We put it up against Bowers & Wilkins' similarly priced
Moving on to the Kronos Quartet, the T 51 p had just the right balance of acoustic warmth and clarity. The P5 sounded nearly as good, with just a tiny bit less body to the sound of the instruments. Both headphones are comfy, but since the T 51 p's round ear pads don't contact as much of your outer ears as the P5's flat pads, the T 51 p is less likely to make your ears sweat in hot weather.
The T 51 p also came out on top against the $349 Phonon SMB-02, another closed-back headphone that's getting a lot of buzz in audiophile circle. The SMB-02 plastic construction looks cheap next to the mostly metal T 51 p, and the bass punch pulsing through the Nine Inch Nails "Hesitation Marks" CD evaporated over the SMB-02s. Switching between the two headphones the T51p sounded considerably more natural and full.
In out next comparison, we put it up against the Sennheiser Momentum, one of our favorite over-the-ear models in this price range (the Momentum costs $60 more). In terms of sound, the T 51 p didn't quite measure up -- the Momentum has a bit warmer sound and bit wider soundstage. Also, the Momentum's cord is detachable and comes with a second cord with a built-in remote/microphone. But we did think the T 51 p was more comfortable for longer listening sessions.
Stepping down to the smaller Momentum On Ear ($199.95), the T51p came out ahead, delivering slightly richer sound and once again coming across as more present and immediate sounding. Of course, sound is a matter of taste, and T 51 p's sound profile won't appeal to everyone (editor Ty Pendlebury, for example, found its sound a touch cold for his tastes).
This is a compact audiophile headphone that's well-built and delivers top-notch sound. Its design may not be for everyone, but it is comfortable and eye-catching. For better or worse, it doesn't have an inline remote/microphone (some people won't care, others looking for a day-to-day headphone to use with their smartphone may wish it had this feature), but other than that small gripe, the T 51 p is one the best on-ear headphones we've tested in a while.
Editors' note (June 13, 2014): The rating on this product has been updated (raised from 4 stars to 4.5 stars) to reflect changes in the competitive landscape.