I'm curious about recommended alternatives to wool felt damping for a center channel.
Locally, there is a suppier of 1/2" thick F-13 wool felt, but the minimum order is for several yards at $150/yard, so I'm researching alternatives. Here's what I've located, but I'm not sure how the various materials compare and which would satisfy the needs of the enclosure:
Locally, there is a suppier of 1/2" thick F-13 wool felt, but the minimum order is for several yards at $150/yard, so I'm researching alternatives. Here's what I've located, but I'm not sure how the various materials compare and which would satisfy the needs of the enclosure:
- 1/2" F-26 wool Felt - very reasonable at $28.50 for 12"x72"
- 1/2" F-15 wool Felt - $50.50 for 12x72"
- 1/2" felt rug pad - $42.36 for 12"x72' (includes shipping) 100% recycled felt made from new unused carpet fibers and yarn
- 9mm recycled PET Felt - $35 per 24"x24"
- 1/2" 60% recycled polyester panel - $65 for 24"x48' (includes shipping) spec sheet/product data
- perhaps this is an option to cover the wall behind my TV?
Used to use Orca Black Hole on the interior enclosure surfaces, now use GR Research No-Rez. The acoustic absorption of the foam (that your felt would be doing) with the added benefit of the mass loading and lossy membrane attached to the enclosure walls.
Have always used Acousta-Stuff for the interior fill, as needed. And yes, if you get some Acousta-Stuff under a microscope, it does have a lot more crimps on the fibres. This will facilitate more tiny movements of the fibres, absorbing energy (turning into heat), and reducing the speed of the acoustic wavefront. It does work better than generic poly-fill.
Dan
Have always used Acousta-Stuff for the interior fill, as needed. And yes, if you get some Acousta-Stuff under a microscope, it does have a lot more crimps on the fibres. This will facilitate more tiny movements of the fibres, absorbing energy (turning into heat), and reducing the speed of the acoustic wavefront. It does work better than generic poly-fill.
Dan
I use 10mm thick felt sheets (easy to find here) to line speakers, but for filling i use polyfill (pulled loose). It works, it's cheap and reliable/durable.
Since GM hasn't mentioned it yet 😉 -1in OC-703 rigid fibreglass board, or any equivalent brand rigid fibreglass board at the same thickness & 3lbs ft^3 density rating is getting on for 'as good as it gets' for most sealed, vented damping requirements, assuming the enclosure is well proportioned with optimised driver, vent positions as relevant, or you're not building an aperiodic box or aiming for a 'virtual volume increase' per Nousiane above.
SAE-F10 soft wool felt in my experience has roughly equivalent behaviour to OC-703 for a given thickness, albeit at a price. Ultratouch recycled denim, again in equivalent thickness, wasn't far off either & has the environmentally friendly card up its sleeve, which is no bad thing in this day & age, but unfortunately the most effective variation (which I think was a Bob Reimer commission) has been NLA for many years. The other 'standard' types are still good though -you just sometimes need to double up areas depending on the load in question, which since it's quite affordable in many regions isn't going to qualify for tragedy of the month. 😉
Whisper it: 30mm BAF is more effective than often believed, although again, you sometimes need to double up (or more) the layers. Since in relative terms it costs peanuts, again, not a huge deal. I prefer the others, but it's a viable alternative & much better than nothing at all, or egg-crate foam, most of which has the damping properties of cheese.
SAE-F10 soft wool felt in my experience has roughly equivalent behaviour to OC-703 for a given thickness, albeit at a price. Ultratouch recycled denim, again in equivalent thickness, wasn't far off either & has the environmentally friendly card up its sleeve, which is no bad thing in this day & age, but unfortunately the most effective variation (which I think was a Bob Reimer commission) has been NLA for many years. The other 'standard' types are still good though -you just sometimes need to double up areas depending on the load in question, which since it's quite affordable in many regions isn't going to qualify for tragedy of the month. 😉
Whisper it: 30mm BAF is more effective than often believed, although again, you sometimes need to double up (or more) the layers. Since in relative terms it costs peanuts, again, not a huge deal. I prefer the others, but it's a viable alternative & much better than nothing at all, or egg-crate foam, most of which has the damping properties of cheese.
+1 and let's not forget Bozak's Concert Grand's suspended Kimsul blanket that Altec liked enough to add it to one of their DIY pamphlets, though took them ~30 yrs to do it.
I'm a big fan of wool for use in loudspeakers. My T-lines are lined with 1/2" wool felt for the first 1/3 of the way. They are lightly stuffed with fiberglass in the upper chamber. My Econowaves are damped with 2" thick 100% fiberglass and the midrange is great from a 12" speaker. Much better than I expected. I don't like fiberfill or pillow stuffing or foam, I'm pretty sure they do mostly nothing. I've used wool blankets from Goodwill as damping too, they are inexpensive and work well but can give inconsistent results.
Some of the recycled felt may give you inconsistent results because it's made of whatever shows up at the factory. 😕
I like the felt tiles. They might be great on the walls in a studio or stuck on a woofer frame, or around a tweeter or even on the back panel of a speaker enclosure to remove resonances between the wall and high frequency diffraction. I glued some industrial floor tiles around my tweeters, it actually worked.
Some of the recycled felt may give you inconsistent results because it's made of whatever shows up at the factory. 😕
I like the felt tiles. They might be great on the walls in a studio or stuck on a woofer frame, or around a tweeter or even on the back panel of a speaker enclosure to remove resonances between the wall and high frequency diffraction. I glued some industrial floor tiles around my tweeters, it actually worked.
I like acoustic melamine with some poly stuffing in the air gap. This way no fibers can make their way to the driver and the melamine works best with some spacing off the wall.
My Bozak 302a's have the suspended curtain, but it's not Kimusl. Possibly fiberglass?+1 and let's not forget Bozak's Concert Grand's suspended Kimsul blanket that Altec liked enough to add it to one of their DIY pamphlets, though took them ~30 yrs to do it.
I settled on 100% recycled wool from Jule Fidelity for the center channel.
Thanks for all of the input.