I've recently purchased some new cans and thought I'd share my impressions.
15" Mid 2012 Retina MacBook Pro (10.8.2)
Kawai CA95 Digital Piano
Beyer T1 (600 Ohm)
Beyer DT-990 Premium (32 Ohm)
Sony MDR-V900 (24 Ohm)
Bose QC2 (24 Ohm?)
Kawai CA95 Digital Piano:
I couldn't find a clear answer on the Internet as to whether the CA95 headphone jacks could drive a high impedance headphone such as the T1. Let there be no doubt: It can, and easily. The T1 sounds incredible straight out of the headphone jack. Even on the Low Headphone Volume setting anything past 60% volume starts to hurt my ears.
The FiiO E09K makes no discernible difference to the quality of the sound of any of the 4 cans I've tried when plugged into the Kawai CA95.
The Retina MBP easily drives the 24-Ohm Sony and Bose cans.
The DT-990 Premium 32-Ohm cans sound decent plugged directly into the headphone jack of the Mac. But the DACPort substantially improves both sound quality and output volume. I think the MacBook Pro can drive 24 Ohm cans but anything beyond that will cause SQ to diminish.
The DACPort is great! Small, well built, truly plug-and-play. The only downside is the Mac's volume switch doesn't control the DACPort so you must use the DACPort's volume control. I highly recommend the DACPort.
Using AirPlay and listening through the Onkyo SR607 also improves SQ over the Mac jacks.
Onkyo vs DACPort: No discernible difference. Both are fine amps to my non-audiophile ears.
My first "real" pair of cans. I bought these back in 2002 for $300. So this is the standard to which I compare headphones. It's what my ears got used to.
These aren't very comfortable for wearing for long hours. The cups get sweaty and after an hour I feel the need to take them off and rest my head.
Loud but blurry bass; not crisp bass, but a little soft. Flat and dim mids and highs. The bass resonates and spreads out and overwhelms the other sounds.
On the Kawai CA95, these cans do not fully illuminate the lower octaves. The lowest A just doesn't feel very strong. The middle octaves are ordinary. The high notes are small and tinny.
The main reason for their existence is to listen to music on airplanes. For that they excel.
The ear cups are small, and they cover my ears but just barely. Wearing glasses, the cups allow for the arms of the glasses and help secure them in place. The Sony's cups interfere with my glasses which is annoying when trying to read music.
Wearing for hours, the cups get sweaty, but because of their smaller size, I can wear the Bose for hours without fatigue or discomfort.
The mid and high ranges are not good at all. Dull, flat, muted. Much worse than the Sony MDR-V900. Lots of muddy, booming bass, more than the Sonys, but also a little crisper.
On the Kawai CA95 the bass is responsive but fairly muddy and not very sharp. The octaves above middle C sound unimpressive. The high notes are tinny and small. In fact, it was the sound quality of these Bose QC2 cans on the CA95 that made me realize I had sh*tty headphones; I suspected I wasn't hearing the full potential of the splendid CA95 digital piano.
DT-990 Premium (32 Ohm):
I love the comfort and fit of the Beyers. The DT-990 Premiums are soft and don't interfere with my eyeglasses; the arms are slightly held in place but not firmly.
On the Kawai CA95, the 990 cans sound equally fine straight into the headphone jack, or using the FiiO E09K (which, as far as I can tell, offers no improvement here).
The 990 cans with the CA95 blew me away. The mid octaves sound so crisp, bright and present that I felt like I'd just upgraded my piano -- I'd no idea I was missing that much sound wearing the Sony or Bose. The high octaves -- oh my god. Rather than sounding tinny and small, I was now hearing the delicacies of well-voiced high notes. The difference in sound quality on the higher octaves is like the difference between playing a small console piano vs a large concert grand. Rather than avoiding the high notes, I now find them deliciously enjoyable to play.
The bass on the DT-990 Premiums (32) is the most pronounced of all the cans. Punchier, but a little blurry, lingering in the air. It does not overwhelm the mids or highs.
Listening to music, the bass is punchy and a little blurry, but not in a bad way. The mids are warm. The high notes are bright but a little hissy.
The fit is similar to the 990. I love it. The outside of the T1 is a nicer build quality than the 990s. What you'd expect for the price. The cans look good and feel good.
I'd been listening to the DT-990 Premiums (32) for several weeks before I got the T1. Why did I get the T1? Because I suspected that my piano would sound even better. And I was right.
On the Kawai CA95, the difference between the DT-990 Premium (32) and T1 is immediately noticeable. The bass on the T1 is strong, but not as punched up as the 990. The T1 hits the low notes with strength and clarity. Whereas the 990 is a little muddy on the lows, the T1 is clear and distinct. The midrange notes on the T1 are even better than the 990. More present; more immediate. Moving into the higher octaves, more details and delicacies of the higher notes come through. It's like having fine vision, and then the eye doctor gives you a new prescription which is even sharper and you see everything newly. That's the T1. On most pianos, the lowest and the highest notes are usually the weakest sounding, but on the T1 and the CA95, these notes are so beautifully voiced that they seduce you into playing them.
I'd read some remarks about how high end cans were a waste of money on digital pianos. I completely disagree. If you have a high end DP, you need high end cans. I've never heard a piano sound so good as when listening with the T1. All the notes, from the lowest A to the highest C, are strong and bright and delicate and balanced. The T1 is seductive and intimate. If I'd known, years ago, that high end cans were like this, I would have gladly parted with my coin.
Listening to music with MPB + DACPort + T1 is ecstasy. Noticeably clearer and cleaner than the 990. The bass is strong and distinct; the mids are balanced and warm; the highs are bright but not hissy. I have not listened to the Sennheiser HD-800 so I cannot compare the sound stage aspect.
I highly recommend T1 and the DACPort. And of course the Retina MacBook Pro :)
With the T1, for the first time, I feel like I'm hearing everything.
For listening to music on my MacBook Pro, the DACPort is perfect and easily drives the T1. The FiiO E17 (which I haven't tried) only drives up to 300 Ohm cans, and though it is cheaper, I recommend the DACPort instead.
For my setup, the FiiO E09K doesn't add anything, as the Kawai CA95 headphone amp is powerful. Though the FiiO is well made and I'm not un-recommending it.
The DT-990 Premium (32 Ohm) are excellent cans. An excellent value for their price and performance.
The Tesla T1 are superb cans. Worth the extra money? To my ears, yes. In a heartbeat.