New Advent Grille cloth test results

[Carlspeak]

I have written here at CSP before about grille cloths and their structure and testing. Here is a link to an AR post on the subject

http://www.classicspeakerpages.net/IP.Boar...2&hl=grille

Recently I located a supply of very high quality 100% linen that matches the original New Large Advent very closely in color. It weighs a hefty 7.5 OSY and is 18 mesh vs the 16 mesh of the original. I feel the 18 mesh is just closed up enough to not require the hassle of including the black backing cloth and yet be acoustically transparent.

I ran a frequency response test with and without the fabric in front of a loudspeaker tweeter. That test was followed up with a control using an original NLA grille with original clothing. All three responses were virtually the same indicating the new grille cloth will make a good replacement.

The tests were conducted with the test mic located 24 inches away from the tweeter, on axis. I have found this test method to be very telling with my very sensitive ATB-Pro acoustic measurement software and ECM-8000 test mic.

There is an ASTM test method for sound transmission but it seems to be designed for office furniture acoustic panels and employs reflected sound. I am not aware of an ASTM method similar to mine.

Below are some tests done on fabrics - including the new Advent cloth. That test include a picture showing the original grille laying atop the new cloth.

Note the cotton muslin test results show a noticeable drop in response. This could be bad or good depending on whether or not the HF are bothersome and the speaker doesn't have an Lpad.

[dynaco_dan]

I have written here at CSP before about grille cloths and their structure and testing. Here is a link to an AR post on the subject

http://www.classicspeakerpages.net/IP.Boar...2&hl=grille

Recently I located a supply of very high quality 100% linen that matches the original New Large Advent very closely in color. It weighs a hefty 7.5 OSY and is 18 mesh vs the 16 mesh of the original. I feel the 18 mesh is just closed up enough to not require the hassle of including the black backing cloth and yet be acoustically transparent.

Hi Carl

Very nice job done, as usual.

[Carlspeak]

Here is a pic of a NLA and KLH 5 grille side by side. The basic fabric appears identical with the KLH grille somewhat darker. Both have the black scrim fabric backing.

I guess H. Kloss probably had something to do with the cloth selection on both.

[JKent]

Recently I located a supply of very high quality 100% linen that matches the original New Large Advent very closely in color. It weighs a hefty 7.5 OSY and is 18 mesh vs the 16 mesh of the original. I feel the 18 mesh is just closed up enough to not require the hassle of including the black backing cloth and yet be acoustically transparent.

Hi Carl

Where is this cloth available? I'm always on the lookout for suitable cloth for the KLH Model Eight.

Kent

[Carlspeak]

Hi Carl

Where is this cloth available? I'm always on the lookout for suitable cloth for the KLH Model Eight.

Kent

I'm not sure what the Model 8 cloth looks like so I can't vouch for any kind of match with that particular speaker's cloth. In any case, the cloth is available from yours truly.

[Fred Johnson]

Carl:

Is there any chance you still have some of this cloth? I need enough for four original large advents?

Edit: I now realize that Carl has a web site with his speaker repair services. No response needed from you, Carl.