Masters of Classical Music (MoCM) – FiR Audio M4

MoCM – FiR Audio M4


The FiR Audio M4 was provided to me by FiR Audio and Project Perfection for my full review. My choice to include the M4 in this series was entirely my own and no incentive was given for doing so.

FiR Audio M4

  • Drivers: 1 x dynamic driver (low), 3 x balanced armatures (mid, high)
  • Frequency response: 10hz – 20Khz
  • Impedance: 6.4 ohms
  • Cable: DITA Audio Oslo (aftermarket)
  • Price: US$1,899 (M4) and US$599 (Oslo)


The Introduction to Masters of Classical Music could be found here.


The FiR Audio M4 were one of my biggest surprises in reviewing. Much brighter in tonality than I generally like, I was still swayed by the M4’s technical excellence and ended up absolutely loving them. It did require some fine tuning and I wrote my full review using the Cowon Plenue 2 as my source instead of the Lotoo PAW6000 because the pairing with the Lotoo was a bit too bright for me. Here once again I am switching sources, as well as the cable in order to tone down the brightness a little and I found excellent synergy between the M4, the Shanling M8 and DITA Audio Oslo.

The Shanling M8 is a recently released high-end DAP with a few key differences compared to the PAW6000. It does not have the deep black background of the PAW6000 or the note articulation, instead the M8 has a bigger stage, slightly larger note size and, very important, more transparent notes. With that last I mean that notes feel more complete, without added emphasis on a particular frequency to create note articulation. This results in a more natural and slightly smoother presentation that reproduces instruments more accurately, which is where I feel the M8 and M4 complement each other. The M4 are very accurate without much in the way of coloration, but benefit from a smoother source to tone down the brightness a bit and reveal an incredible level of textures and details. The M8 also pushes the stage of the M4 with the Oslo cable out even further than it already was to something quite exceptionally big.

In all, I felt there was great synergy between these three and the M8 had one additional key difference, it allowed me to stream Idagio natively. I have previously mentioned Idagio in the introduction to this series and because I felt it was so appropriate, decided to take their Premium+ subscription so I would have access to a huge archive of classical music in lossless format (16 bit, 44.1 kHz flac). Perhaps not as good as some of my high-resolution downloads, but the convenience here is in having access to different versions of the same piece. i.e. Every conductor will steer the performance in his or her own direction, like for example John Eliot Gardiner and his fast and revolution-inspired interpretation of Beethoven 5th symphony. Idagio gives access to some highly acclaimed interpretations and performances.


General characteristics

The presentation of the M4 is quite different from the Dream XLS in a number of ways that in themselves can actually be just what some people are looking for when listening to classical music. Consider the stage. Start by getting up from the seat where you were sitting with the Dream XLS and take a seat several rows back. Then lift the ceiling of the venue up by quite a bit until you get a stage that feels very spacious in every direction, something like a concert hall instead of the studio environment that the Dream XLS would be by comparison. This stage is big, very big and for me personally probably the biggest stage I have heard so far. Moreover, to me the M4 feel less like notes contrasting against a black background as I get with the Dream XLS and more like a true ‘out of the head’ experience where notes come at you in a very natural way. This is in no doubt due to the tubeless design and pressure release system that very effectively counter the occlusion effect, giving an open and airy feel to the presentation.

When I wrote my general review of the M4 I stated two important things I want to put particular emphasis on here; that the M4 are outstanding technical performers and that they are very accurate. While they are not as warm sounding throughout as the Dream XLS, the M4 surprised me and keep surprising me by how accurate instruments sound and how cleanly tonal nuances are conveyed. This is done in a different way from the Dream XLS and I will try to explain by going back to the pieces I used in my previous review.

