And here's the followup comparison to my desktop rig that I reference:
I can't comment on the M-100 since I haven't heard it, but will comment on what I've compared these with. What I am (was) after is a pair of headphones that sound good, can be driven from an iPod and have a sealed design. I don't need noise cancellation, I just want to be able to wear these in the office without everyone hearing what I'm listening to.
So based on those criteria I tried out a whole bunch of smaller on ear headphones (I'll spare you all those details) and then when comfort became an issue I decided to try out some over the ear designs. At the end of the day, I ended up with 4 headphones that I was deciding between: Sennheiser HD25-II, V-Moda M80, Polk UltraSonic 8000 and the PSB M4U. Note that I've listened to many other cans including the AKG K550, Focal Spirit, Shure, Audio Technica M50 and didn't really like the overall sound of any of them, they each had strengths but the overall sound didn't work for me.
In terms of overall sound, I'd rate the PSB close to neutral, the Polk and V-Moda as more laid back and the HD25 as brighter. Really, the HD25 is out because at times it's just to shrill, and I'll very likely be sending that one back to Amazon. It has a good shape to the sound overall, but the highs can just be a bit much at times.
So that leaves just the 3. IMO the V-Moda is fairly easily outclassed by the other two. It's probably not really a fair comparison since the V-Moda is so much smaller and more portable and sits on the ear. Honestly, before I bought the other two I was pretty satisfied with the V-Moda, but sitting on the ears wasn't comfortable and it just won't work in longer durations for me. The V-Moda lacks a bit of sparkle on the top end, but is overall pleasing.
I would actually characterize the Polk as having a similar sound but just bigger and more immersive since it's over the ear. The Polk may be slightly more refined, but has the same overall laid back sound of the V-Moda. The Polk also has a lot more bass than the V-Moda, and not sloppy bass either, it's very well controlled and still has low extension. It's not bloated, but on some types of music can actually be a bit much. The deal breaker for me though was the active noise canceling only restriction. I don't mind carrying spare batteries around with me, but actually don't like noise canceling and so needing it on all the time doesn't work for me.
So the search continued...enter the PSB M4U. These are truly a superb sounding headphone, the best of the bunch. These have a very natural sound to me. I've seen the FR curve on these and it's flat, and that's how accurate they sound. I say they're neutral, but in reality if there were a definitive line for neutral, these would probably be just to the right on the bright sound of that. They're not bright at all, but their presentation is more forward than the other cans I've heard. I've found that I actually prefer this with every type of music, so it works for me. I don't want to give the impression that these are bright because they're not, they just bring you a little closer to the stage. They're more detailed than the other cans as well, more resolving I guess you'd say, they have that sparkle that is missing in the Polks and V-Moda but without the glare of the HD25.
Their overall sound signature is perfect for me, it just fits my liking. They're not perfect cans of course, but they sound great.
I'm going to sit down tonight and do some comparisons with my desktop setup. I expect them to be easily outclassed by that setup (they better be, or I spent all that money for thing), but want to see how they hold up nonetheless.
I finally had some time to sit down and compare these with m desktop setup, and the results are shocking.
Let me start by saying that out of my desktop cans (Senn HD600, HD700, HD800, Beyer DT880) the oldest and cheapest HD600 are actually my favorite. They're not 'the best' of the bunch, that award would probably go to the HD800, but they're my favorite. They're not as refined as the other cans (except maybe the 650) but I really like their general disposition, very smooth yet engaging and with enough of the detail to suit me. The Beyers have a much better soundstage and the other 700 and 800 both have better clarity while the 650 has better bass, but none of those cans SOUND as good to me. I would like an upgrade to the 600 someday - really all I want is the overall sound signature of the 600 with the soundstage of the Beyer, that would be my ultimate headphone.
I say all that not because I think the PSB are it (because they're not), but rather to provide an overall idea of what I'm looking for and put the below into some context. And since the 600 are my favorite of the bunch, that's what I compared the PSB directly to. The PSB, like the 600, have an overall sound that I find very pleasing, yet they don't sound like the 600. Here are some impressions from my notes:
First, the 600s were tested on my main headphone rig (Mac running Amarra Hifi > Peachtree Dac-IT > Schiit Valhalla > HD600), I consider this setup (while not super high end) to be a fairly respectable system. The PSB were run in Active mode (meaning I used the built in amp) straight off a 7th ten iPod classic (that's it, no LOD or DAC, just straight off the iPod because that's why I purchased these). So the setups aren't exactly a fair comparison, but that's how each can is to be used so that how I did the comparison. Lossless files were used on both setups.
The Senns have adequate bass, actually I'd say they have very good bass and I've never felt it lacking. The PSB, however, kicks it up another notch. And I don't just mean that they have more bass (although they do), I mean that the overall bass response is more pleasing on the PSB. I don't find it boomy or bloated, these are not a 'bass' can ala the Beats or even the Polk UltraFocus 800, it's just a very natural sounding bas response. One of my favorite tests is about 3 minutes into the track Why So Serious from TDK score, and these passed even that with flying colors. The PSB are the best headphones I've ever heard at reproducing bass faithfully.
Mids and Highs
I don't know if there is a FR curve for these posted somewhere online, but if there is I'd guess it's relatively flat (with maybe a small hump in the bass to create what Barton calls the 'room feel'). These just sound very smooth and still accurate and detailed enough in the miss and highs. it's hard for me to describe the sound as anything other than damn near perfect. These headphones are not going to be the final word on detail, but they're not far off. I get more detail out of the 600, but not ALOT. One thing the 600 does well is make lesser recordings tolerable to listen to, since they're not the final word in clarity either they ten to smooth over some of the edges on bad recordings, and this is one of the reasons I like them so much. The PSB are even better at that. Muse is actually listenable on the PSB nd on the 600 it's borderline tolerable depending on which album. I
The PSB are a closed design, but they sound bigger and less 'in your head' than any other closed design I've tried (I don't count Denon because they don't seal for sh!t). They have a surprisingly large soundstage and open sound for closed headphones, but that being said they still give up ground here to even the 600 which I already content lack a good soundstage. This particularly affects me because I listen to a lot of classical and orchestral movie scores and those types of music benefit from a more open sound. So the soundstage isn't the strong suit of the PSB, but it's quite acceptable and I go so far as to call it very good. Although not 'great' in the grand scheme of headphones, it's very good for this type of headphone. The closed design gives the PSBs greater impact, but you lose some of the air. Playing the two side by side it's obvious, but when I'm out and about with the PSB I don't feel like I'm missing much.
If there were a line in the center of the universe that designated a purely neutral sound, these would be just a tad to the right but they are by no means bright or overly forward sounding.
Overall my desktop rig is better and sounds better, but only marginally better on most material and actually worse on some material. So the desktop rig isn't going anywhere, but the PSB performs MUCH better than I though it would in comparison.
I honestly don't know why this headphone isn't a bigger deal.