Re: Harbeth Monitor 40.1 specific
As I explained, every textbook on acoustics this past hundred years or so correlates the thickness, area, compliance, density and absorption coefficient (quality) of treatment with sonic absorption. If a product becomes available for room damping in this universe which ignores thickness, size and softness and is proven to do the job of expensive, heavy conventional treatments then basic physics will have to be re-written and acousticians thoroughly and expensively re-trained.
Alan A. Shaw
Harbeth Audio UK