With Sinfonia Concertante the presentation of the M4 immediately feels bigger, more airy and with a very clean separation of the instruments that allows the individual tonality and texture to come across incredibly clearly. However, this also separates the flow of notes from one instrument to another a little bit and in Sinfonia Concertante this becomes very noticeable when you compare to the Dream XLS. The Dream XLS have a fluidity to them and fuller sounding instruments that together bring across harmony and lay on the emotion thickly. That is somewhat lost with the M4. The solo instruments, the violin and viola, sound beautiful, but stay more inside their own space rather than harmonizing. The second movement that has this deep sense of melancholy with the Dream XLS feels less emotional with the M4 even though it is outstanding in its technical performance. It is still emotional, absolutely beautiful even, but the M4 lay the emotion on much less thickly. Like the position of the listener being a few rows back, so too do the M4 make you more of an observer than a participant of the emotions. At least, that is how I experience it and why I find the Dream XLS more engaging.

That difference is a bit less with Beethoven’s 5th Symphony because the M4 are capable of conveying a lot of energy, making them very engaging for the 5th, although again different from the Dream XLS. The M4 have a masterful bass that has wonderful physicality, texture and an uncanny ability to position itself perfectly within the soundscape. Never do bass instruments impede on others even though they have tremendous presence and that makes the opening movement of the 5th powerful and engaging. Violins sound more airy and lighter, and give more of a contrast rather than harmonizing. Again, everything separates very cleanly while maintaining coherence, making it less organic than with the Dream XLS, but equally dynamic. There is one area where the M4 clearly have something special and that is in their ability to make instruments seem as if they are moving forward in the image as the volume builds up. So not just a movement from one side to the other, but forward and backwards as well, creating a dynamic I did not feel as clearly with the Dream XLS. Where the M4 trade off a little is in not matching that sense of being swept away with the orchestra as the third movement transitions into the fourth. Here the Dream XLS create a stronger emotional pull, for me at least.

With Paganini’s Violin Concerto #4 I find the M4 are able to reproduce the strings and techniques with exceptional detail, texture and accuracy, which is in part also because of the pairing with the M8, which improved the Dream XLS in this area too compared to the PAW6000. However, I once again find that while it is technically excellent, it lacks some of the emotion that the Dream XLS impart on this piece. That is just my personal preference and does not detract from the outstanding technical ability of the M4 that is far from dry or clinical and does most certainly convey emotions well. I would say that objectively the pairing of the M4, Oslo and M8 outperforms the Dream XLS and PAW6000 here, but I still prefer the latter for pure engagement.

In short, the M4 have a bigger “concert hall” feel to them with a bit more distance to the orchestra and the emotions of the music, while offering excellent technical performance, very clean separation without hurting coherency and great tonal accuracy.

Beethoven’s 3rd Symphony
Conductor: Simon Rattle
Performers: Vienna Philharmonic Orchestra

Beethoven’s 3rd symphony was probably the first of Beethoven’s symphonies I fell in love with and the one that really attracted me to Beethoven’s work, possibly in part because of the history behind it. Beethoven composed his third symphony between 1802 and 1804, and intended to dedicate it to Napoleon Bonaparte because of Napoleon’s role in the French revolution. The symphony was eventually given the name ‘Eroica’, basically stating it was the story of a hero, but that hero was not Napoleon. The little Frenchman (okay, he wasn’t that short, but let’s not spoil the fun) felt that being the hero of the revolution and First Consul was not enough to compensate for his diminutive size and so decided to declare himself Emperor instead. Beethoven, always tactful and diplomatic flew into a rage and crossed out the dedication from his manuscript so violently that it tore the paper on which it was written, leaving a hole where the name ‘Buonaparte’ used to be.


Manuscript of Beethoven’s 3rd symphony

The performance I chose here was conducted by Simon Rattle, which is a favourite of mine. Where I loved Gardiner’s interpretation of the 5th, I prefer Rattle’s for the 3rd. The venue in this case feels larger and there is a great flow to it. Interestingly, from what I understand the venue itself influences how a conductor adjusts the pace of their performance, as it needs to be slower in a large concert hall to allow the sound to reverberate. Even so, Rattle’s interpretation of Beethoven’s 3rd has an incredible energy to it that captures something that truly feels heroic.

