FiR Audio M4 Review

FiR Audio M4

Build Quality and Ergonomics:

 

[responsivevoice_button]

 

The M4 has a dual color scheme, with a black body and champagne gold top. On the face plate you can see the FiR Audio logo on the left piece and the model name ‘M4’ on the right. The monitors are very well made in my opinion. The face plate and shell are perfectly closed, where there only is a small gap between them. Near the MMCX socket you can see two holes. One is for the Atom module and the other for pressure relief of the dynamic driver. The shells overall are not huge, but not exactly small either. Compared to my 64 Audio universals, the M4 is slimmer and this might result in a better fit for more people.

The MMCX sockets are protruded, so after-market cables probably won’t cover up the whole socket like FiR’s cable does. The nozzle is angled and has two lips on it. This secures the ear-tip on the nozzle and makes sure they don’t stay in your ears.

I was a bit surprised when I learned that FiR hasn’t kept on to their RCX sockets for the universal IEMs. They clearly say that their RCX sockets are more robust than any other current connector. I know they wanted to please the audiophiles who want to cable-roll on their monitors, but why didn’t they go with 2-pin? I never had a 2-pin fail on me once, whereas I broke at least two MMCX sockets in the past.

In terms of ergonomics and fit I think, that the M4 does a very good job. They fit my ears very well with deep insertion. The only discomfort they brought to me, were when I used the foam tips. They irritated my ears quite a bit and made me change to silicone after day one.

As with every universal IEM it is very important that you can get a good seal with the M4. Try different tip sizes to achieve a full seal. Otherwise you’ll end up having a sound that’s not where the M4 can take you.

FiR Audio M4

FiR Audio M4

Sound:

The M4 is touted as a warm and musical sounding IEM on FiR’s website. Something to enjoy and connect with. I’ve been following FiR’s progress for a while and have read mixed reports from people all around the globe. I was very curious to learn more about FiR’s lineup, and when I was offered the M4 for review, I couldn’t pass up the opportunity.

The following segment is based on long term listening sessions with the Lotoo PAW Gold Touch, PAW 6000 as well as the Cowon Plenue L, Chord Electronics Hugo2 and Mojo. I also took out the Broadway S amplifier by XI Audio to check how it plays with desktop equipment.

FiR’s M4 has an overall lush and rich signature, that sports good levels of warmth and a balanced to U shaped signature. The M4 has impressive bass impact, layering and a romantic and organic mid-range. Treble on the M4 has good articulation, but doesn’t produce any fatigue to my ears.

The M4 delivers an impactful bass, that oozes of texture and body. It goes deep into sub-bass with good drive and authority. It’s fast, detailed and energetic. The M4’s lows are lush and natural, where lower pitched instruments sound realistic and life-like. There however is a clear focus towards sub-bass. With Electronica you get very good punch and speed.

Let’s look at LFO’s Freak for a second. It’s a track that starts off quite calm, but results in a hectic mess that sucker punches your eardrums like Muhammad Ali. The M4 stays on top of the extremely fast lows and brings them out with control and strength.

FiR Audio M4

FiR Audio M4

Lower mid-range is tilted towards a warmer and more physical sound. Where vocals and instruments get a full bodied presentation with good density. They are presented with meat on their bones and a rich sound. Deep male singers like Leonard Cohen or Barry White have a sound that’s very full and bold. Their vocals come out as meaty and organic.

The center mid-range again sports a certain level of warmth. It’s more tilted towards neutral than the lower mids, but there still is a warm sound in them. There is good resolution, texture and layering in the mids. Throughout the entire mid-range the richness is very nice. But especially the upper mids do it for me. There is an undeniable rich glow in the upper mids, that makes them just gorgeous. Instruments have a natural presentation with good body, density and texture. They don’t sound congested or too full, which is something I am always very critical about. There’s a point where it just doesn’t sound realistic anymore. The M4 doesn’t surpass this one thankfully.

Treble on the M4 leaves me with a somewhat split opinion. On one hand it has superb extension and energy, on the other hand it can come close to sibilance. Especially s-sounds can become rather sharp and direct. A song to check it for yourself here would be the live version of Moderat’s Ghostmother. Here Sasha Ring’s voice can come to the edge of sibilance to my ears. The M4 still has very good energy and sparkle in its highs. It provides very good levels of air as well.

The M4 is suited for a wide range of genres with its lush and enjoyable signature. It has great resolution and texture across the entire frequency response. Its stereo separation is just perfect, where the scene aligns centered in front of you.

Scalability:

Some of you might have noticed, that I didn’t say anything about sound stage perception or imaging in the Sound section. This is because I think these values heavily depend on the pairing of the M4. The FiR isn’t a hard to drive monitor and it can get plenty loud with my smartphone too. But it scales just enormously with higher end gear. Unfortunately even the Lotoo PAW Gold Touch doesn’t get the M4 to its peak for me.

During my weeks of testing out the M4, I found that the source its paired with has a massive role in its sound reproduction. Products like the Chord Hugo2 really start to get the best out of it. With the British FPGA loaded DAC/Amp you get an open presentation as you would expect from a tube-less IEM like the M4. With DAPs and lesser powered gear it sounds more concentrated and closed in.

FiR Audio M4

FiR Audio M4

Hook the M4 up to something even more desktop sized like the Broadway S or FA-10 amplifier and you’ll immediately notice that the scalability in the M4 is big. Very big. Those amps unleash the absolute potential of the M4 and once you heard how wide and deep the FiR can spread sound stage wise, you can’t go back to unknowing. I have seen people online say, that the M4 sounds like any other IEM in that regard, and I think these people should definitely try the FiR with something higher up than just their DAP.

The Hugo2 starts to give the M4 more air around the instruments, it gives the M4 a darker background and better contrasted instruments. Imaging is absolutely perfect and so is the stage construction as a whole. With gear that doesn’t get the M4 there, it sounds more compact and packed.

One thing I have to still note though. The M4 does pick up hissing from the Broadway S amplifier (also in pure battery mode). It does go away if you turn up the volume, but as someone who likes to listen at lower volumes it didn’t vanish for me.

Need comparisons to other high end IEMs? You’ll find just that on page three!

4.7/5 - (27 votes)
Facebooktwitterredditpinterestlinkedin

A daytime code monkey with a passion for audio and his kids, Linus tends to look at gear with a technical approach, trying to understand why certain things sound the way they do. When there is no music around, Linus goes the extra mile and annoys the hell out of his colleagues with low level beatboxing.

2 Comments

  • Reply July 18, 2020

    PC

    Thanks for reviews

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.