The Abyss AB-1266 Phi headphones are among the finest headphones on the planet. Manufactured in USA, almost entirely in-house, using proprietary techniques, highest quality materials and patent pending technology. The more I listen to them, despite my preference to avoid superlatives in this highly subjective world of hi-fi, I want to say “to hell with it… these are the finest headphone.”. Were it not for a couple of caveats (see below), I would feel very comfortable defending that stance against any other headphone.
When you first set eyes on AB-1266 Phi headphones you think they’re going to be a big, bombastic, over the top headphone. The truth couldn’t be more different. They are refined, natural, sweet; everything they don’t appear on the surface. Sure, if the music is big and bombastic, then that’s what you get. But play some subtle acoustic music and the headphones just melt away.
The detail recovered is beyond anything I have heard, but without any of the grain typically present in other highly resolving transducers. The sound is incredibly smooth. This highly elusive paradox of detail and smoothness is very compelling and something I had only previously experienced on occasion with the top-of-the-line Stax models. Particularly notworthy is the bass which extends deep and clear way down into infrasonic teratory. As a double bassist I'm rather fussy about and attuned to the low end. The AB-1266 Phi produces not the usual cloudy bass we are accustomed to in many headphones, but a truly defined, detailed bass with an uncanny physical presence. I haven't experienced this in any other headphone. And what's particularly striking is that this full, powerful bass doesn't muddy up the rest of the sonic spectrum. Sublime.
In terms of overall frequency response, my gut feeling is that these aren’t particularly flat (I sense a broad scoop around 4kHz?), and there is a discernable “warmth” (or if I’m being ungenerous “congestion”) in the low-mids, which sometimes I notice, sometimes not. I think the cause may be the earcups. Whatever the case, all these non-linearities don’t detract from the music in any way.
A few years ago I recall testing recording pre-amps. I became obsessed with capturing the true attack of a snare drum (yes, I know, “get a life”, right?). Well, anyway… only the very finest microphone and preamps seem to be able capture that very first transient and much of the success comes down to a) thinness of the microphone’s diaphragm and b) the mic pre-amp’s slew rate. However, slew rate is not the be-all and end-all. Sometimes you have a mic/pre-amp combo with amazing speed (fast rise time), but awful tonality. It’s only the very rare synergistic combinations of mic and pre-amp where you get both.
In other words, even if you do capture this speed, only a select few speakers/headphones are able to recreate it. When paired with the correct amp, these Abyss headphones with their extremely thin low-mass driver appear to do both (tone and speed) with grace and elegance. Which brings me to Caveat 1.
Caveat 1: the amplifier.
A headphone is only as good as its headphone amplifier. This is particularly true of the AB-1266 Phi which is quite a challenge to drive. Indeed, JPSLabs (the parent company behind Abyss) have identified this issue and in collaboration with XI Audio are bringing to the market an amplifier specially tuned for the AB-1266 Phi. But that isn’t to say you need to spend a fortune on an amp, only that you need to be aware that not all headphone amps are created equal. I had good success with the reasonably priced Unison Research SH as well as the headphone output on the Yamaha AS-3000. Also, a high degree of success with my trusty, long-in-the-tooth Lavry DA-10 headphone DAC. In simple terms, the better the amp, the more you get from these headphones; with the Phi we have a rare case where the amp is the bottleneck, not the transducer.
Caveat 2: it’s all in the fitting.
Depending on how you adjust the headband and rotatable cups, the sound ranges from mediocre to sublime, so it is really worth dedicating some time to getting them sitting well.
There is a bit of effort involved in finding the right fit; it took me a couple of days of experimentation to feel comfortable and settled. There are four discrete areas of manual adjustment and one area of automatic adjustment. The headband manually expands, as well as angles forwards or backwards, and individual earcups can be rotated to provide the appropriate seal… the key being to get it neither too tight, nor too loose.
Incidentally, I found it uncomfortable to wear these headphones while wearing my rather thick-legged spectacles (and the slight opening in the earcup they introduced effected the sound negatively). This is not something limited to the AB-1266 Phi, but some headphones are more forgiving of eyewear than others. And also related to fit, I should point out that if you are lucky enough to have a thick head of hair (as I decidedly do not), particularly if it is long or curly, then I can’t help but wonder how these headphones might sound. I think it would be difficult to get a good fit.
Put it this way: the importance of experimenting with how these headphones fit can’t be overestimated. When I first placed them on my head and heard music through them I was distinctly underwhelmed. After some persistence and adjustment I’m positively overwhelmed.
To summarise, if you can work through Caveat 1 and 2, then these are surely the best headphones in the world. There. I said it.
Some may balk at spending big money on a headphone and headphone amp, but I would say this: the Abyss AB-1266 Phi in combination with an excellent headphone amp (and equally excellent source, of course!) presents music in the most highly resolving, addictive fashion; up there with the very finest hi-fi I have heard at any price. I have now listened to an extremely broad range of music through these headphones, from acoustic folk through to avant electronica, classical to jazz, singer-songwriter to Afro-beat, the full gamut. I can honestly say that once I got the fit right, recordings through these headphones sound as good or better than through anything else I have experienced, with more detail (without fatigue) and involvement than I previously imagined possible. I would posit that the AB-1266 Phi may even be beyond hi-fi, with good recordings sounding so effortless and natural it’s not like listening to hi-fi at all. Certainly you’d need to spend at least quadruple the amount on loudspeakers and amplifier to approach the same level of reproduction.