The opening movement is fast flowing with a lot of emphasis on violins. The speed of the M4  easily keeps up with this pace and presents all the layers extremely well separated. The violins add to the sense of speed, while the tympani adds impact and excitement and woodwinds add nuance. The balance here leans slightly towards the violins, which I like, but what impresses me most is how well the M4 are able to present bass instruments. The tympani adds impact, sounds full and textured, yet never bleeds beyond its own position. That position is exceptionally well placed, in the back with a lot of air around it. Other bass instruments such as cellos position themselves equally superb with astonishingly good separation. Violins might have a slight emphasis, but there is no mistaking those sections where the cellos come in. Placed in the back you can readily sense the heavier tones. It is amazing to hear how in the very layered sections the M4 present you with the lightness and speed of the violins behind which sits the warmth of the bass instruments, above rise the brass instruments and mixed in the nuances of the woodwinds. It all separates and yet at no point does it feel disjointed, coherency is excellent.

The second movement provides a really interesting comparison with the Dream XLS. It is a funeral march and the movement starts off slow and melancholic with solo instruments coming up and given full attention. The M4 present the solo instruments with great clarity and air around them, a bit lighter than with the Dream XLS and coming up in a very natural way, as if originating from a point far away. The Dream XLS in comparison present these instruments more forward, with a fuller sound and more contrast. With that last I mean that the Dream XLS paint the notes vividly onto a black canvas, where the M4 instead let instruments emerge out of nowhere, more like I would expect from open-back headphones. The lighter instruments still have a wonderful timbre and tonal nuances are picked up with ease.

The third movement is energetic and shows off how well the M4 are capable of rendering percussion instruments such as the tympani with authority, while having complete control over their placement. The movement ebbs and flows between the nuances of solo instruments and punchy sections with the tympani given a prominent role. Where the Dream XLS paint instruments against a black background, the M4 feel like they imbue lightness and darkness to instruments. This means that the left side might feel darker and heavier because that is where the tympani is located, while the left side feels light and airy because that is where the violins are. The violins on the left are aided by the brass section to balance the image and in the middle you get violins and woodwinds. I am not sure if that is how the orchestra was actually placed, but that is what it sounds like.

The final movement is somewhat of a disappointment for a symphony that is supposed to be heroic because it does not achieve the grandeur of the finally of (for instance) Beethoven’s 5th. It feels a little tame and underwhelming and so I will leave the 3rd symphony here and move on to one of the greatest and most prolific composers of all time, Mozart.


Wolfgang Amadeus Mozart

Mozart’s Requiem in D Minor (K.626)
Conductor: John Butt
Performers: Dunedin Consort, Joanne Lunn (soprano), Rowan Hellier (alto), Thomas Hobbs (tenor), Matthew Brook (bass)

Perhaps the ultimate child prodigy, Wolfgang Amadeus Mozart (1756 – 1791) is not quite the first member of the “27 club”, but only because he made it to 35 instead. He is without doubt one of the greatest and best known composers of all time and was so prolific that there is a special catalogue, the Köchel catalogue, to try and keep track of it all. According to this catalogue Mozart’s final work, the unfinished ‘Requiem in D minor’ is his 626th composition (K.626). Not bad for a musician who died too young. His death is the stuff of legends and conspiracy theories (of course we all know Salieri did it!), yet his early life is no less legendary.

Mozart composed his first works (K.1-5) between the ages of 5 and 8 years old and these were written down in the ‘Nannerl Notenbuch’, a notebook written for his older sister to help her learn to play the piano. Most of it was written by his father, but some by Mozart and the various pieces are still used today to teach people how to play the piano. More impressive was that Mozart composed his first symphony at the age of 8, his Symphony No. 1 in E-flat (K.16), which is actually very enjoyable. It is only around 11 minutes long and you can find performances of it on YouTube if you are curious what an 8 year old is capable of (yes, the comments section is hilarious at times when people realize Mozart’s age).

