So I began experimenting and using this material to dampen the housing of my T50RP.
It hasn't got a brand though the shop who sold me this says it's automat, essentially used in cars to dampen vibrations and outside noise but this particular one is often used on the underside of the hood to reduce engine noise and lower engine temperature. I used it to dampen the housing of the T50RP. It's basically 9mm thick foam with an adhesive backing.
After many experiments and long term testing, this is the final (for now) configuration.
Automat cut in half and applied onto the entire ear side baffle with deleted stock felt exposing the driver.
The usual flushed plasticine in the baffle, a tiny square of medical tape covering the inner bass port, 3 layers of cotton pads stack onto each other, thick fiber wool covering the sides of the housing and automat dampening the whole housing. The vent is also covered with automat but I opened two vents which I found to have just the right quantity of bass without suffering from bloat.
And I also used Hifiman Pleather pads which fits surprisingly well but is a bit too stiff and hard. Since I'm wearing glasses, I don't get a full seal and the bass response drops noticeably. If I take off my glasses, the bass is weighty, impactful and a good amount of quantity. Mids aren't sacrificed and still maintains very good tonality and highs are sharp but it's all right for my ears though I wish it could be as smooth as the HE-500.
In total, the materials cost me around $15 (Pads not included since they're spares from my HE-500).
There are some improvements that I can make, for example the cotton pads can be changed with much thicker ones and the pads.
Speaking about pads, I'm thinking of ordering the Alpha Pads and I would like to know how are they like? Are they plushy enough so that I can wear my glasses while listening without losing bass response? Do they improve soundstage? What kind of impact in SQ and FR should I expect?
Edited by VortexBlast - 9/12/13 at 2:45pm