Astell&Kern AK T5p 2nd Generation headphones

Astell&Kern is known principally as the creator of extremely high-quality digital audio players. It has strayed into home audio and assorted network devices, but its bread-and-butter has been DAPs. If that were you, how would you go about creating headphones presumably optimised for your products?

Hey, if headphones aren’t really your expertise, why not go to one of the most prestigious headphone companies in the world for help? The Astell&Kern AK T5p 2nd gen headphones are a collaboration with the German firm Beyerdynamic.

Astell&Kern AK T5p 2nd gen headphones

So, how did they go?

tl;dr

  • Over-ear, closed-back headphones.
  • Developed in collaboration with long-standing (established 1924) German headphone specialist Beyerdynamic.
  • Made in Germany.
  • Dynamic driver (size not stated) employs Beyerdynamic’s “Tesla Technology”, which provides “the power of more than one Tesla”. I’ll explore what that means below.
  • Unusual driver orientation has them set slightly forwards of the ears, and angled back by perhaps ten to fifteen degrees, presumably attempting to more closely replicate the sound provided by speakers which are, of course, typically in front of the listener.
  • Provided with 1.4 metre detachable cable (two 3.5mm stereo plugs at the headphone end) terminated with 2.5mm TRRS balanced plug suitable for use with balanced output socket on Astell&Kern (and several other brands’) players. Short 2.5mm balanced to 3.5mm unbalanced cable included, along with 3.5mm to 6.35mm adaptor.
  • Hybrid conductors made from silver and silver-coated strands.
  • Specified frequency response: 5 to 50,000 hertz.
  • Impedance: 32 ohms.
  • “Nominal sound pressure level”: 102dB.
  • Specified weight: 340 grams.
  • Provided with high quality, rigid carry case.
  • Fine sounding closed-back headphones. Excellent tonal balance. Solid bass. Easy to drive. And only slightly affected by high impedance outputs.
  • Available from quality high-fidelity retailers and online here.
  • Price: $1,699

Astell&Kern AK T5p 2nd gen headphones

More on the Astell&Kern AK T5p 2nd gen headphones

Even though Astell&Kern is known mostly for its portable gear, the AK T5p 2nd gen headphones do not look like they’re designed for portable use. The 340-gram weight is by no means heavy, but it is significant. The full-sized over-ear earcups can’t swivel flat for less voluminous storage. They look like proper, high fidelity headphones. Which, as we’ll see, they most definitely are.

And they are very nicely constructed ones. The headband seems to have a brushed aluminium spine, with generous padding on its underside and around the earcups. I found these headphones a very comfortable wear, even after many hours. The case will certainly keep them safe when you’re travelling, although it will chew up a significant amount of carry-on luggage volume .

Electrically, though, the AK T5p 2nd gen headphones seem to be optimised for use with portable players. The 32-ohm impedance strikes me as a good choice. Typically 16 ohms is the minimum with which a lot of headphone amplifiers are comfortable. So most should find 32 ohms an easy load. Indeed, I’ve seen at least a couple of headphone amplifiers which provide maximum output power into this impedance.

The lower the impedance, the higher the power for a given voltage (assuming that the amplifier can deliver the requisite current).

Astell&Kern AK T5p 2nd gen headphones

I really, really liked the supplied cable – not for sound but for sheer aesthetic pleasure. Yes, it employs “4N pure silver and 7N Occ Copper hybrid” to get the signal to the drivers unmolested. Nice. What I liked was the weave, since each conductor was in its own transparent sheath. Two of the four conductors were clearly copper. The other two featured the silver layer over the copper.

Standard 3.5mm stereo plugs are at the two headphone ends of the cable. Which means that should you want to change cables, there an enormous number of alternatives available. The 2.5mm TRRS plug on the end of the cable works with A&K digital audio players (LINK). Adaptors provide for regular 3.5mm and 6.35mm connections.

A&K says that the Beyerdynamic “Tesla” technology employed by the AK T5p 2nd gen headphones provides “the power of more than one Tesla”. A Tesla is not a measure of power, but of magnetic flux density. Since loudspeakers and headphones depend on their electro-magnetic engines so much, I suppose a higher level of magnetism would be a good thing. So, how much is a Tesla? Wikipedia tells me that a fridge magnet typically has just 0.005 Tesla. And that a proper dynamic loudspeaker is generally between one Tesla and 2.4 Teslas. I think it’s safe to assume that a magnet strong enough to control, perhaps, a 300mm woofer, might also be good enough to control a, perhaps, 40mm headphone driver!

Astell&Kern AK T5p 2nd gen headphones cable

Listening

My experience of Beyerdynamic headphones is really quite limited. By limited, I mean limited to one set. For some months a year or so ago I used Beyerdynamic Amiron Home headphones as one of the three or four headphone models I’d cycle through for my own private listening. They were wonderfully detailed and open and verging on magical. But against those characteristics … they were excessively bright. Indeed, in one comparison review of headphones priced up to around $1,300, I wrote that they were the best. But I would have liked that best to have the treble peak tamped down a little.

