Have done some preliminary a/b-ing between the Mikros 90 and the M500.
Although the M500 are admittedly fine headphones, I prefer the Mikros 90 on several fronts.
(i) Sonically, it has most to do with the Mikros 90's superior high frequency extension/resolution--the department where the MLs summarily distance themselves from the M500 and better suit my individual listening tastes/genres
(ii) Practically, it has to do with the KEFs' unconventional cable input design (with an inaccessibly recessed 2.5 mm jack), which does not allow me to use the Pipeline ET-4 cable.
(iii) Financially, the M500 cost three-to-five times the current selling price(s) of the Mikros 90.
The KEFs have very good bass, but with more midbass emphasis than the MLs. The MLs have deeper bass extension and cleaner/finer deep bass pitch definition than the KEFs.
The KEFs have a sleek, smooth, liquid and alluring midrange that is fairly well integrated with the treble and bass. By far, their midrange is the M500's strongest suit (and I confess to having often experienced its well-nigh mezmerizing effects). In this department, I can understand the popular appeal for the KEFs on the Head-Fi forum(s) and elsewhere. The MLs have a more open, clear, coherent midrange with excellent tonal differentiation and superior dynamic texturing/contrast. The MLs concede a bit of warmth, density and elasticity to the KEFs in the midrange--male vocals sound more settled and have a more "yellow-orange glow" to them over the M500, although the KEFs' upper midrange/lower treble can sound a bit smeared and disjointed on some tracks compared with the MLs. Overall, I find the Mikros 90 more resolving, nuanced and "vivacious" in the midrange than the M500. The KEF's midrange is exceptional, but ultimately loses its upper connectivity with the treble, evidenced by glare, and also loses its lower connectivity with the bass, evidenced by a looseness or boominess.
The KEFs high frequency reproduction is too reticient for my individual taste. It is "there", but sparely, lacking the ultimate reach/presence of the MLs. The M500 can sound comparatively blunted or subdued at the high frequency extremes; cymbal strikes, for example, seem neither to adequately bloom nor to adequately linger in space. A similar analogy goes for the low frequency extremes as well, where the M500 lack the bass reach and firm deep bass grasp of the Mikros 90. For me, the KEF's tandem lack of frequency extension (i.e. in either direction, treble/bass) translates into their noticably less airy, less open, less transparent, less 3-dimensional and overall less involving presentation. This is where, for my ears, the Mikros 90 most significantly outperform the M500 in apparently transcending the source material, and in much better suiting my individual listening preferences.
The Mikros 90, in my ears, resolve large-scale orchestral works, sort out complex arrangements, delineate massed voices or instruments, etc. much better than do the M500. Furthermore, the largesse of the Mikros 90's soundstage can be startling in its proportions. The M500, being warmer and mid-centric, can sound sometimes congested/bulbous by comparison. The Mikros 90, in my esteem, offer superior resolution of detail but without ever losing their sonic poise or their vital touch with the musical pulse/substrate of a recording. To me, the MLs--be it the backroom acoustics of a Muddy Waters session or the Wagnerian ethos of a no-holds-barred Ring orchestral piece--simply sound more fresh, vibrant and consistently musical--full of pleasant surprises.
My predilection for the HifiMAN HE-5LE over the HE-500, and for the Beyerdynamic DT880/2003 over the DT880/2005, fall along similar lines as my preference for the Martin Logan Mikros 90 over the KEF M500: favoring listeners who, like me, prefer the further frequency reaches to a more midrange-specific presentation. I also think that HE-500 and LCD-2 devotees will likely prefer the M500; while HE-5LE and HE-6 aficionados will likely prefer the Mikros 90. I am firmly in the camp of the latter.
I auditioned the Mikros 90 with AudioQuest's Pipeline ET-4 cable, the M500 with their stock (flat) cable. Due to the KEFs' design, and inasmuch as I would have liked to, I could not connect the M500 with the ET-4. That just might have been the M500's "undoing". For me, though, this review is about the sound and associated configuration of the gear that I will opt to live with--and will have to live with--in the long term. That said. So be it. Apparent inequity dissolved in my mind.
Associated equipment for this review:
RAM-modded Samsung DVD-HD841/Sony BDP-S580
Dakiom R203 feedback stabilizer (at RCA outputs from the disc player)
EVS IC-95 interconnect/Millersound digital cable
MAC power cords
KMF Audio headphone amplifier/Denon AVR-1905 (headphone out)
Dakiom F-273 feedback stabilizer and EVS Ground Enhancer (at headphone out)
SID disc mat
The Dave Grusin Collection (GRP)
The Beatles: Past Masters Volume 2 (Apple)
The Krueger Brothers: UP18North (Double Time)
Hank Williams Junior: Greatest Hits (RCA)
Fleetwood Mac: Behind the Mask (Warner Bros.)
Best of Eddie Arnold (RCA)
History: America's Greatest Hits (Warner Bros.)
Sir Edward Elgar: Overture Cockaigne (from Spirit of England/Nimbus)
Frederick Delius: Summer Evening (from Spirit of England/Nimbus)
Moments to Remember: Golden Hits of the 50's and 60's (Shout)
The Beach Boys: The Greatest Hits Volume 1 Good Vibrations (Capitol)
Brahms/Pogorelich: Intermezzi op. 117 (Deutsche Grammaphon)
4 Non Blondes: Bigger, Better, Faster, More (Interscope)
Neil Diamond: Heartlight (Columbia)
Annie Laurie, Songs of the British Isles (The King's Singers)
Al Martino: Great Gentlemen of Song series (Capitol)
Edited by pataburd - 1/8/14 at 9:58am