I used a liberal amount of ERS fabric, and I didn't notice a diminishment of high frequencies. That could be because of where I placed it, or if your hypothesis is correct, it could be because it merely removed some high frequency hiss.
I agree with your observation that some audiophiles perceive high frequency hiss as "air" or ambience. Personally, I tend to perceive it as noise.
In fact, with the ERS fabric installed, I can say that there is simultaneously LESS hiss and MORE ambience.
bc
I agree with your observation that some audiophiles perceive high frequency hiss as "air" or ambience. Personally, I tend to perceive it as noise.
In fact, with the ERS fabric installed, I can say that there is simultaneously LESS hiss and MORE ambience.
bc