A pair of speakers followed me home from a pawnshop last weekend. I won't go into details just yet because this post is only about the unusual way they are stuffed.
I've never encountered speakers with blocks of open-cell foam loosely installed. Is this a thing?
This is just what's found in the midrange/tweeter enclosure. I don't know the nature of the bass section as I would have to disassemble it more than I'm willing to during the first week ;-)
I've never encountered speakers with blocks of open-cell foam loosely installed. Is this a thing?
This is just what's found in the midrange/tweeter enclosure. I don't know the nature of the bass section as I would have to disassemble it more than I'm willing to during the first week ;-)
Open cell foam could become pricey in large quantities but diced offcuts may have been available. They may also be easier to fit around braces that call for complex cuts.
That could be the reason. There's a rear PVC port tube, rear tweeter & a couple tension rods passing thru the space.
Cost probably wasn't a factor in this case.
Cost probably wasn't a factor in this case.
I'm not sure I would trust that a chunk wouldn't find it's way into the speaker basket, or port.
Foam doesn't last forever, either. Does it's absorption & diffraction abilities change as it ages and breaks down?
Foam doesn't last forever, either. Does it's absorption & diffraction abilities change as it ages and breaks down?
Definitely not any foam I've used, so guess I should always prefix with a note to either loosely cover any components with cheesecloth or similar or make a bag using it to hold it same as we did back in the bad ol' fiberglass days.
Yes and why for best longevity need to use fiberglass insulation designed for heat/AC system ducting such as OC703.
I've always used polyfill or lambswool, with plastic mesh to keep it away from the basket.
I see that eggcrate foam is popular but I don't trust it--I've seen how fast it degrades.
But hey--i know relatively little and these were built by a pro.
I see that eggcrate foam is popular but I don't trust it--I've seen how fast it degrades.
But hey--i know relatively little and these were built by a pro.
Only thing I know about polyfil other than here is that with age it clumps real bad in my cheap 'throw' pillows and lambswool an expensive alternate to FG. 🙁 No experience with egg crate foam other than I've worked on speakers that had an undulating overly long pad loosely installed, so no way to quell its driver/sidewall's eigenmodes. 🙁
Since it’s a pawnshop special, I wonder if the foam was put in there by a previous owner? It doesn’t look like something a manufacturer would do. Maybe they belonged to that pillow guy?
I’m not a fan of foam damping; fiberglass, rockwool, and real wool are much more effective at damping.
I’m not a fan of foam damping; fiberglass, rockwool, and real wool are much more effective at damping.
These aren't from a traditional manufacturer. They're Unity Audio. I bought em for 2 reasons: They were a bargain.
My sat/sub speakers I've enjoyed for 40 years are also UA so I knew I'd like these.
My sat/sub speakers I've enjoyed for 40 years are also UA so I knew I'd like these.
The only thing I can figure is the foam gave the designers the results they were looking for. Can you tell if it’s silica infused or heavier than the usual foam? It’s odd that it was cut up in bite sized pieces and just placed in the cabinet. Nothing to panic over but it sure is interesting.
Those familiar with Bob Grost designs say that a lot.
The cabinets are squeezed between slabs of granite (Fountainhead actually). The drivers have been doped with a ceramic coating. His crossover designs are sometimes unusual.
The performance of these is great, with palpable imaging. My one complaint is a bit of glare in the upper mid-range that make female vocals too forward and shouty.
My challenge is to try to tame that. My knowledge of speaker & room measurements is very basic. If I fail I'll just push them out the door...curiosity satisfied.