DIY Speaker material recommendations

We have several build and recommendation threads for projects, but I'd like to have a thread where materials can be discussed and collected.

I remember seeing some discussion about enclosure stuffing, but my search terms aren't bringing up anything that is familiar. I have been using some ancient pillow stuffing that may have shortened my life by handling since I am cheap and didn't want to buy any Acoustastuf. I am doing some new builds and thought of getting some proper materials to both line the cabinets with and to stuff them with.

Is Acoustastuf worth it if my total project costs rarely go over $250? Also, what about lining enclosures? I see some Sonic Barrier stuff at Parts Express that I was going to go with, but I have seen all sorts of things recommended like various rug pads, insulation, recycled jeans, mattress foam, etc. I need relatively thin linings since I build mostly micro/bookshelf level stuff (Overnight Sensations). Any thoughts or recommendations? Thanks!

 

For stuffing: anything with good density will work - .5 to .75lbs/cuft is good. Problem is, most stuffing you're going to get a Jo-Ann isn't very dense, and you'll probably need to stuff a shit load into the enclosure to get proper density. Stuffing a ton of cheap pillow stuffing evenly can get to be a pain in smaller cabinets, especially if there's any bracing in the cabinet.

For reducing internal reflections within the cabinet: look for open-cell polyurethane foam; doesn't matter if it's from a mattress topper or sheet foam from an industrial supply house like McMaster. But it ought to be open-cell, not closed-cell foam. If you're okay with handling itchy fiberglass, any 2" thick faceless fiberglass insulation will work.

For damping cabinet resonances: constrained layer damping usually works best (different density/mechanical Q sheet materials bonded together with viscoelastic glue), so its a balance between the frequencies you're trying to attenuate, and how much volume you're willing to lose to do so within the cabinet. For cheap and cheerful you can try sheets of vinyl flooring, stone tiles and construction adhesive, etc. I would expect that for micro/bookshelf speakers, your panel resonances are in the 100 - 400 hz range. Try playing sine sweeps through the bass/midrange with your ear pressed to the cabinet to hear what frequencies excite the cabinet.

So, an inexpensive cabinet treatment could look like this:

cabinet wall -- vinyl/laminate flooring -- construction adhesive -- stone/concrete tile -- construction adhesive -- fiberglass insulation -- acoustastuff

Edit: I'd add, too, that good cabinet treatment is more important in larger cabinets, especially if they aren't well braced. Back when I was into speaker building my favorite stuff was No Rez from GR-Research, plus plain old polyfil for stuffing. No Rez is kinda pricy, but a little goes a long way (you don't necessarily need to cover the interior of the enclosure wall-to-wall), and you can reuse it if you're careful when removing it from an old cabinet. Hit the adhesive side with some spray adhesive and it'll stay put in a new cabinet.

 

For my recent FE108EZ project, I used F-13 felt from this outfit called Zoro that sells on eBay (https://www.ebay.com/itm/2FKB2-Felt...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649) for damping the inside of the enclosure. A cheaper alternative by price per unit would have been UltraTouch denim insulation from Home Depot or the like.

 

Thanks guys, I have some of the UltraTouch and some Acoustastuf on order.

What about wiring? Do you just use speaker wire? That is something I don't quite get. Most internal wiring for amps is relatively tiny compared the the gauge used for runs to the speaker. Can I use hookup wire internally (22awg)? We are talking fairly low powered speakers at the moment, so it will probably not matter, but just curious incase I do go bigger down the line.

 

When it comes to wiring what matters is total resistance, and resistance is proportional to length and inversely related to wire gauge.

Speaker cable needs to be a large gauge because it's a longer length than the distance from the crossover to the drivers.

Also in a lot of crossovers there is a resistor in series with the driver. Taking into account the resistance of the wire and lowering the resistor value can be equivalent to using calculated resistance and a 'zero-ohm' wire.

I missed where you talked about amp wiring. Most parts are low current so larger wire isn't necessary. Only at the output transistors or the secondary windings of the output transformer do you deal with higher currents. Plus the wire is solid core instead of multi-filament wire, which usually has a higher current rating for the size.

 

For internal speaker wire from crossover to drivers I've been happy the VhAudio unshielded twisted pair. Relatively cheap and pretty much completely overkill. Very high quality copper. But pretty much anything OFC twisted pair, and greater than 16ga is plenty good. If you're feeling tweaky, maybe try some dueland tin plated copper 20ga (tweeter) or 16ga (woofer). still relatively inexpensive and sounds great; better than the VHAudio stuff, imho.

 

For internal sound absorption on my last project I used 1/2" soft wool felt on clearance from this site and it worked great. It was the recommended material by the designer of the speakers I built. A little pricey but they seem to always have odd widths on sale.

 

obligatory Troels link

http://www.troelsgravesen.dk/cabinet-damping.htm

 

Got some recycled denim insulation (link) and some Acoustastuf. Going to redo my OSMTs and some 3" based speakers with this stuff to see how much it changes. Thanks for the recommendations.