TRN STM

Disclaimer:

I would like to thank TRN Flagship Store for providing a review unit of the STM. Check them out on Lazada (Shop at TRN online with great deals | lazada.com.ph)! Rest assured that my impressions written in this review are my own personal thoughts and opinions and in no way influenced by outside parties.

I am not an expert in this hobby nor claim to be an audiophile. I just love listening to music and am fond of writing articles.


Introduction:

I guess we don’t need any more intro for TRN as they’re one of the more famous mainstream companies that provide good value products for the masses. The TRN STM is a 1 BA + 1 DD hybrid, selling for around ~20 USD on several sites with three tuning filters, available in either “College Blue” or “Verdant Green,” using a QDC connection. It has an impedance of 24 ohms and a sensitivity of 106 dB, making it easy to drive with virtually any device.


These were plugged to my Oppo Reno 4 with the Earstudio HUD100 MK2 (bypass mode, low power) for the review, at low-medium listening volume.



Build and Comfort: “most used shell of all time” which makes sense as it lowers the manufacturing cost and makes it more affordable. It’s not heavy and should fit most ears. Faceplate is metal and somehow reminds me of the OG Gundams. Nozzle is of course metal as well with a screw mechanism for the tuning filters that lock in place satisfyingly. Cable is literally the same as the one on the KB Ear KS1 with one major difference – the STM cable has waaay better shaped earhooks, thus being more comfortable to wear.



Package: 3 pairs of silicone tips (S/M/L). Paperwork. QC certificate. 4 core cable (w/ mic option). Free foam tips for every purchase.


Now, onto sound:

For this review, the IEM was left in stock mode, without mods other than using the KP580 stock tips as I didn’t like the feel with the STM stock tips.


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Tuning Filters:

Blue – brightest sounding filter of all. Most detailed filter but also the most fatiguing and artificial due to the treble region not being dampened, thus highlighting the flaw of the BA. Because of the elevation in the upper spectrum, bass is perceived by the ear to be less in quantity.

Gold – “generic” V-shape. It would have been good if not for the elevation of the upper midrange that makes them excessively shouty. Treble quantity is less than blue and slightly more than red. This at least gives me an idea of what “female poison” sounds like.

Red – my preferred filter. Most balanced sounding of the three. Upper midrange is at a comfortable level and treble is the least amount here but still provides enough air and presence. Non-fatiguing. Bass quantity perceived is most emphasized with this filter due to the least amount in quantity of the upper midrange and treble region. The cons of the BA, namely the thinness and artificial-ness, are most “hidden” with this filter.


General Sound Impressions:

Bass: Red > Gold >= Blue. Bass quantity doesn’t change among the filters but more so how much bass is perceived by the ear in relation to treble quantity. Slight elevation in mid-bass and extends quite well. For those looking for the “slam,” these aren’t for you. It’s nowhere near “basshead” in quantity, but in quality? Now we’re talking! The STM reproduces bass in a fast and tight fashion that shows ample texture, followed by the control that handles EDM drops with slight mid-bass bleed.

Midrange: Gold > Blue >= Red (upper midrange, specifically). Sounds thin and artificial, there’s no other way to go around it. These, however, don’t lack the bite I usually look for in a lead guitar. Due to the influence of the bass bleed, warmth shows in the midrange, but not by a lot. With the filters, only difference would be how forward the upper midrange is. I don’t recommend these to individuals that listen majorly to vocal/acoustic tracks; otherwise, it shouldn’t be a problem (e.g., techno, EDM, etc.)

Treble: Blue > Gold > Red. It’s airy but isn’t controlled, that is why splash often occurs but isn’t to the point of being unlistenable. Quantity will depend on filter used. Emphasis is on the lower treble.

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Timbre: I now understand what BA timbre is. These are distinctly more different compared to dynamic drivers. There’s a certain metallic tint/artificial-ness to sound produced which might be a problem if one listens to a lot of vocal/acoustic-heavy tracks.

Soundstage, Imaging, and Separation: Soundstage will depend on the filter with the blue being the “biggest,” but generally for any filter, soundstage isn’t congested and actually has a lot of space to move around (more width, less depth). Imaging and separation is decent and you should be able to survive with any genre (to a reasonable extent).

Detail-retrieval: Depends on the filter. With the blue one, due to “zero” dampening of the treble region, they render the most detail, in exchange for a more fatiguing listen, and the red being the least detailed but least fatiguing.

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Conclusion:

The TRN STM offers good value in a saturated price point with a ton of competition. It’s main selling point? It has tuning filters to tweak the sound according to your preference. If you want that and can live with the cons, then it will be a good buy for you.


