TRN STM

disclaimer:  I was approached by a representative of TRN regarding reviewing their products.  The model initially proposed is one I had already reviewed so I suggested the STM as a possible alternative.  The STM was  provided for sake of this review via their Amazon store.  I have received no compensation for this review beyond the sample itself, nor have I received any direction or instruction on whqt to include.  If you have an interest in TRN visit their facebook page or to purchase the STM visit their Amazon Store.

 

Unboxing / Packaging:

Packaging on the STM is fairly standard with the line drawing of the earpiece on the front of the slip-cover and specs on the reverse.   Removing the cover reveals the earpieces in a foam tray with a clear plastic top protecting them from above.  Hiding under the foam tray are the additional tips, cable, filters, and manual.  Three sets of silicone tips in small, medium, and large are provided but no foams are in the kit, nor is there a carrying case or cable tie provided.  The filters screw onto the nozzles and form the lip for tip retention in addition to tuning primarily the balanced armature in the nozzle.   At ~$20, I can forgive the lack of case but a cable tie would be a nice an inexpensive addition to complete the kit.

 

Build/Fit:

The STM uses a resin inner shell in either blue or dark green, and a stamped metal outer shell held on with a single star screw that sits almost directly behind the nozzle.   The star screw is tiny and utilizes a t2 driver that is smaller than what comes in most kits so specialty tools will be needed if removing the faceplates becomes necessary.   Shape is the standard inverted tear shape with nozzles exiting the bottom and connectors on the top of the front face.   Nozzles are brass and have a forward rake and a pronounced lip for tip retention.  Insertion depth is about average resulting in isolation that is also middle of the pack as it doesn’t put a lot of the body of the earphone directly over the ear canal.   I found comfort to be good with very little physical fatigue resulting from extended wear but those with small ears may want to audition before purchase as these do sit more in the ear than on it.

 

Internals:

The STM is an entry level hybrid using a 10mm dynamic driver and a single 30019 balanced armature driver.   Nominal impedance is listed at 18Ω with a sensitivity of 106 dB/mW.   These are easy to drive and work well from smartphone or tablet and while the scale at least a little bit qualitatively, I don’t feel those using them from a phone or tablet are missing out.  These were built with the casual phone user in mind and worked well paired with my LG and I-phone.

 

Cable:

The cable provided with the STM appears to be very similar to that provided with other TRN models.  It uses the 90º style 3.5mm jack in black plastic housing (with the circle T logo on top) followed by a four strand double twist pattern cable in dark brown casing.   TRN lists the material as 4-core 6N OCC copper.  The splitter is a matching black plastic Y style with no strain reliefs above or below the splitter.  Above the splitter, cables exit as twisted pairs running to pre-formed hooks and clear QDC style housings surrounding the .75mm bi-pin connector.   QDC is the hooded style with the rounded edges on the female connector as compared to the Nx7 style that uses squared connectors.    The cable is somewhat tangle prone so a cable tie or other cable management would be a nice addition to the package.

 

Sound:

 

Filters:

The STM ships with 3 sets of filters in blue, gold,  and red to help tune the sound those three are measured above and we can see that the impact of the filter is heard from about 1kHz up.  The function of the filters, per TRN is as follows:   Gold is “balanced and natural”,  Red is “deep bass, fast transient”, and Blue is “resolving treble”.     All three filters have a V shaped signature so while gold is listed as balanced, it actually is only slightly different from the other two.   Gold seems to have a bit more mids while blue and red step the mids back slightly to expose more of the top or low end.     I”m not sure how a filter is supposed to change transient speed  and think at least that portion of the definition is more marketing speak than anything practical.   For purposes of this review, I tried all three and agree that basically red = bass forward,  gold = a bit more mids and blue = treble forward  beyond that the claims of deeper, faster etc are fluff.

 

Bass:

The STM has good sub-bass presence with an emphasis centered around 80Hz before dropping back slightly as you move into the mid-bass.  Low end extension is quite good for a budget model with little noticable rolloff until reaching the 30Hz range.   Mid-bass has good slam when called upon and although still in front of the mids is not particularly exaggerated or obstructive.   Driver speed is fairly good (again considering budget) with attack a bit faster than decay and a bit of note weight gained by that decay speed.   There is some mild mid-bass bleed that adds a touch of warmth but not so much as to wash out the lower mids.   None of the filters changed my impressions of the bass as all seem to have their impact well above this range.

 

Mids:

As mentioned before, regardless of which filter you pick, the STM is a V shaped signature, but the filter can influence the depth of that V with the gold providing a bit less recess than the other two.  Lower mids are a step behind the upper regardless of filter but the blue filter with its enhanced treble does manage to make male vocals sound a bit closer to the front than the other two.   Guitar growl is acceptable but lacks a little rasp it needs to be completely believable.   Strings suffer a bit as the upper-mid push adds a bit too much energy to make them sound entirely realistic.  The same problem can be seen with female vocals as they do at times become harsh and sibilance is possible in extreme cases.    Here the red filter does the best job of taming that harshness but at the expense of stepping the mids and vocals backward into the mix.

 

Treble:

The biggest impact of the filters is felt in the upper-mids and lower-treble range where perhaps oddly, the blue has less energy than the other two.   The transition from mid to treble is cleanest on the blue filter and most exaggerated on the gold with the red falling into the middle ground.   Lower treble is emphasized in all 3 tunings before dropping back as it moves into the true treble range.   Snare rattle is quite good but cymbals lack a bit of energy due to the treble fall off.   There is an emphasis added in the 11kHz range to bring back some air and it does keep the STM from feeling closed in but sparkle is limited.

 

Soundstage / Imaging:

Stage is wider than deep with some sense of height.  I’d liken stage size to a high school auditorium so not stadium size, but not room sized either.    Seating the orchestra is fairly straight forward with no glaring misplacements and good instrument separation throughout.   Imaging is passable with movement being easy to pick out but placements being somewhat generalized rather than precise.  This seems to be especially true around center stage with positions further to the right or left being more exacting in nature.   Layering is good with compression only evident as bass complexity ramps up.

 

Thoughts / Conclusion:

Its not hard to find the faults in the STM, but with an average street price of less than $20, are any of them really fair criticism?   The STM is a budget mild V tuning in a comfortable shell that does its best work with pop, hip-hop, and other popular genres.  This is exactly the market TRN targeted and in that respect, its a good solid offering.  I wouldn’t consider it a first choice for strings, classical, or choral music, but then again no sub-$100 in ear has ever landed my recommendation for those so its hardly surprising that this one doesn’t.    The tuning offerings help some and I found myself finding different filters most likable at different times along the way so there is something here for most in that regard as well.   These make a good choice for outdoor use, giving the kids, handing out as small gifts to your audio novice friends etc.   They really are one of the better $20 spends I’ve tested.