Youtube video: http://youtu.be/pjsOE5aCluY
Sources: iPhone5 alone, iPhone5 with FiiO E07k using LOD, various computers using the Microstreamer and Audioengine D3 DACs/amps.
Review notes: My initial impressions of the sound of the Marshall MonitorFX are based on direct comparisons to other headphones - in particular the Shure 1540, B&O H6, B&W P7, Beyerdynamic T51p, Sennheiser HD380 Pro, KRK 8400, Thinksound On1, v-moda M80, and notes I've accumulated from many prior reviews. I describe how I relate to the MonitorFX (i.e. my personal preferences and how I use the headphone) only after covering all of the objective issues. Note that despite the seemingly extreme measures I've described below, I ended up with one of the best (if not the best) headphones I've ever heard in this price range.
Special note for this headphone: The Monitor FX treble was recessed about 10 db more than the B&O H6 or B&W P7 (my most neutral examples at this time, although the H6 has marginally less treble than the P7) out of the box, and so I needed to perform 3 "EQ" steps to bring it up to where the H6 and P7 are. This is not an ideal way to qualify a headphone for review, since even one EQ operation can potentially create an uneven playback response. The first step was to remove the "F.T.F. System" stiff pads that block high frequencies right between the drivers and the ear canals. The sound was still rather muffled compared to the other headphones I listed above, which begs the question as to why those pads would serve any need at all. The next step was to increase the treble with iTunes or iPod/iPhone "Treble Booster" EQ, which works with the i-devices alone, and also when they're connected to an external headphone DAC or amp.
That treble boost helped a lot, but the sound was still lacking highs compared to the headphones listed above, and even the most minimal hi-fi treble that I can vouch for, so as a last resort I removed the foam backing on the earpads themselves. That last step brought the upper treble (~8-10 khz) up slightly more than what I wanted, leaving the sound a little crispy on some high-pitched percussion instruments, but still not as strong as what's standard on many expensive high fidelity headphones. Comparing tone sweeps on the MonitorFX with my other headphones, the final result I got with these 3 steps was a slight recess at 2 khz and a slight emphasis at 6, 7, and 9 khz. So while my first impressions of the MonitorFX sound were quite dark and somewhat muffled due to the very recessed treble, my final judgement based on the changes I made is a pleasant listen, with a bass that's very solid with a strong impact, but no bloat or muddiness.
Summing up the above, while I play the B&O H6, B&W P7, KRK 8400, v-moda M80 and many other headphones with no EQ or other adjustments, the MonitorFX requires the changes I described to bring the sound close enough to my other headphones for at least minimal hi-fi listening. One thing users could try is to avoid removing the foam backing from the earpads (since that's a non-reversible mod) and see if the sound is satisfactory with just the other two changes I noted. The end result that I got with the MonitorFX is a somewhat dark but smooth and reasonably detailed sound, with a bass impact that compares to the best of my headphones. In other words, pretty good performance for the price, if the user is satisfied with the sound as is or is willing to make the changes I described.
Since soundstage and certain other sonic properties are dependent to a large extent on a reasonably full treble, I can't say that the MonitorFX's soundstage is anything but average under best listening conditions as described above. But then again, for nearly any good quality headphone, the soundstage will vary widely and mostly according to the recording rather than the headphone itself. The exceptions are certain designs (i.e. Sennheiser HD800) which exaggerate the soundstage using extra-large earcups and highly angled drivers, so that the sound is bounced around some before entering the ears, like speakers in a room. Isolation with the MonitorFX is very good - better than 10 db in the midrange and a lot more higher up. Leakage is very low, so if the MonitorFX were used in a very quiet office in a cubicle next to other cubicles, coworkers in adjacent cubicles would not likely hear anything unless the volume were extremely loud.
