I received my CD900ST (with Yaxi pads) from
@LaCuffia a few months back and I'm really enjoying them so far. I figured I'd contribute to this much-needed appreciation thread by posting my impressions that I wrote a while back. The following impressions are with the stock pads.
Comfort & build: The pads are thin, but rather soft and more comfortable than I thought they'd be. With that said, the earhole is on the small side and the headphones feel more on-ear than over-ear. Still, I can find myself wearing these for several hours before my ears start to get sore. The CD900ST is extremely light, especially in comparison to my ZMF Blackwoods, and they seem to have just the right amount of clamping force. The headband padding is perfectly adequate for a headphone as light as this, and the overall build quality feels really solid. They also look rather beautiful - I really dig that silver trim.
Bass: It's there when it really needs to be. Sometimes it feels lackluster, other times it kinda hits you out of nowhere. Extension isn't bad but certainly isn't impressive. Overall, there isn't a lot of bass, but what does exist can be quite punchy.
Midrange: This, in my opinion, is where the CD900ST shines. These are my favourite mids I have heard in a closed-back pair of headphones so far. They're rather forward and extremely detailed. Female vocals sound fantastic; so intimate but never sibilant, unless it's in the recording itself. They're somehow in-your-face but somewhat gentle at the same time. Male vocals are a touch more distant, often placed just behind most instruments, like guitars (especially electric), but still sound great. Speaking of which, guitars have a nice bite to 'em, too.
There's a strange phenomenon that a couple of people and I have noticed in relation to the CD900ST's midrange: its presentation seems to vary noticeably from song to song. This is especially apparent with vocals. What I mean by this is that the vocals on two songs by the same artist, on the same album, can sound like they're being presented in totally-different fashions. At first this may seem like a silly statement, since recording conditions vary from song to song and there are naturally going to be differences that you can hear with various pairs of headphones, but the CD900ST manages to highlight those differences so prominently. This makes sense, given the CD900ST's design and purpose as a studio monitor, but it was still a surprise to hear just how well the recording conditions are reflected through these headphones.
Treble: Surprisingly relaxed. It may be because I was expecting these to be quite bright, but the treble is actually kinda laid back, excluding the 10k peak. I thought this was going to be a somewhat fatiguing pair of headphones, but I haven't found that to be the case. The lower treble may be slightly aggressive at times and there's that 10k peak for sparkle, but I can find myself listening to these for a very long time without a care in the world.
Soundstage is, of course, intimate; everything sounds like it's taking place directly inside my head. With that said, there's still a strange sense of spaciousness within certain recordings. Little details are brought out with these headphones: breathing is a big one, of course, but plenty of smaller details like the vocalist's distance from the microphone, the amount of natural echo in the recording environment etc. are more prominent with these headphones than they usually have been with others I've tried. Imaging is excellent. Really excellent. Left, right, centre. Quite accurate, really. I think I might even try these out for gaming. As strange as that sounds, I think these would do a good job when it comes to positional audio.
These headphones sound wonderfully unique, and there isn't a thing that I would change about the sound. The pads, however, could be more comfortable. Enter the:
Yaxi Pads!
Comfort: These pads are
so damn comfortable! The ones in particular I have are the protein leather Yaxi Pads, but note that they also make microfibre pads (I'd like to try them, actually). These pads make the CD900ST actually feel like a true over-ear headphone. The protein leather is so darn soft! These are amongst some of the softest pads I have had the pleasure of caressing. Super soft protein leather + lightweight CD900ST = comfort for days. I could wear these forever.
So the Yaxi Pads are obviously a huge upgrade in comfort, but what about:
Sound quality: Not only did the pads immediately make the CD900ST more comfortable, but they also immediately changed the sound signature in a few ways. It seems as though there's more bass but there's also less bass at the same time. What I mean by that is that I can
hear more bass but I can
feel less. It's as though there's more bass present, but it just doesn't hit as hard. In fact, it feels as though it doesn't 'hit' or 'punch' at all, which may just be due to an increase in distortion. The midrange is a touch more distant and the upper mids just feel a bit off. I also noticed that certain vocals and instruments are noticeably harsher and border on more of a slightly sibilant sound than before. This makes for a less-relaxing and more-fatiguing sound overall. Soundstage is also slightly less intimate. Don't get me wrong, I still like the way these headphones sound (and I love the way they feel) with the Yaxi pads equipped, but they just don't sound
as good as they do with the stock pads.
I believe
@Ishcabible said it best when he said that the Yaxi pads "take away what makes the CD900ST special"
Speaking of which, Ishca actually took some measurements on his admittedly-flawed rig before sending the headphones off to me (he was essentially acting as a middle man between LaCuffia and me) and those measurements pretty accurately line up with what I hear. Once again, his measurement rig isn't perfect, but it still serves as a good indicator as to what kind of audible changes have been made between the two pad configurations.
Since I haven't used this account enough to gain permission to directly post images, I'll just leave the link to the measurements here:
http://imgur.com/a/1CtpC
(Green = Yaxi)
Glad to see them get some love and upgrades (not that they didn't before, I was just not always in an environment where I can use them comfortably). The have the most unique soundstage I've experienced. It's somewhat collapsed (if it's the right word) but not small/closed-in like some cheap headphones. I guess it's because of how the bass and mids are tuned. Neutral but not boring at all, which is a hard feat to achieve.