His death of course came far too early and there is much speculation about the cause. I am nowhere near well-informed enough to join in speculating, but it seems to me likely to have been some form of illness considering the state of public health and hygiene at the time. There are however some wonderful anecdotes about the Requiem and Mozart’s death, some coming from his wife Constanze. The Requiem was commissioned anonymously through a messenger, although it turned out to have been Count Franz von Walsegg, who liked to have music written by talented musicians so that he could pass these off as his own. However, while writing it Mozart started feeling more and more like he was writing the Requiem for himself. He never finished and in order to gain the full commission payment from the count, Constanze secretly asked Franz Xaver Süssmayr to complete the Requiem.

Because it was not fully finished upon Mozart’s death, there has been much speculation about how it should have sounded if Mozart had been able to finish. This means there are many different versions of the Requiem and the one I selected is a recent attempt at reconstructing the first full performance of the Mozart/Süssmayr version of 1793, as well as the version of the Requiem most likely performed at Mozart’s funeral in 1791. The latter only consists of the one part Mozart did complete, the Requiem aeternam (introit, first movement) and the Kyrie (second movement), which was finished by two unknown hands shortly after Mozart’s death. Why the Requiem? Because the M4 also do excellent vocals and I wanted to highlight those in this section.


In my full review of the M4 I was a little critical of vocals, but for choral music such as Mozart’s requiem they are actually really good. Perhaps I was too critical at first or perhaps it is simply the difference between intimate jazz, for which I like more forward vocals, and choral music that has changed my perspective a bit. In any case, for the Requiem I think voices have excellent density and clarity, with a more neutral positioning that works well to give space for the choir to be presented. Male vocals, much like bass instruments, have weight to them with good chestiness that is never dominant. This is balanced with smooth and clear female vocals, where not even the soprano exhibits sibilance, although it is by no means rolled off or attenuated and so could still have a bit of bite for the more treble sensitive among us. I find that especially at the extreme ends, for the soprano and the bass, vocals are very powerful and all vocals have a crisp and clear presentation. Compare that to the Dream XLS and I find that the DITA have softer vocals that are not as clearly defined, nor as powerful.

From what I understand this performance was aimed at getting the texture of the vocal presentation right by having the solo voices integrate with the choir in a way that feels like the soloist is projected from the choir. The M4 separate these layers just enough to convey that effect very clearly without harming the coherency. ‘Dies irae’ is one of my favourite movements because of its wild and layered nature. The M4 are able to unpick the whirlwind of voices and strings with ease without harming coherency, while the Dream XLS blend everything more together. The M4 provide a more energetic presentation that I think suits it better.

Most famous of all the movements of the Requiem is possibly ‘Lacrimosa’ for its frequent use in television series and movies (I got 75 hits in Mozart’s Internet Movie Database page -who knew he even had one?!-). In this performance it feels less dramatic than in soundtracks, but still strongly emotional and takes full advantage of the balanced and powerful vocals the M4 are able to reproduce. The M4 present it very clean and clear with a bit less emotion perhaps than the Dream XLS. There is something eery about it because of how the violins are played over which are layered vocals, a bit like sobbing over weeping. It is deep grief portrayed through music in a very crisp and clear way. The M4 give a little iciness to the violins to strengthen the weeping effect and the powerful vocal compliment that perfectly. While I like the stronger emotion of the Dream XLS, the presentation of the M4 is astonishingly good and I feel does the movement and indeed the Requiem full justice.

I have only selected small parts of the Requiem to use to highlight the vocals of the M4 and will in the next instalment of this series go more in-depth into vocals with the Vision Ears VE5. The VE5 are masterful at vocals and the M4 get quite close to that, so there will be more on this to come.


Johannes Brahms

Brahms’ Symphony #4
Conductor: Carlos Kleiber
Performers: Wiener Philharmoniker

I was planning on including a piece here from an earlier period and thought about Brahms, before realising that Brahms actually came after Beethoven. I don’t know why I thought otherwise. Did I confuse Brahms with Bach? Or am I so talented that I spotted how Brahms was in part inspired by Bach? Probably the former because my forgetfulness and confusion is legendary when it comes to names (my wife still teases me about how long it took me to remember her parents’ names).

