Like anyone who regularly reviews headphones, I've noticed that the majority of them have no unique features or qualities. So for example, it's rare to find headphones in the T 51 P's price class that aren't made in China, but this little $289 Beyerdynamic is made in Germany. The lightweight, 174 gram, mostly metal design doesn't have a hinged headband, but the ear cups fold flat for easy storage in the supplied, beautifully designed carry case. The headphone lacks a mic or inline controls, marking it as a design intended for the serious audiophile who doesn't want to ever lose focus on the music. Impedance is rated at a highish 60 ohms, but the T 51 P sounded great plugged into my iPod Classic and at home with my Schiit Asgard 2 headphone amp.
Isolation from external noise on the NYC subway was good, though not up to the standards set by noise-canceling headphones. Then again, the T 51 P sounds better than any of those headphones and it doesn't need batteries (all NC headphones do). While most audiophile headphones come with one-year warranties, the T 51 P's runs two years. Like I said, the T 51 P stands out from the pack.
The T 51 P's sound balance is slightly warmer than neutral, but detail and resolution are superb. It's a comfortable headphone to wear for hours at a time and still not feel fatigued, and it doesn't favor one genre of music over another. For such a little headphone the T 51 P's big bass sound caught me by surprise. It's not overdone or thick, but if you crave a rich low-end the T 51 P won't let you down.
Brian Eno's ambient recording, "On Land," had a wide-open spacious quality, and it sounded nearly as big as I've heard from larger open-backed headphones like my Hifiman HE-400s.
For me, the T 51 P bested the $330 Bowers & Wilkins P5 on-ear headphones' while listening to Neil Young's recent "Americana" CD; the T 51 P was simply more present/immediate sounding. The P5 sounded recessed and Young's voice was lost in the mix. The Kronos string quartet's sound had just the right balance of acoustic warmth and clarity on the T 51 P, 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.
Next, I briefly compared the T 51 P with another closed-back headphone that's getting a lot of buzz in audiophile circles, the $349 Phonon SMB-02, and the T 51 P scored a decisive win on every count: comfort, build quality, and sound. The SMB-02 plastic construction looks cheap next to the mostly metal T 51 P, and the bass punch pulsing through Nine Inch Nails "Hesitation Marks" CD evaporated over the SMB-02s. Switching between the two headphones the T 51 P sounded considerably more natural and full.
The T 51 P is the best on-ear headphone I've heard in quite some time, and it's highly recommended.