I already forgot.. besides adding wool and felt I also installed a notchfilter around 4kHz and this made it better sounding to me, yet not good enough to keep it.
Sold it and the new owner reported back he was really pleased with it.
He doesn't know it wasn't a 'standard' CAL!

(strange, I cannot edit my previous posts, only quote it, but can edit this one)

LOL at the buyer not knowing it wasn't standard, but they're better off either way. I'm curious why you left that info out, haha.

I left the modded part out because:
A: Some people think the asking price would be too high because of 'added value' and start to haggle even more.
B: Some people hate the idea some 'idiot' changed something which might be for the worse (does happen).
C: Some people like their purchases 'as new' and not 'taken apart and altered'.


I think the 'do not tamper with your old posts' idea is because of recent events when people claim to NOT have mentioned something and subsequently removing those parts.
I do find it limiting though.... not being able to correct something afterwards or edit it if something was an error in hindsight.
Certainly for not native speaking folks (like me)

Hello. Here to talk to myself a bit and try to wrap up my thoughts on this headphone.

After listening to the CAL in their previously modded state, I found the treble was a bit sharp and harsh sounding at high volumes or over long listening sessions. I threw some drawer liner in the back of the cups, on top of the adhesive foam. But, my primary change was that I added a 1-ply layer of tissue in front of the driver (foam disc in front of that). This makes the overall sound a bit less powerful sounding (airflow sounds/feels more constricted), but it did seem to help smooth out the treble. I like it!

One thing I'm really happy with is that they seem to do quite well at low volumes. Bass still has punch and detail (i.e. still sounds dynamic). Micro-details are a bit buried, of course, but overall clarity is pretty good. I am currently using these at work, as they don't isolate extremely well (I can hear myself typing, can hear coworkers quietly trying to get my attention, and can even hear the quiet hum of the air conditioning), yet they don't leak like an open headphone would and annoy those around me. I can clearly hear my music across the spectrum and am still very aware of my surroundings.

And I usually don't listen to headphones quietly...just can't get into it. Not so with the CAL. With some amps, though, it's hard to set the volume low because the CAL is fairly sensitive (ex: UHA-6S runs into channel imbalance issues at these low volumes).

They do OK at higher volumes, but I suspect distortion starts to become a larger factor, and I still think there's a hint of ringing in the upper mids/treble that is not apparent at low volumes.

I'll contact purrin in the near future and see if he'd be interested in measuring these and the UE6000.