****If you have other questions/concerns with the IEM mentioned, feel free to message me****

The STM is another budget hybrid IEM (1BA + 1DD) from TRN that includes interchangeable nozzle to suit your preferred sound signature, meaning that it is highly customizable to suit the user’s need. TRN products have been good, from my past experiences with the TRN IM1, TRN V20 and TRN M10, as the V20 is my favourite of all that I own, would this be my next favourite budget IEM in general? Let’s find out!

Thanks to IZ POP us sending me this review unit for me to review, and of course I am not paid and the review that I am presenting is a total honest opinion from me after a week of usage.

Tested on
Samsung S20+ > JCALLY TYPE C Pro DAC > XU09 Hifi Headphone Amplifier > TRN STM


Packaging
The packaging is very similar to past TRN offerings, it includes the cable, the units, tips and some papers. The tips they provided are 2 different kinds of tips, wide and narrow bores, but for my testing and my preference on which fits better, I conducted the tests in the wide bore tips.

Build Quality
It is extremely lightweight, it feels good in the hand but not great. It does not feel hollow, but a very light solid plastic is how I would describe it. The design on them is pretty nice, I do like the pattern on the face plate, it is loud but subtle at the same time which is very interesting. The cable is okay, definitely better than other brands’ similarly priced offerings. I think for some people first impression with the units would think that it is a cheap product.


But how is the sound?

Song tested:
Marie Plassard - Ivre
Angele – Tu me regardes
The Alan Parsons Project – La Sagrada Familia
Yanni – Thirst For Life
Pink Floyd – Dogs
The Temptations – Papa Was A Rollin’ Stone


Gold filter (Balanced)

Bass
The bass is definitely present and has a very nice impact overall, emphasis on the word “nice”, I would say that it is not too rumbly but with the mixture of other frequencies, it is sufficient. It does not overpower the other frequencies. Drums and bass guitars sound thick enough for my taste, which is very enjoyable. With this filter, it maybe not a basshead preference but you can definitely survive with this.

Mids
Vocals are a bit behind if you listened very very closely but not too behind that the bass covering them up. The tonality is pretty good for its price. Female voices sound pretty natural and more forward than the male voice (comparatively). Piano sounds pretty good, every keypresses can be felt Guitars riffs are also pretty sweet, is what I would describe it. I can hear the picking on the guitar pretty clearly which is always nice to listen to, as it creates a more realistic signature.

Treble
The treble has a touch sparkle, definitely not too dark sounding, and also not the most detailed sound I have heard but for the price, it sounds very much better than the asking price. Sibilant is not present throughout my testing, which contributes to a non-ear fatiguing experience. Treble-sensitive people need not to worry about this issue. Cymbal strikes don’t sound thin, which combining with the other drum sounds, it is very enjoyable


Red Filter (Low frequency emphasis)

Bass
The bass is noticeably increased from the gold filter. The rumbling effect is greatly improved too, causes the slight addition on the overall warmer tone overall. Drum kicks have better impact overall.

Mids
To my ears the positioning of the male and female vocals don’t really differ much from the gold filter, even though the bass has been increased. The mids are still presented well and forward overall.

Treble
I would say the amount of treble are almost the same but because the increase of the bass “recesses” the other frequencies slightly, but even that the details can still be heard clearly.


Blue Filter (High frequency emphasis)

Bass
The bass amount is slightly decreased than the red filter, almost similar with the gold filter when it comes to bass.

Mids
The vocals are more forward than the last two types of filters. It almost feels more in front of my face when the singer sings, which I do enjoy.

Treble
The treble definitely sounds louder but a touch thinner than the rest of the filters. More micro details can be heard. Basically, when I listen to this filter, I pay more attention on the details rather than the overall harmony because the details really stand out this one. The highs are a a little harsh for me, sometimes it results to slight sibilant and piercing but that only happen on a prone sibilant tracks in very high volume, and could make the user ear-fatigue, but in normal volume it is okay.

Overall
Soundstage
It is not intimate that’s for sure, I’d say wide enough for that 3D surround feel.

Instrument Separation & Imaging
Pretty good, as most of TRN products, I can pin point where the instruments are. Imaging is also pretty good


CONCLUSION
I think it is one of the best budget TRN product to date, even though the build quality is not the strong point. It is overall a relaxed and enjoyable sound. Would I recommend it, yes definitely! Not a lot of other choices that provides you with different tuning filters for the price, so if you want to experience that, then the TRN STM is the way to go!