In any case, Brahms’ Symphony #4 was included here because it is astonishingly complex and layered to the point that I never felt my gear could do it justice until I got higher-end gear. I discovered this symphony while going through the Musopen collection, a huge collection of performances made available for free download in lossless format to help promote classical music (it can be downloaded on, just search for “Musopen collection”).

Brahms’ Symphony #4 sounded fascinating and yet I could never make much sense of it, as too much of the layering just blurred into mush. So while considering the strengths of the M4, in particular their ability to separate layers so cleanly, I felt it would be an excellent piece to include here. I did switch from the Musopen recording to Idagio because I wanted to explore various interpretations. I understood there were several notable recordings by such conductors as John Eliot Gardiner (who conducted Beethoven’s 5th featured in the first review of this series), the great Herbert von Karajan and one of the most renowned recordings seemed to be the 1981 performance conducted by Carlos Kleiber. I also listened to a few others such as Simon Rattle who conducted Beethoven’s 3rd featured earlier in this review, but felt that the energy of Kleiber’s interpretation was wonderful. I also found that the punchy nature of the M4 complimented the energy of this interpretation.

The first movement immediately made it clear that the M4 are indeed exceptionally well suited to reproducing this symphony in a detailed and clean way that is surprisingly easy to digest. Because of their (relatively) more intimate and emotional character the Dream XLS still make this movement feel very chaotic and almost fatiguing because of how much is going on. The M4 separate the many layers in a beautiful way where each layer flows over the next like one waterfall after another. Perhaps a waterfall is not the best analogy because the flow is gentle like rain. I love the opening where around 40 seconds in you hear various instruments play like rain falling down, one instrument flowing into the other with light and airy violins overlapping. I can’t begin to describe the complexity that Brahms introduces here, but it is masterful and the M4 really do it justice. Best I have heard it to date.

The second movement, like so often in classical music, slows things down and here the M4’s ability to separate so cleanly is less critical. That once again comes into play in the third movement, but only after the M4 are allowed to show off their ability for producing a ton of energy. The third movement feels joyful, energetic and almost wild even though everything must have been very carefully composed. Unlike Beethoven’s emotional roller coaster, this feels like a more technical and still infinitely enjoyable burst of energy. Very complex, incredibly layered and with tons of energy, this movement once again suits the M4 like a charm. There is a burst of energy with a wonderful tympani perfectly placed giving one heck of a punch to it, sparkly bright twinkles at the top and in between everything an orchestra has to offer. Warmth from cellos, lightness and speed from violins, nuances from woodwinds, authority from brass, it is all there in the mix, one instrument responding to another in what I can only describe as music joyfully darting around the soundscape. Love it!

The contrast with the final movement is stunning, as Brahms turns to something sombre, something bleak and again, while with Beethoven it would be deeply melancholic there is something more technical about Brahms. I read one article that said this symphony should leave you intellectually battered and that is how I experience it. Less the heart strings being pulled like with Beethoven, more the mind being challenged. Not that it lacks the emotional dimension, there is just an intellectual depth on top of it that Beethoven does not have. The finale is very strong, very powerful and I think think the M4 portray it beautifully by maintaining clarity and avoiding darkening the presentation too much. Retaining the texture, power and impact of instruments such as the prominent tympani, cellos and horns, while allowing the woodwinds to come through cleanly despite the full power of the other instruments being unleashed. It is a testament to the M4’s technical excellence that they can unpick every layer with the greatest detail and yet maintain a wonderful coherency without pushing it over the top.


Concluding thoughts

The FiR Audio M4 (paired with the DITA Audio Oslo and Shanling M8) offer an exceptionally large stage that feels more like a concert hall and present music in a very natural way by effectively countering the occlusion effect. They are very clear and airy with an outstanding ability to separate layers and reveal details while maintaining coherency and accurate sounding instruments. They have energy and yet never feel over the top with anything. It is all balanced very well with a high level of technical performance.

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