Another panel aging question...

[Jazzman53]

Speaker grill cloths have always been a controversial subject. In theory, if a cloth cover is part of the design then it should be baked into the voicing. But if someone removes the grill cloth and likes the sound better, it supports the theory that speakers always sound better without the grill cloth.

Your post about grill cloth reminded me of some measurements posted by Steve Bolser on the DIY Audio Forum on the effects of dust covers and grill cloth on ESLs. In the post linked below; the words "dust cover" refer to the thin Mylar membrane dust barrier that Quad ESL used on their ESL 57 and ESL 63 panels.

Here's the link to that DIY Audio Forum post: https://www.diyaudio.com/community/threads/all-acoustat-panels-can-give.282031/#post-4551994

Sometime after this post, [mathematician/aerospace engineer] Steve Bolser and [physicist] Dr. Rod White co-authored a technical paper on the effects of dust covers and grills on ESLs, including the effects of various absorptive materials used to dampen the diaphragm resonance on full-range ESLs. This paper modeled various configurations mathematically, and also measured the same configurations to validate the modeling.... a very scholarly work!

I'm kicking my senile self here because I can't remember where I read that technical paper or where to find it.

 

[Jazzman53]

Follow-up on that techical paper:
Title: Acoustic Transparency of Electrostatic Loudspeaker Assemblies

The paper is pretty extensive in scope, with information most useful to ESL designers, but also helpful for consumers in deciding on a speaker purchase.

Dr. White had sent me a preliminary copy of that paper before its publication in the AES (Audio Engineering Society) Journal. I lost that file when my old laptop smoked its hard drive, but I wouldn't be able to share anyway, since I don't own the rights to it.

However; if you click the link below and follow the instructions, you can request a copy from the authors:

https://www.researchgate.net/public...rency_of_Electrostatic_Loudspeaker_Assemblies


BTW; My DIY wire-stator ESLs have front and rear magnetic grills made from a sheer grill cloth purchased from Parts Express. I typically leave the grills on when listening, unless I want to show off the sexy stators.

I'm not hearing much of a difference with the grills on or off, but my high frequency hearing went away years ago so I suppose there could be an audible difference beyond my hearing range.

I had a buddy who owned refurbished Quad 57's, which had a lovely midrange sound but unimpressive highs, and I'm convinced that their non-porous film inner dust barrier took away what otherwise would have been pristine highs.

 

[Jazzman53]

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