What if one or two of them was a disc? Would it muffle too much?
Yes, it would... And there would be no additional positive effect at all. I tried perforated or non-perforated discs as wel as different types of foam etc. This just works, the rest does not. :-)
Alas, my czech is rusty. Does all that writing between the pretty pictures include your impressions on the sound with the mods? The csd's seem to improve as well, and I would appreciate hearing what your thoughts are after listening.
Oh, sorry... I thought you would use Google Translator or something if any additional info (other than the graphs or images) would be needed. But of course, you can always ask about anything regarding our website's content, I will gladly comment in english.
Yes, I am basically explaining my subjective impressions of the stock headphone as well as modded one... mentioning that there is not really much else you could do with your headphones (including my opinion on the bass port mod)... and some additional stuff that is not really related to the modification.
In short, the modification is not really going to change the overall character of the headphone... It's just going to make upper mids and treble more attenuated which will:
1) Decrease shoutiness, plasticness and any signs of overly bright tonality
2) Make soundstage more natural and compact (no artificially wide soundstage)
3) Forgot to add - it will sound more bassy subjectively
The most neutral config is with 2 rings while the most timbrally correct one is with 4 rings (my favourite). But it's still the same headphones, you are not going to mistake it with Sennheiser or Beyer of Hifiman or whatever. It's still K712 Pro, just tamed.