Fir Audio e12 Review

Fir Audio e12 Review by MajorHiFi

Fir Audio has a solid lineup of premium IEMs that include the Radon 6 and Krypton 5. Their latest release is the e12, a new universal IEM to add to their current line that will set you back $1,799. With the e12, Fir Audio looks to introduce some new technology that features swappable faceplates. Is the e12 up to the standard that Fir Audio has set with this line of IEMs?

Fir Audio e12 items

What You Get

  • e12 IEMs
  • 2-pin cable with 4.4mm balanced termination
  • Circular carrying case
  • 3 sets of foam tips
  • 3 sets of silicone tips
  • Cleaning tool
  • Faceplate removal tool

Fir Audio e12 single

Look & Feel

Most of Fir Audio’s IEMs have a similar shape and use the same high-grade materials. These machine aluminum shells look and feel extremely refined and present a rigid structure. The e12 has a bit smaller of a shape this time around, which makes for an even more ergonomic shape to fit in your ears. With the e12, seal is more of a concern compared to most IEMs, since its bass response heavily relies on where the shell is placed in your ear. The provided ear tips might not get you there, so it’s important to have some variety in tips to achieve the right seal for you. Fir Audio also introduces their SwapX faceplates that allow you to physically remove the plate and easily access the internal components.

Fir Audio e12 cable


The e12 uses a 12mm electro-dynamic driver. Along with the earphone chassis that acts as a secondary transducer for bass performance. Paired together, this driver configuration is called Tactile bass which they hope will enhance the depth of the bass frequencies. Along with that, the e12 incorporates Atom venting, which helps control air pressure from inside of the ear canal.

Fir Audio e12 pair


You should expect accurate and precise imaging with the e12. The soundstage could be considered a bit linear, but the sound elements appear open enough in the mix to provide width and separation. It performs exceptional layering, but the e12 plays with the edge of feeling open. Everything is placed close to your head and doesn’t exhibit that much height or wrap around. You never feel engulfed by the soundstage, but the instruments and effects still inhabit a spacious sonic environment.

Low End

At first, it might not seem like the bass is particularly loaded with vibrating textures. There’s definitely great clarity in the lows, but the timbre of the notes can come off as a little too plain for some listeners. The e12 shows some semblance of weight in certain tracks, but the amount of impact you get still might not be what you’re after. I think the e12 has no problem communicating full bass notes, but its rumble and punch aren’t very consistent characteristics of the lows throughout the sound signature.


There’s a ton of energy in the midrange, helped by the e12’s exceptional detail retrieval and overall transparency. No part of the frequency response is close to being recessed, or veiled. You get the sense that the full spectrum of sound is being revealed to you, with instruments showcasing realism in their reproduction, and vocals coming alive with commanding grace. There’s a technical feeling to how the mids respond here, and it can come off as a bit cold, but the level of clarity is hard to not be gripped by.


With the amount of treble detail offered on the e12, the timbre is very bright. People like me who like a little brightness in highs won’t find much issue here, however, it can still come off a little too harsh due to the increased amplitude of the highs. There’s tons of sizzle and crispness to the treble and it adds a lot of flavor, but sometimes it’s not the easiest response to fully digest.


With the e12, Fir Audio provides an impressive and inventive IEM that houses an exciting sound. It’s not always the easiest to listen to sound signatures for me, but you can’t deny the level of detail that it displays. You also have to appreciate the level of craftsmanship that goes into the e12, with its removable faceplate being a unique factor in its design. This is what’s going to make the e12 stand out the most, as it occupies a pretty competitive price range. These innovations will definitely help establish a stronger foundation for future IEMs that Fir Audio can build upon.

Pros Cons
  • Precise imaging
  • Strong bass with the right fit
  • Lush mids
  • Great cable
  • Comfortable fit
  • Innovative design
  • Close soundstage¬†
  • Provided ear tips might not have the proper seal for ideal bass performance


Apply the Discount code to save: “majorhifi-save10”

The Fir Audio e12 is available at Audio46.

Compare the ranking of various headphones, earbuds and in-ear monitors using our tools.

Discuss this, and much more, over on our forum.

MAJORHIFI may receive commissions from retail offers.
Previous articleFostex TH-616 Review
Next articleOneOdio A10 Review
Alex S. is a sound designer and voice-over artist who has worked in film, commercials, and podcasts. He loves horror movies and emo music.