That kind of thing worries me. Was that a Beyerdynamic “house” sound?

Well, if it is, the AK T5p 2nd gen headphones don’t share it.

These are closed-back headphones, so they don’t quite have that wide open airiness that good open-backed headphones offer (the Amiron Home headphones are open-backed.) But they still deliver truly penetrating detail into recordings with a tonal balance that is far closer to what you’d expect from quality loudspeakers.

Astell&Kern AK T5p 2nd gen headphones

Let me lay out some impressions: I was recently inspired to revisit the 1974 This is the Moody Blues compilation album. My CD version is far from exemplary … or maybe it’s a bit too transparent. I love early progressive rock, but can barely tolerate the Mellotron that too many of the groups used for a vaguely string-like sound. Now, what was that horrible sound, overlaid on a gorgeously clear rendition of the vocals and drums on “New Horizons”? I suspected a Mellotron, but a bit of research reveals that it was a “Chamberlin”. That turns out to be a “precursor” to the Mellotron. (I’m guessing the Chamberlin was something of a show-off item by this time. The highest selling model, the Chamerblin 600/660, had sales figures of somewhat over two hundred units.) Oh well, time to move on to some different music.

(But before I do, I have to say that the AK T5p 2nd gen headphones did a remarkable job with the relatively soft bass on this album. I could hear – and enjoy – the character of the bass’ speaker-amp. Nice.)

Now, some more listening impressions with more appropriate material.

“Isobel” on Dido’s album No Angel opens with some fascinating percussion overlaying a distant harmonic accompaniment. There was a great tangible presence on the whole of this. The layering and separation of all the elements of music into individually perceptible items – individually perceptible, but without losing the coherence of a musical whole – was impressive. And to the extent that you can have a realistic soundstage with headphones, the AK T5p 2G headphones managed it. The track “My Life” opens with a tick of a cymbal and a kick drum. This semi-isolated kick was nicely solid, controlled and quite devoid of any untoward harmonics.

Astell&Kern AK T5p 2nd gen headphones

For some reason the weird, semi-comical, bass-led band Primus isn’t used much by reviewers. Silly reviewers. Primus’ recordings are crowded with activity, but are (like Rage Against the Machine’s) also full of space, supposing the playback equipment is capable of delivering sufficient control. The AK T5p 2nd gen headphones were more than capable of that, keeping order throughout Sailing the Seas of Cheese. Indeed, there was remarkable air – sometimes they seemed almost open-backed – and a subtle control. The bass guitar descent around 4:20 into “Those Damned Blue Collar Tweekers” was … perfect. Some headphones fake deep bass by emphasising mid-bass. No, the bass balance was exact, and maintained into the lowest registers.

I could go on, but I’d be more or less repeating myself. I listened also to Justin Timberlake’s latest, Grand Funk Railroad, a lot of King Crimson – much of it in high resolution – Glenn Gould rendering Bach and Mozart on piano, and some Beethoven piano concertos on early instruments. With all, these headphones simply delivered excellent transparency and insight into the music, holding nothing back.

Measurements

As usual for headphones, the only objective test I conducted was to measure the frequency response of the signal delivered to the headphones by a high output impedance device. How high? Around 470 ohms. There’s a surprising amount of gear out there which actually does impose such high output impedances.

The impedance of the AK T5p 2nd gen headphones does indeed vary according to frequency, but by a surprisingly small amount. The net effect is a variation of less than a 3dB range across the full frequency spectrum. There’s an almost 1.8dB boost at around 80-90 hertz, a minimum level of -1.1dB at 3kHz and a short +0.2dB peak at 7kHz. You can see all this in the graphic, thus:

How internal impedance affects voltage delivery

These things work proportionally. If you use an amplifier with a 47 ohms output, the frequency variation will be less than 0.3dB; if it has 4.7 ohms, less than 0.03dB. And so on.

So, maybe? not absolutely ideal for super high impedance outputs. But for anything within reason, not a problem. And for Astell&Kern players, with their low output impedance, certainly not the slightest of problems.

Conclusion

Well, I suppose the Astell&Kern AK T5p 2nd gen headphones may have been designed principally for use with Astell&Kern’s excellent portable players. And a lot of my listening was indeed using the Astell&Kern &Futura SE200 via the 2.5mm balanced connection. But much of it was with fine quality desktop gear, such as the iFi audio Zen Can headphone amplifier, the SPL Phonitor xe headphone amp, along with some other less salubrious equipment.

And with all of them, the headphones delivered.

Astell&kernClosed-back headphonesOver-ear headphones