TLDR: Highly resolving, natural-sounding IEM, adding up to more than the sum of its parts.

The TRN BA8 is an all-balanced armature IEM, with 8 drivers per channel. Their configuration is as follows:

Treble 3 x 30095
Mids 2 x 29689, 2 x 50060
Bass 1 x 22955

TRN has made a big jump with the BA8 over last year’s BA5, and not just in terms of price. Improvements in tonal accuracy, resolution, and imaging make the BA8 a far clearer window into my music. Graphs notwithstanding, tuning comes across as only modestly brighter than neutral. For me, attention is drawn not to any tuning quirks but rather to a sense of clarity that feels honestly earned. Sometimes, it almost feels as though I can step on stage with the musicians. Subtle acoustic effects can be perceived – reflected sound from a floor or a wall near a musician, woodwinds that actually sound woody, rough frictional colors in the string bassists’ bowing – that present fascinating little surprises.

Comparisons
I recently acquired the NF Audio NM2, which is a really wonderful dynamic driver IEM. I thought it might provide a useful point of comparison for this review. I also compared the BA8 with the its older and lesser brother, the BA5. I took the time to carefully compare the NM2 and the BA8 but not so much the BA5 because it was quite evident that the BA5 is a bit out of its depth in this comparison.

My original intention was to use the same TRN tips on all these sets, along with the original cables for each, to simplify the comparison. However, the NM2 sounds much better to me with Starlines, so I used those tips instead. I used the Tempotec Sonata Pro HD throughout.

Priming makes a difference in perception. Moving from the NM2 to the BA8, the BA8 generally sounds a bit thin, with an unmistakable if inoffensive balanced armature character. But switching back to the NM2, the NM2 sounds euphonic and enhanced, as if a reverb or a Dolby effect is turned on. It sounds too bassy for me, too, but I’m sure many others will prefer this approach. My brain quickly adjusts to the BA character of the BA8, but there is just less to listen to on the NM2 and there’s no compensating for that.

For me, the choice between these two amounts to choosing the one that polishes the rough edges versus the one that lets you feel like you’re on stage. The NM2 feels more open. Isolation is limited. The BA8 feels more sealed and isolating in contrast, and I much prefer that. The NM2 sounds generally warmer and smoother in mids and lows but a bit of shoutiness in the upper mids and treble can arise. I prefer the BA bass of the BA8; it just seems more controlled and textured, and it’s in a more neutral balance. On the NM2 I don’t perceive the subtle differences in recording quality or the physical space of the recording session like I can with the BA8. I don’t feel like I can enter the space of the recording in the same way. The more layered and complex the music is, the more the BA8 distinguishes itself. In similar passages, the NM2 can sound compressed.

Turning to the BA5, it has treble and bass that come across as out of proportion because the mids are recessed. I tend to fidget with the volume as I try to bring the mids forward, but the highs and the lows hit me hard and I have to back off. Lots of information revealed by the BA8 is missing here, so the BA5 sounds relatively down-market, as it should, given the difference in price.

A comparison between two IEMs runs the risk of overplaying the contrast, which would give the wrong impression. As you can tell, I prefer the BA8, but I think the NM2 is also quite excellent and I’ll keep using it. Just to touch on some other comparisons, I briefly had a 4-Knowles BA/channel set that I remember as warmer and smoother than the BA8, but at the price of softer resolution. I tried the CVJ CSN, but the colorless and aggressive treble and the paucity of bass was not enjoyable. The UrbanFun YBF-ISS014 was very capable but its bass-heavy tuning just didn’t work for my music.

Preparing for this review, I took notes as I compared the BA8, the NM2, and the BA5. I include them below for those who are interested.

All in all, the BA8 justifies its price with a mature tuning and confident technicalities.

Notes
Bernstein, On the Town: Lonely Town, Pas de Deux (Tilson Thomas, London Symphony)
BA8: 1:46 climax has a lot of treble energy but doesn’t cross the line, and no congestion
NM2: warmer bass due to emphasis, climax seems compressed, violins are slightly glassy
BA5: violins lack color, all fine but a bit soft and distant

Strauss, Elektra: Ich habe keine guten Nächte (Bychkov, WDR Symphony Orchestra Cologne)
BA8: 0:18 harp and bass pizzicato in balance but distinct; 3:00 unison passage (low clarinets, Wagner tubas(?), bass) the players blend well but they can be heard separately anyway, soprano’s articulation so clear, so much to hear; loud passages at end are a bit too bright
NM2: soprano has a slightly harsh tinge sometimes (4:00), other times more rich and smooth; some shoutiness in loud passages; generally a flatter soundstage
BA5: soprano sounds good if a bit veiled; all fine but a somewhat boring

Prokofiev, Piano Concerto No. 5: II: Moderato ben accentuato (Toradze, Gergiev)
BA8: piano sounds quite clear; 1:35 high scale passages in the piano sound even and super clear, fascinating sonic effect where the piano is very close and the woodwinds are positioned center and farther back, and those woodwinds are distinct within that space (NM2 can’t do this as well); 3:41 snare is very clear
NM2: 0:50 bass line too blended (piano + string bass); 1:35 piano is at once more shouty and less clear; 2:27-2:40 basses are too thick and dull
BA5: Right from the start, the piano’s attacks sound different depending on range, clear in the high range, softer in the mid and low; 1:10 cellos have a real cheap BA quality; 1:35 fine but a bit hazy in the piano; nothing bothersome

Hindemith, Symphonic Metamorphosis: IV: Marsch (Atlanta Symphony, Levi)
BA8: 3:18 amazing imaging effect from combination of violin and bass pizzicatos, snare drum and trombones stage reflections, and timpani crescendos (not an artificial effect); 3:33, 3:54 cymbal crashes are not punishing; imaging and layering effects are astonishing at times (1:57, 2:28, 3:18) and put this IEM on another level for me.
NM2: 1:24 exaggerated bass drum sounds ridiculous (it’s partly a fault of the recording itself); 3:10 snare not so clear; 3:20: low string pizzicato, bass drum, timpani create a very cool imaging effect within the lower frequencies; 3:34 generally thick and soupy; NM2 mostly falls behind on this track.
BA5: 1:24 bass drum is wooly, too much; 1:50 horns and woodwinds sound very far away; 3:38 lots of congestion and softness but nothing offensive

Sibelius, Symphony No. 2: III. Vivacissimo (Nelsons, Boston Symphony)
BA8: generally outstanding separation and imaging; violins a bit thin at the start; 3:23 rosin-y friction in bass bowing very distinct and natural; 3:54 mallet strike in timpani is clear and separate from its decaying tone, crescendo to end remains very well-sorted, I’m still hearing individual sections (i.e. trombones, etc.) and hearing their separate micing.
NM2: good body to the sounds of all the strings; 5:10 cello unison has a lovely tone quality; 5:32 bass lacks definition compared to BA8
BA5: violins sound a bit artificial, all nice-sounding but woodwinds are a bit far and soft, I keep raising the volume to hear them and I keep having to pull back when the basses, timpani become too loud