While I can't imagine a headphone with such recessed highs being used to monitor recordings that are intended to be played back on headphones like I noted above (or on high fidelity speakers), the clamping force with the MonitorFX is pretty strong and the earpads cramp my average-size ears, which is common with monitor headphones. The earpads are a soft squishy foam covered with pleather and the headband has that soft foam underneath with a leather covering on top. The MonitorFX seems to be all metal and very well made, with probably the best cable I've seen, especially for portable use. There's a 6-inch coiled segment just down from the Apple controls - about 9 inches below the earcup, and that coil is a great feature in reducing stress on the cable if it gets yanked a few times. The plug is Apple style to go along with the Apple controls on the cable, and while I didn't get a second cable with the headphone, I did try a generic cable with standard 3.5 mm miniplugs on either end which worked perfectly.
The MonitorFX cable is single-sided, but can be plugged into either earcup. The connectors and jacks seem to be brass or gold-plated, and along with a few other brass or gold-trimmed items, they add a very nice aesthetic to the matte-black headphone. The MonitorFX comes with a small black canvas bag, which I normally don't like to use with headphones, but since the canvas is very sturdy and the earcups fold up into the headband, it may not need additional protection for carrying in luggage or backpacks.
The music tracks below were listed in several prior reviews, and are a random sample selected from the 400 most recent tracks I've acquired. Since these tracks cover a wide range of genres and were selected when I was using several different headphones, there won't be a bias toward the MonitorFX headphone with this music. My suggestion is instead of reading each comment below as an absolute unto itself, you could compare these notes to those prior reviews and other reviews as they get posted, and see how the MonitorFX compares with each individual track.
Ana Victoria - Roxanne (Pop Vocal): Spacious sound, good bass tone and impact, and the vocal sounds natural. Excellent reproduction by the MonitorFX.
Ben Goldberg - Root and Branch (Jazz): Realistic you-are-there sound with great instrumental reproduction. The MonitorFX plays this very well.
Benedictines Of Mary - O Come Emmanuel (Medieval/Female Choral/Acapella): Very spacious sound and natural reverb for a large recording venue (cathedral). The MonitorFX presents the voices realistically.
Black Sabbath - Iron Man (Classic Rock): Good instrumental detail - the vocal sounds very natural. As with most classic rock tracks, there is very little or no deep bass. The MonitorFX plays this music very smoothly, and the lack of deep bass doesn't unbalance the treble.
Candy Dulfer - Lily Was Here (Jazz): Narrow soundstage, but excellent detailed instrumental tone. The MonitorFX gives this a reasonable sense of space, but in spite of being a modern recording, the net effect is only slightly better than enhanced mono.
Cantus - Danny Boy (Traditional/Male Choral/Acapella): The MonitorFX plays the voices with enough low end warmth and weight to sound very natural. In spite of my impression that the MonitorFX has a strong bass, there is no exaggeration of the low end of the male voices on this track.
Chris Isaak - Wicked Game (Pop/Rock): The MonitorFX plays this high treble energy recording with subdued brightness - the voice and instruments are detailed but not sharp or edgy.
Daft Punk - Lose Yourself to Dance (Electronic/Disco): Less than hi-fi quality recording, but the voices are very good. There's an amazing amount of bass impact, but the bass doesn't have much detail.
David Hazeltine - Fur Elise (Jazz): A very high-quality recording from HDTracks. The MonitorFX reproduces the instruments smoothly with a gentle ambiance. The wire-brush-on-cymbal harmonics are very extended but soft.
David Lynch-Lykke Li - I'm Waiting Here (Soundtrack/Vocal): Dark, moody song - Lykke's voice is very detailed, the strong bass impacts are very good, but most of the instrumentation is soft and kept in the background. The MonitorFX plays this music extremely well given the sonic limitations.
Dream Theater - Take The Time (Metal): The sound quality here is limited, but the MonitorFX is smooth enough to bring out the details in this very busy music without verging on harshness.
Genesis - Follow You Follow Me (Pop/Rock):The MonitorFX makes this old and less-than-ideal recording very enjoyable, but the soundstage is fairly narrow.