Huge thanks again for IZ POP us that provided this review unit for me to review!
Links here to purchase them:
https://www.amazon.com/Earphones-Dr...hild=1&keywords=TRN+STM&qid=1603418932&sr=8-2

Build is decent for the price, typical no frills packaging and accessories, just some tips, filters and a okay quality cable The shell is average in size slightly towards the smaller side so it should be comfortable to most ears and can be recommended for sleeping without too much ear pressure.

The filters on this IEM work unlike many that don't produce a audible difference. This makes this quite the fun IEM to play around with not only tip and cable roll but in combination with the filter nozzles its very customizable.

Basic sound:

Bass is Good it has a good quality of Sub-Bass and Mid-Bass its far from bloated and thick.
Bass is north of neutral with good details and a rapid response I found it pleasant for long use without fatigue.

Mids are clear and forward with some good details although I found with the Blue filter them to be somewhat shouty at times this was easily fixed.

Treble; Was full of details as well with sparkle and not harsh with the red filters.

Soundstage is good better than average in my opinion with some very good imaging.

Conclution:
This is a solid Budget performer but the big selling point is the filters and its customizable sound overall its a good buy and its V-U shaped signature should be something most people can enjoy.



Headphones and Coffee

DISCLAIMER

I would like to thank the TRN Official Store for providing the TRN STM review unit.


EXECUTIVE SUMMARY

The TRN STM is a budget CHIFI brightish U-shaped hybrid that offers 3 tuning nozzles to finetune the sound signature. It has good price to performance ratio and good technicalities for the price. A nitpick would be the common artificial BA timbre for acoustic instruments and thinner note weight. Don’t be expecting a tour de force for the price, (and keep your expectations in check), but I think its very decent value for 20ish bucks.


SPECIFICATIONS

• Driver unit: 1DD+1BA hybrid unit
• Impedance: 24 ohms
• Earphone sensitivity: 106dB/mW
• Frequency range: 20 – 2000Hz
• Earphone interface: 2Pin
• Tested at $22 USD

ACCESSORIES

In addition to the IEM, it comes with:

1) Silicone tips (S/M/L).

2) Stock cable – generally usable sonic wise, no chin cinch, slight microphonics.

3) 3 pairs of tuning nozzles to change the sound signature



BUILD/COMFORT

Though the TRN STM looks a bit cheap in appearance, it is very light, comfortable and well built. No issues with wearing it for long sessions.

I didn’t detect any driver flex.

I’m not a fan of MMCX connectors due to potential longevity issues, and am glad the TRN STM came with a 2 pin connector.


ISOLATION

The TRN STM has slightly above average isolation, not as good as some unvented BA types, but adequate enough for outdoors usage.


DRIVABILITY

The TRN STM is very drivable from lower powered gear like smartphones, so no amping requirements necessary.


SOUND & TECHNICALITIES

The TRN STM on the default gold filter sports a bright U shaped tuning, with some boosted upper mids. The bass actually looks anemic on the graphs, but on actual listening (with a good eartip fit), they are slightly north of neutral and weightier than the graphs suggest (this is coming from a self-professed basshead), with quite good subbass extension.


TRN STM graph, courtesy of KopiOKaya of Audioreviews (IEC711 compliant coupler). 8 kHZ area is probably a resonance peak.


Some BA (balanced armature) containing CHIFI such as some KZs and the TRN VX didn’t receive the best reviews from non trebleheads for the overly harsh upper mids/treble, probably cause of an undampened BA being nestled in the nozzle, which is a common bugbear for “westernized” ears. The TRN STM still has a BA hiding in the nozzle, but the tuning filters provide some dampening effect with the materials inside their nozzles, and this is a great move from TRN, to not only let one finetune the sound signature, but also to help to dampen the upper mids/treble glare for our treble sensitive breathen.


Scarface says: “Say hello to my little friend BA in the nozzle”. Not to be a wet blanket, but luckily this BA in the nozzle can be dampened with tuning nozzles.


As per the graph below, there are 3 tuning filters which mostly affect the 2kHz – 5kHz regions (though some of the sound impressions may not correspond to the graphs, eg bass quantity and upper treble):


TRN STM graph with filters, courtesy of KopiOKaya of Audioreviews (IEC711 compliant coupler). 8 kHZ area is probably a resonance peak.



This pic is taken from the TRN store page, it purportedly describes what the various filters do to the sound. Spoiler: some of the info is misleading, not sure if this is a translation issue, or just a different (cultural perhaps?) interpretation.

