[WaveTheory]

Interesting review, however I disageee with the part about the "bass frequencies making their way out of the headphone and back in through the gap."

It actually makes perfect physical sense. As frequency goes up, sound waves become more directional. With speakers/subwoofers, the bass driver(s) are almost always built into an enclosure because low frequency waves are nearly omnidirectional. Since the driver pushes air in both directions, the back wave is 180 degrees out of phase with the front wave and of the same magnitude. Thus, below ~100 Hz you get near-perfect phase cancellation. Building a box around a woofer allows for trapping and controlling the back wave so that such cancellations don't happen.

It's actually quite common with open-back headphones to get a bass bump - the bass peak Lachlan mentions and measures in his review - when the seal is broken. The same happens with HiFiMans and Audezes when their seal is broken. Why? Diffraction, ie waves bending around obstacles. The back wave can escape through the outside of the headphone cup but it also has to bend around the enclosure of the headphone and the pads before it reaches your ear. This bending around messes with the time alignment of the front wave and back wave enough that they no longer perfectly cancel. Instead, a tight range of frequencies will get a noticeable bump through constructive interference and then outside of that there will be decreased sonic energy due to destructive wave interference.

The reason that headphones have "minimal bass" as you put it comes down to physics again too. Low frequency sounds require more energy than middle and high frequencies to reach the same sound pressure levels. One way to increase that energy is to increase the area over which a vibration happens, thus pushing more air. This is why in speakers woofers are bigger in area than mid and high drivers. The problem with headphones is that there are practical limits to driver size lest you get into comical Jecklin Float territory. Headphone bass still sounds quite strong though because of how close the driver is to the ear. You can get away with less energy pushing bass frequencies when the bass only has to travel a couple of cm.

That said though, the sound going out of the TC and coming back in certainly applies to the mid and high frequencies. If you can hear the headphone playing music when it isn't on your head, then every sound that you CAN hear from this point will make its way back in when you do wear it. He totally got that backwards. Every open headphone does this, including speakers.

Yes, but I think there is another misconception here too. As frequency goes up, more and more of the back wave content that returns to the ear is going to be due to reflections. Especially in the treble, which gets very directional especially above 10KHz, some portion of the back wave will reflect off the inside of the grille on the backside of the driver and be directed into the ear. This is going to create wave interference again. Back to speakers again to help us understand, sometimes this reflected back wave is desirable. Some home theater enthusiasts swear by using dipolar surround speakers. Those intentionally let the mids and highs travel both forward and backward 180 degrees out of phase so that the back wave reflects off the walls and reaches the listening position a little while after the front wave. The result is a more diffuse soundfield with less pinpoint imaging. Fans of this approach say that the position of the speaker becomes less detectable this way and the overall presentation becomes more enveloping. Some speaker makers have used similar approaches or bipolar designs (sound completely in phase going forward and backward simultaneously - which requires an enclosure and multiple drivers) for speakers made for music listening because some listeners like the effect.

I applaud Abyss for trying something different. Leveraging the bass bump Lachlan measured is a unique approach in headphones. It has advantages. The Abyss bass presentation can be loads of fun. They arguably - within a specific frequency range - bring an unmatched combination of bass quantity and quality. But there are tradeoffs to their sound. Lachlan covered many of them. I personally find their midrange resolution and timbre to be WAY behind similarly priced competitors. That alone is a deal breaker for me. Add in that the 1266 series does not stay on my head hardly at all unless I sit there as still as a headphone stand and then they just get generally uncomfortable quickly and I find them hard to recommend. But that's just me.

Cheers

 

[paradoxper]

Could care less. Heard it all. T2 and SGL are in the territory of 1266 TC performance a weird gap emerges with TC 300B combinations.
The same for the CA1a which is revelatory from a price and what your reference is comparatively.

In 10 years time, nothing is going to surpass the TC nor incrementally meaningfully improve it. A extra resolution won't cut it. The drivers are encompassing a limitation
and the materials of tomorrow haven't quite caught up yet.

Still TC gives the ah and wow moments and leverages the more complete balance of sound. They will reveal your entire chain with ruthlessness.