Giant Drag - Wicked Game (Pop/Rock): Annie Hardy's version of the Chris Isaak hit has a lot of energy, but the quality is limited - still the MonitorFX pulls out enough detail to be a pleasant listen.
Grieg (Beecham-Royal Philharmonic) - Peer Gynt-Solveig's Lullaby (Classical): This very old (late 1950's) stereo recording must have been made on the most expensive gear in the world, since the overall sound quality and especially Ilse Hollweg's amazing voice are as close to "being there" as I've heard with some of the better classical recordings made since the year 2000. The MonitorFX plays this perfectly.
Hubert Kah - The Picture (New Wave): This track has great bass detail and weight at the same time, which I find unusual for this type of 1980's pop music. The MonitorFX plays this music very well.
Hugo Audiophile - 15-16 (Electronic): I'm not sure what the 15-16 stands for - perhaps track numbers from a CD album. The heavy deep-bass tones that start around 33-34 seconds into the track have a strong impact with the MonitorFX. This is a great recording for evaluating whether a headphone's bass will be sufficient for most environments, since for many headphones that have a weaker bass, the deep bass gets absorbed and mostly lost when the environment contains a lot of low-frequency energy.
Korn - Another Brick In the Wall (Rock): Aggressive rock that's very satisfying for hard-rock fans. The MonitorFX plays this near perfectly, which is to say, with proper edginess and bass impact, yet without unintended sonic harshness.
Kunika Kato - Fur Alina (Vibraphone): A very unusual instrumental - the tone quality is unlike anything I've heard before. Recording close-up is part of the magic here, but the MonitorFX does the rest in reproducing the full harmonics of this amazing instrument.
Michael Buble - Nice 'n Easy (Easy Listening/Jazz): This is the only track I bought by Michael Buble, but it's a great recording and vocal performance. The sound of the backing band here is rendered extremely well by the MonitorFX, and the voice isn't pumped up for Loudness Wars thankfully.
Michael Tilson Thomas - Rhapsody In Blue (20th Century Classic): Great sound and soundstage, and terrific piano playing and tone. There are some very deep bass impacts starting around 38 seconds into the 17:24 length track, and the weight of those impacts is modest but impressive with the MonitorFX.
Muse - Madness (Rock): The bass in this track has good impact and detail with the MonitorFX, and although the voice is somewhat forward, it doesn't interfere with my appreciation of the bass line here.
Phaeleh - Afterglow (feat. Soundmouse) (Electronic/Vocal): The instrumental sounds that begin this track are played very nicely by the MonitorFX, but the voice tends to overwhelm those background sounds - until the heavy bass impacts kick in. If there is any doubt about whether the MonitorFX will play heavy impactful bass with good detail (if such sounds are really in the recording), this track is the proof. If you were to begin your MonitorFX listening with this track, you might think you were listening to a headphone that has an extremely boosted but tight and detailed bass. Simply amazing.
Richard Strauss (Mester-Pasadena) - Also Sprach Zarathustra (opening) (Classical): The granddaddy of bass is in the opening 1:50 of this recording, and I've heard it only once on a large and expensive loudspeaker system in Cleveland. For most people, that experience would be indistinguishable from being in a fairly strong earthquake. The MonitorFX conveys as much of that experience as is possible on a headphone. The tympani also have good impact here.
Sargis Aslamazian - The Sky is Cloudy (Classical/Armenian): The National Chamber Orchestra of Armenia has a great classical program, and the MonitorFX plays this music with good separation, tone, and big-orchestra precision.
Satri-Tomoko Sonoda - All The Things You Are (Jazz): This track came from Bakoon Products, who make high-quality audio amplifiers. There's a lot of upright bass plucking in this track and the MonitorFX plays it pretty well, although it's recorded fairly close-up and sounds boomy at times.
Tommy Smith - Johnny Come Lately (Jazz): Small-combo jazz - sax, piano and drums. The sound is fairly close-up but well-recorded, and sounds very good with the MonitorFX, although the wire-brush-on-cymbal harmonics are not as extended as on the David Hazeltine track above.