Author Topic: DIY damping on poster mounts  (Read 626 times)

Offline JonnyP

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DIY damping on poster mounts
« on: September 23, 2016, 06:46:06 PM »
OK, my sound at home is great and all the rugs etc do a good job of 'no echo' but as I have a number of block mounted posters and a couple that I want to DIY, I figured filling the backs with some damping material a. Couldn't harm and b. May actually further improve sound.  Any material that people would suggest? Cheap and easy to find would be preferable as an initial experiment
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Offline ScottulusMaximus

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Re: DIY damping on poster mounts
« Reply #1 on: September 24, 2016, 09:23:46 AM »
"Batting" from a material shop, is the stuff from the inside of duvets. Cheap as chips and nothing funky in it so just cut to size with scissors and contact glue or staple to the inside of the frame.

All my block mounted stuff has this stuff in it. No idea if it makes any difference though.
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Offline Curlycat

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Re: DIY damping on poster mounts
« Reply #2 on: September 24, 2016, 10:35:28 AM »

Offline chrisc

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Re: DIY damping on poster mounts
« Reply #3 on: September 24, 2016, 10:42:36 AM »
Charity shop towels, who would have thought?  A big plus is that you can get some superbly decorative towels as the visible layer.  Certainly inexpensive though

Offline Curlycat

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Re: DIY damping on poster mounts
« Reply #4 on: September 24, 2016, 10:55:57 AM »
"Batting" from a material shop, is the stuff from the inside of duvets. Cheap as chips and nothing funky in it so just cut to size with scissors and contact glue or staple to the inside of the frame.

All my block mounted stuff has this stuff in it. No idea if it makes any difference though.

Ditto - I have seen people using carpet underlay for damping. Personally I would not like using it. I have seen underfelt with shards of metal in it. Not sure how that can effect Murphy's law when placing near an expensive driver. I'd rather just avoid it. Doggy blanket seems to be a "safer" option, but before I use it, I give it a good once over.

Offline Timber_MG

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Re: DIY damping on poster mounts
« Reply #5 on: September 24, 2016, 10:57:10 AM »
Thanks Felix, interesting video.

Air flow resistivity is the material property one is after in sound absorption (geometry does the rest mostly) and foam is not really a good material for a typical wide-band absorber.

Offline JonnyP

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Re: DIY damping on poster mounts
« Reply #6 on: September 24, 2016, 06:51:25 PM »
Thanks all, will try the towels idea with old T-shirts in the mix
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Offline pwatts

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Re: DIY damping on poster mounts
« Reply #7 on: September 25, 2016, 10:41:50 AM »
Having just begun delving into this with great fun (and having wanted to do the same thing) paint on canvases will have a non-negligible flow resistivity. Stuffing the back (assuming 30mm or so) with absorbent will create a narrow-band absorber that will not be effective below a few hundred Hz because of the limited depth, and not be effective above around 1kHz because of the reflection of the paint. The paint will greatly reduce the effectiveness of loose fluffy material; something denser will be better.
The porousness of the bare canvas, the amount of coverage (some paintings leave have lots of bare white canvas exposed) and the thickness of the paint of course all play a role.. thin watercolour paint will be different than a thick enamel.

Since the carpet should help at the higher frequencies, this could indeed help extend absorption to the midrange so is worth a shot with some cheap stuff lying around; if effective replace it with uthermo to improve absorption significantly above batting/isotherm/fibreglass.
« Last Edit: September 25, 2016, 10:51:34 AM by pwatts »