I got these from ProAudioStar on eBay because they were selling open boxes for $199: http://www.ebay.com/itm/Beyer-Dynamic-T51P-Portable-Tesla-Hi-Fi-closed-back-headphones-PROAUDIOSTAR-/400646640811
I thought I'd write a quick review on them since I haven't seen much talk about these anywhere. I also recently bought the Sennheiser Amperior, so Ill compare the two as well. This is my first review ever, so sorry for everything. Here we go:
It came with a 3.5mm to 6.3mm adapter, a cloth case, and an airplane adapter. I won't use any of them.
Compared to the DT1350, the T51p loses the split headband, but gains metal earcups. I prefer this because I don't like split headbands and never split the headbands on my Amperior. Also, I think the DT1350 facelift looks really cheap with the black plastic, although I've never seen one in person. However, the T51p looks absolutely fantastic with the metal cups. There's faint horizontal machining lines on them which impart a great visual texture.
The T51p uses significantly more metal than the Amperior too: everything on it is metal except for the black ring around the earcups, while on the Amperior the only metal parts are the outer earcups, the outer part of the hinge for the split headband, and the metal bar that connects the headband to the earcups.
In terms of size, the T51p earcups are much smaller than those of the Amperior, and I had some trouble figuring out where to place them to get a good seal on my large ears. I had this problem with the AKG Q460 too. The significantly smaller earcup size does mean increased portability, I suppose. I read that these have the same improved earpads as the DT1350 refresh. If so, I can't imagine how hard it was to get a seal on first-gen DT1350s, I had enough trouble with these.
I think the suede Amperior pads are a lot more comfortable than the leather pads on the T51p, although the T51p pads aren't uncomfortable by any means.
First, here are measurements for both these 'phones from Goldenears - the only website I know of that has tested both.
While testing these, I mainly listened to drum'n'bass, blues, and alternative rock. I used iTunes with 320kbps MP3s and WAV files. EQ off. Dell E6520 -> Asus Xonar U3 -> Fiio E6.
Bass: Contrary to its frequency response graph, the T51p does not sound like a very boomy headphone to me. In fact, I would call its bass balanced-armature like: it has very fast decay and is quite clear. It can pick up some bass guitar notes that even the Amperior smears. T51p doesn't have a huge amount of bass but it has an ample amount and this is coming from a basshead who loves his Westone 3 and Future Sonics Atrio IEMs. It's lacking a little of the very lowest frequencies, which is only really noticeable when listening to drum'n'bass. That is to say, they're not loud enough to be clear but you can still tell that they're there. The Amperior has more extension but is also more boomier and impactful. Of the two, the Amperior is definitely the basshead choice. Bass drum kicks have more impact and overall it's a more "explosive" sound, although still more detailed and clear than most.
Midrange: The T51p does well in the midrange. It's lush, and I think the midrange gives the headphone it's addictiveness--sometimes I just can't put these down. It's not intrusive on the other frequencies, and isn't overly accentuated in terms of loudness. Detailed, too--I don't think I've owned a headphone with this detailed of a midrange, but I usually choose V-shaped sound signatures. Which is probably why I don't know what else to write here.
Treble: T51p's treble is not as accentuated as the Amperior's. Amperior has a sharp 8-9kHz peak which the T51p lacks, and it's noticeable when listening. I think Amperior has more treble detail, but that might just be because of the frequency response--T51p's treble is more recessed. The ~4.8kHZ peak on the T51p does help drums cut through the bass and midrange, but also gives it a slight sibilance if you're sensitive to that. To me it wasn't an issue unless I tried to hear it.
Other stuff: They both have small soundstages. I heard this is just what happens with on-ear headphones. Amperior sounds more airy, because it doesn't start dropping off in frequency response until ~3kHz. T51p drops off starting at ~1kHz. If you raise 2kHz in the iTunes EQ by one bar, it gives the T51p a lot more airiness and also unlocks some upper mid/lower treble detail that was missing due to that part of the frequency range being recessed. Finally, I would say that the Amperior is cold-sounding due to its treble but with boomy and well-extended bass, while the T51p is more neutral-sounding with less emphasis on either treble or bass. In terms of overall detail the Amperior has it since as a whole it sounds clearer with less midrange clutter. But the actual midrange of the T51p is pretty great (although it does cover other detail) so I don't know which one I like better yet.
Edited by alexm23 - 1/18/14 at 3:40pm