 

[MacedonianHero]

I've owned the Abyss AB1266 Phi TC for several years now and tonight I decided to put on Dave Matthews' latest album (Chord DAVE --> Enleum AMP-23R) and these headphones never cease to amaze me! Simply magical...speaker-like presentation with incredible detail retrieval and such an enjoyable audible experience!!! Definitely among the very best headphones I've had on my head...like ever.

 

[jlbrach]

Could care less. Heard it all. T2 and SGL are in the territory of 1266 TC performance a weird gap emerges with TC 300B combinations.
The same for the CA1a which is revelatory from a price and what your reference is comparatively.

In 10 years time, nothing is going to surpass the TC nor incrementally meaningfully improve it. A extra resolution won't cut it. The drivers are encompassing a limitation
and the materials of tomorrow haven't quite caught up yet.

Still TC gives the ah and wow moments and leverages the more complete balance of sound. They will reveal your entire chain with ruthlessness.

what he said!

 

[PhazeCrive]

Yeah for sure, Wave Theory. I wasn't getting too into the nitty gritty with the super technicals. I was mostly saying "for the most part." The bass leakage from the backwave does make it back in, true, but it's not a crazy amount. That's not to say no bass gets back in. Kinda like how some parts of a room will have next to no speaker bass, but other spots have a ton due to the acoustic reflection buildup at the corners. Experienced that yesterday when my neighbors were blasting bass. The difference of me moving a few inches made a world of a difference to how loud the bass was due to the walls.

The main reason for the increased bass from the 1266 gap is because of the increased air flow. (And heat, since heat loosens up the drivers for some reason.) Like your nose, the TC needs air to breath. More air, more excursion. This is why it will start to distort and undergo heavy excursion when it's off of your head. That is the main reason for bass increase, I believe, and a very small bass increase also comes from the backwave re-entering. The backwave is only made stronger due to the increased excursion which comes from more airflow, but it's definitely the excursion aspect that contributes far more to the bass output.

 

[PhazeCrive]

I haven't put up much 1266 impressions even after having owned for over a year. It's been a journey and most of it was pretty underwhelming -- due to my own neglience, however.

I started off with just the TC running a line out from my phone. Amazing presentation even from that but I still wanted more. Upgraded to a Topping stack but still didn't quite like it. Upgraded to a Burson GT and Gustard X26 Pro. Now we were getting somewhere but I still wasn't happy, so further upgraded to the FS/P. And folks, this still was not enough...or so I thought because you see, my main issue with the TC all along was the fit. I've seen the Abyss fitment videos, but just went with was more comfortable or something that contoured my head perfectly but with a gap...BIG MISTAKE.

When Joe says you want the thick part in the back, you do. I thought that was just his preference but it's really true. Having the thick part of the pad behind the ear really traps a ton bass that otherwise normally escapes, and as a glasses user, there's really no other way, otherwise you introduce too much gap and rolloff. The only other way is to just wear the headphone tight as hell which hurts. Having the thick portion in the back solves everything and now I've finally been able to actually enjoy them as of 6 months ago. Literally 10 times out of 10 in the 12 o'clock position, eventually I would always get bass unevenness. Super frustrating and annoying to have to mess with the fit and bend the frame to get it perfect again only for the unevenness to reoccur next session! Such instances have made me list the TC for sale numerous times. Little did I know that rotating the pads one notch would solve everything. Just wish it didn't take me a year to do that. Don't be me lol, start off at 11 and 1 o'clock. Haven't messed with the fit in over 6 months and it's perfect every time now.

It's really beautiful sounding. Can easily make me get emotional with its space, detail, clarity and bass. Now it just goes sooooooo low but with such slam, rumble and cleanliness to the bass I haven't heard too much even after a year of owning it. I used to be a basshead, and still am but the TC has turned me into a treble head. I can never get enough of that speedy detail layer.

Like what was mentioned above, there probably will not be anything that will meaningfully improve it for a long time, and I find it hard to even figure what that would sound like. It's already spectacular and you'd be hard pressed to find something better unless you are a mids maniac.