• Gold filters (stock) – make the sound “balanced and natural” according to the TRN store page. I dunno how TRN is marketing the gold filters as “balanced and natural” as it sounds like a bright U shape with boosted upper mids to me actually (the red filters sound more “balanced” for me). I find the upper mids more forward with this gold filter, with perceived depressed lower mids, and the upper mids can get hot sometimes, though it isn’t as bad as some other CHIFI offenders in terms of upper mid glare (cough cough some KZs, and the recent TRN-VX big brother). The subbass is actually quite well extended, more than the graphs would imply. Treble extension with gold filters is quite good. Perhaps for the local mainland tuners, this sound is “balanced and natural” to them, but I think treble sensitive westerners may need to try the red filter as this gold filter can get fatiguing with longer sessions at the upper mids area especially.

• Blue filters – makes it have a “resolving treble” according to the TRN store page. Of the 3 descriptions of the various filters above, this sounds (no pun intended) the most legit. The bass is perceived to be decreased with the upper treble being at the forefront, with more details in the treble heard. Not my cup of tea as the excessive details can get fatiguing with longer sessions, but detailheads and trebleheads may like it. The upper mids on this tuning filter is just slightly less than the gold filters.

• Red filters – “deep bass, fast transient” according to the TRN store page. The red filters does make the upper mids glare lesser and reduces treble a tinge compared to the stock gold filters. This is my preferred tuning filter, and actually sounds the most balanced of the 3 and it makes the TRN-STM to be more vocal centric. The subbass seems to be of about the same quantity and extension as with the gold filters, not sure why the store pages say it is “deep bass”.

So the tuning filters thankfully work to change the sound signature, and ain’t gimmicks (cough cough LOOKING AT YOU NiceHCK M6), though it may not exactly correspond to the store page’s description.

Bass as discussed above is quite dependent on the filter used, but the bass is generally on the punchier side, with midbass > subbass in quantity. Bass is quite fast and has slightly above average texturing. Mids are generally boosted at the upper mids across the different filters, and the treble is also on the brighter side, with good extension and details. Those that are sensitive to the usual CHIFI saw tooth upper mids and treble will likely appreciate the red filters the most.

Technicalities are good for the price, with great imaging, details and imaging at this price bracket. Soundstage is also good, with it being wider and deeper than tall, but nevertheless, music didn’t sound too congested on this set even with complex music. I liked that transients are rather fast on this set. Cymbals are occasionally splashy but ain’t as artificial as some other budget contenders.

For a budget hybrid, the TRN STM’s tuning is quite coherent actually, even with the various filters placed on, I didn’t really hear a significant crossover point on the TRN STM.

Unfortunately, timbre is poor for acoustic instruments, especially at the frequencies handled by the BA driver, so those that listen to predominantly acoustic instruments or who are vocal lovers might need to look elsewhere. Note weight is also on the thinner side, would have preferred more meat in the bones, so to speak, but these are small issues in the big scheme of things, considering the $22 USD asking price.


CONCLUSIONS

The TRN STM is a very decent budget CHIFI brightish U shaped hybrid that offers 3 tuning nozzles to finetune the sound signature. As such, it opens different permutations for sound signature in the music and can cater to both trebleheads and treble sensitive folks. It has good price to performance ratio, especially in the area of technicalities. However, a nitpick would be the usual BA timbre for acoustic instruments found in budget hybrids, with a leaner note weight.

The $20ish CHIFI market is ultra competitive, but I think TRN STM’s tuning filters will give it an extra feather in its cap when it comes to potential sales. In fact, one can even see it as getting 3 IEMs for one purchase when getting the TRN STM, due to the 3 different tuning nozzles (which are thankfully not gimmicks), giving different sound signatures.

At this price segment, I like this set more than the recent KBEAR KS2 and CCA C10 Pro (in terms of timbre/tonality), but it still loses to the KBEAR KB04 as an overall package, other than the tuning filters. So, don’t be expecting a tour de force for the price, (and keep your expectations in check), but I think the TRN STM is still extremely decent for 20ish bucks. I’ll probably be stocking up on a few sets to give as Christmas gifts this year.

TRN STM Review

Snappy tight clean bass

Detail sharp non fatiguing highs , slight dryness, Clean mids and good vocals

Fun listen , medium energy v shape

Stock tuning nozzles are best

Excellent for price Perfect entry level iem

Good build dd and ba are well blended

Don’t need amp to sound good

Enjoyable dd for low end

Comfort fit and seal, Handles eq well

Blue nozzles decrease bass and increase highs and detail.

Red nozzles created a mid/vocal focused iem but leave sub bass alone, tame highs a tad.

Gold nozzles are my favorite.

Good separation and instrument placement in this range. Wide open sound.

Recommend