Comparison.

This comparison was done between universal demo of M5 CIEM, using stock foam eartips and stock balanced cable, and the selection of various other hybrids, volume matched in every comparison using LPGT as my source.  Just like in sound analysis, I had to completely rewrite this section to reflect the new M5 tuning.

FIR Audio M5 vs 64 Audio Tia Fourte Noir – both have a very similar soundstage width and depth.  I also find similarities in mid-bass punch, but Noir sub-bass goes deeper with a little more rumble which elevates the perception of bass quantity.  When it comes to mids, M5 lower mids are more neutral and upper mids have more clarity and transparency, while Noir mids have more body and a little thicker in tonality, giving them warmer coloring.  Treble is similar, perhaps with Noir having a bit more crunch here.  Both IEMs were tested using the same foam marshmallow tips, and their stock SPC cables which have a lot of resemblance from outside look.

FIR Audio M5 vs 64 Audio Trio – while soundstage width here is the same, the soundstage depth of M5 is more out of your head, expanding further to give sound more holographic depth.  Bass is very similar, nearly identical, though I do feel M5 has a little more control of decay speed.  With new tuning, M5 now has a very similar more neutral lower mids and transparent detailed upper mids.  M5 treble now has more crunch, but Trio still has a touch more sparkle.

FIR Audio M5 vs 64 Audio N8 – both soundstage width and depth are similar and sounds more holographic.  With bass, N8 still packs a stronger mid-bass punch and deeper sub-bass quantity, but the quality is similar to M5.  After the re-tuning update, M5 lower mids are a little more neutral now, while both have a similar forward presentation of transparent upper mids with good retrieval of details.  Treble is nearly identical in both, though M5 sounds just a touch more natural.

FIR Audio M5 vs Campfire Audio Solaris – soundstage in both width and depth are spot on, very similar between these two IEMs.  When it comes to bass, Solaris is still faster with a shorter attack, but now both have a similar decay, making the lower end tighter and more articulate, though I still think M5 bass sounds a little more typical of dynamic driver analog performance, while Solaris leaning a little more toward faster BA performance speed.  Lower mids in both are similarly neutral, perhaps with Solaris being even a touch south of neutral, leaner.  Both have a more forward detailed upper mids, but Solar upper mids are brighter and even more revealing in tonality.  The gap in treble still remains, even so M5 now has more sparkle, Solaris treble is still brighter and crisper, and has more airiness, while M5 is more natural and less fatigue during extended listening.

FIR Audio M5 vs Empire Ears Legend X – soundstage between these two has a very similar width and depth, perhaps with LX being just a touch wider.  As expected, the lower end is more elevated in LX which is a bit overwhelming in slam for my personal taste.  Lower mids are little more neutral in M5, while LX has a fuller body.  Upper mids now match very close, being natural and detailed.  Treble also has a lot of similarities, being well-defined and under control, though LX still has a more pronounced 12k peak which gives the sound a little more airiness.

FIR Audio M5 vs Ultimate Ears UE Live – soundstage between these two is very similar, wide and deep which feels more holographic.  The bass has a similar sub-bass rumble and mid-bass punch, but I’m hearing Live bass being a little more hollow in comparison to M5.  Both have a very similar neutral lower mids, while upper mids in Live are a little more lush and smoother and M5 upper mids are more transparent and with a better retrieval of details.  Treble is where I still hear a big difference with Live’s 8k peak ruining the natural treble tonality and making the sound more sibilant.  M5 treble is more natural and a lot less fatigue in comparison.

Pair up.

M5 is very efficient and easy to drive from any portable source I tried it with.  This section of the review was also updated to reflect new IEM tuning.

Lotoo PAW Gold Touch – wide holographic soundstage expansion; balanced sound signature with a natural detailed tonality; nice punchy bass with a deep sub-bass rumble; more neutral lower mids, natural detailed upper mids with a slightly more forward presentation; well defined non-fatigue treble with a nice level of crunch and moderate airiness.

A&K SP1000 SS – wide soundstage with a slightly intimate depth; a balanced sound signature with a natural detailed tonality; bass has a little more punch and a little more sub-bass rumble (in comparison to LPGT); mids are clear and detailed, very nicely balanced, well defined non-fatigue treble.

Sony WM1Z – wide and deep, nearly holographic soundstage expansion; very nicely balanced sound signature with a natural detail more revealing tonality; bass has a strong punch, with a deeper sub-bass rumble, sounds more analog; mids have a more neutral body, natural tonality, and I also hear improved retrieval of details; treble has good definition, sounds detailed and non-fatigue here.  Excellent pair up.

Hiby R6 – wide soundstage expansion with a little more intimate depth; the signature is nicely balanced with a slightly warmer tonality; bass hits harder and goes deeper here, bass is more elevated in comparison to other DAPs; mids have a little fuller body while upper mids are smoother and more natural, with a little more forward presentation.  Treble is well defined and non-fatigue with a nice level of crunch and airiness.  I was actually surprised with this pair up since bass was elevated.

Shanling M0 – wide soundstage expansion with nice holographic depth, but the width itself is a little less in comparison to other pair ups; the sound signature is balanced, the tonality is natural and slightly more revealing; bass has a nice punch and a very good sub-bass rumble; mids have a natural slightly revealing tonality, good level of transparency, and slightly more forward presentation; treble is well defined, non-fatigue, with a little extra airiness.  Surprisingly good pair up.

Samsung Galaxy S9 – soundstage is expanded but has more depth than width; sound signature is nicely balanced with a smoother more natural tonality; bass has a nice deep sub-bass extension and stronger mid-bass punch; lower mids have a little more body, upper mids are natural, detailed; treble is well defined, non-fatigue, and with a touch more sparkle.

Conclusion.

After testing universal version of M5, I found it to be a very impressive debut for a newcomer.  But in reality, Bogdan and his crew been around the block and have over 10 years of experience in this field.  Among 4 new FIR Audio models with different hybrid driver configurations, my focus was on M5 flagship, and it certainly packs a lot of goodies.  Perhaps a hybrid design with DD low, BA mids/highs, and ES treble is no longer a groundbreaking combination since a number of other manufacturers using the same Sonion dual ESTAT treble driver with a built-in transformer.  But here we have a single ES tweeter, fully tubeless CIEM design, and a controlled leak valve.  Also, RCX connector is a unique addition, though I have a feeling it will be appreciated more by performing musicians rather than cable-rolling audiophiles.

Originally, I was planning to have just a short “first listen” impression when I got pre-production M5 pair before the official launch.  When I started listening, it expanded into a full review which I now updated to reflect the final production tuning.  It caught my attention not only based on what’s under the hood, but also because I enjoyed its coherent tuning and natural fatigue free resolving tonality.  I’m also very pleased that FIR Audio listened to all the feedback from their customers and other reviewers and updated the final tuning to reflect these suggestions.  The original M5 I tested had already a mature tuning which I enjoyed.  The final update brings mids/vocals more forward while changing the signature from v-shaped to more balanced, something that will be greatly appreciated by both musicians and audiophiles!