 

[Ragnar-BY]

After a lot of listening, comparisons and reflection, I changed the stock cable for Lavricables Grand. Pure silver sounds great! Here is my review.

 

[Abyss Headphones]

It's actually quite common with open-back headphones to get a bass bump - the bass peak Lachlan mentions and measures in his review - when the seal is broken. The same happens with HiFiMans and Audezes when their seal is broken. Why? Diffraction, ie waves bending around obstacles.

Being an open back headphone really has nothing to do with this. It's the nature of a planar transducer, and it's obviously not well understood, seems it's always lumped together with the likes of a dynamic speaker. Knowing how these differing transducers operate by design and are utilized to produce music tells why it does what it does under different operating conditions. Same with a measurement device (microphone) and how it's used to measure acoustic pressure, you need to understand what the microphone is actually measuring (or not).

More air, more excursion.

Exactly!

 

[Ragnar-BY]

I don’t know how much my feelings correspond to reality, but it always seemed to me that the AB1266 not only play the bass “louder”, but that these headphones are able to move more air and faster than others. And that's what makes this great bass. It reminds me of the difference between 8" and 15" subwoofer. A small driver can be made to play quite loudly at a certain frequency, but the overall feel is completely different.

 

[Abyss Headphones]

Yes, but I think there is another misconception here too. As frequency goes up, more and more of the back wave content that returns to the ear is going to be due to reflections. Especially in the treble, which gets very directional especially above 10KHz, some portion of the back wave will reflect off the inside of the grille on the backside of the driver and be directed into the ear. This is going to create wave interference again.

Should add that this is why so many headphones have a more forward midrange. This immediacy is in part brought about by reflections of the materials within the interior. These reflections also happen to be what people are accustomed to hearing. Take this away and at first listen it's different. Just like moving your speakers into a new room, have to give the brain a good month or so to adjust to the new acoustics.

AB1266 was designed to duplicate the sound of top shelf loudspeakers with subs in well appointed listening room, in as such unlike 99% of headphones it has minimal rear wave reflections to color the sound. In fact one of the reasons we used foamed aluminum was that in this particular headphone design it has similar qualities to nothing on the back-side at all, as in acoustically open to the driver.

To people who tend to be strictly headphone users (little or no experience with a properly set-up 2 channel system) this may present itself as more laid back in certain regions of the frequency spectrum, but in essence the vocals, drums, etc. come from a more distant not-in-your-face perspective due to added [nay infinite] depth to the soundstage outside of your head (not the typical width and height only). This acoustic perspective is adjustable by the fitment, and as many here will tell you this is an important thing to spend time understanding. For example, if want to key in on vocals moreso, try moving the headphone back slightly on your head, in other words move the front of the driver toward the center of your ear.

I did a video on how to fine tune your AB1266 a while back...

 

[vonBaron]

I tweak my 1266 setting, now bass rumble like it should.

 

[Jawbone]

Hi chaps.

I've just purchased a set of OG 1266's and the 'classic' headband sagg is evident. Did anyone find a reasonable alternative to buying a new one? I've had to twist the headband around twice to get it to stop hitting the top bracket, I expect it's about 5 seconds from snapping!

 

[PhazeCrive]

Looked ridiculous but a free and immediate fix I used to do was stick a hand towel above or below the headband to prevent sag or drooping.

The root issue of that though is likely the O-rings. You'll need a different pair..

Edit: But I find stock O rings perfect.

 

[nogi replicant]

I do think this O ring situation for the old headband is not good considering the price of the headphones. There should be a more cost-effective solution available from Abyss as opposed to shelling out significant $ for the new headband (having owned both I find the old one just as comfortable as the new one - and personally prefer the look of it - whilst not as plush looking I dig the old writing on the top). They may not have been aware at the time of original design that their robust O-rings would eventually fail. They should not have gone with the sewed up ends on the original leather band. But I expect that a company as switched on as these guys could have concocted some replacement mechanism that could attach to the original headband. The user community have come up with all kinds of dodgy solutions (such as mine lol).

 

[smodtactical]

Damn pretty negative review of 1266 tc