biggest issue I have with the Altone 350 at this stage is simply too much bass. So with the X3ii I applied a smiley shaped cut (centred around the mid-bass), and then revisited some of the tracks I’d previously had issues with. For my tastes, this is so much better, and so much easier on the ears.
 
COMPARISONS
 
I thought for this section I’d look at two differing points of comparison.  First I’ll look at T-Peos’ own Altone 200 – as it is also a triple hybrid, and should pose a natural question – did T-Peos actually improve with the new release? Secondly, we’ll look at DUNU’s current flagship – the DN-2000J and see where that sits comparatively.
 
I graphed all 3 – using test tones, a calibrated meter, and spreadsheet conversion program. The graph is below, and very much tells its own story
 

 
 
Altone 350 vs Altone 200

Both are triple hybrids.  Both are tuned to have quite a V shaped overall signature with emphasis in the bass and also in the upper mid-range.  Both are very clear IEMs.  Overall build quality would probably go to the 350 – but if we look at what is practical, I’d take the 200 every time.  Sonically the 200 is definitely thinner (comparatively) but next to the 350 seems a lot more cohesive and balanced. I never feel (with the 200) that I need to EQ the bass down. The 200 is also smaller and more comfortable to wear.  Whilst the cable isn’t detachable, it is better behaved (more pliable), and it has a cinch so it makes over ear wear easy. And most importantly it is around ½ the price of the Altone 350, and I personally think it sounds a lot better.
 
Altone 350 vs DUNU DN-2000J

Not everyone will like the 2000J  - it is relatively well balanced, with a brightish tilt to it. Compared to the Altone 350 – the build quality and accessory package is similar, and where it doesn’t have the replaceable cable, it does have a cinch and also innovations like the cable tidy. Sonically the bass quality on the DUNU kills the Altone – it’s not even close.  The DUNU has wonderful speed and texture, where the Altone just has quantity and a monotonous boom. Both are very clear through the mid-range, but I personally don’t find the DUNU quite as peaky in the upper end.  Value wise the DUNU is slightly cheaper – yet sonically (IMO) far superior to the Altone.
 
VALUE
 
The Altone 350 has a RRP of $379 on CTC’s website currently, but it’s a price I really struggle to see any value in.  It’s not overall a bad sounding IEM – and some will probably like its default tuning.  But it’s not the sort of tuning you expect in a flagship – especially when the IEM it is essentially replacing is cheaper, but an arguably better overall proposition.
If you’re a real bass lover, and like a very V shaped signature – this might be to your liking.  But in the $350-$400 range, the Altone 350 just doesn’t scream anything but “meh”.
 

ALTONE 350 – SUMMARY

I was so hoping the Altone 350 was going to be a winner.  I loved the original Altone 200 from T-Peos.  It scored a 4.5 starts 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 and overall “package”. At the time it redefined how good a triple hybrid could be for sub $200.
 
Sadly – the Altone 350 is very much a hit and miss proposition for me. While its build is on the whole pretty good, its design has some flaws (over engineered cable, missing cinch, paintwork issues). Sonically it has a gorgeously clear mid-range, enough upper end to convey detail without getting too peaky (most of the time), but it has a flabby, over pronounce bass presence which actually detracts overall from its signature.
 
It’s almost like the designers forgot they were building a flagship – and decided they would tune it for todays bass loving younger generation.  The problem they have is that the same younger generation is unlikely to shell out close to $400 for an IEM when they can get bassier signatures for a lot cheaper.  And the people who typically will par more for a quality IEM are often not the type of consumer who want this much bass. I know I’m stereotyping here (and I shouldn’t), but the Altone 350 really strikes me as being totally confused as to its target market.
 
Sadly – I would not recommend the Altone 350 to anyone I know – unless they really love a lot of bass with a very V shaped signature. There are far better IEMs out there.
 
I struggled with how to grade these – because they aren’t “that bad” sonically, but they aren’t flagship quality either.  For me – they are a 2.5 stars at best – and I know on Head-Fi this shows as a negative – perhaps for the money being asked, this is a true reflection (on my scale anyway) of their current performance.
 
Once again though, I’d like to pass my thanks to svyr, Empj,  and T-Peos for giving me the chance to try these.
 
RECOMMENDATIONS TO T-PEOS
 
Start again from the Altone 200 – 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.