These boxes work! My previous home had 5 ceiling speakers and we could hear the sound clearly in the upstairs bedroom. I've moved to a new location and installed 5 of the same speakers in the ceiling but came across these rubber/foam boxes online and they made a world of difference. There is a noticeable reduction in noise levels in the upstairs room, although we have wood floors upstairs (i.e. very little insulation) and I was very concerned about sound transmission. It's not completely silent, but it's significantly quieter than our previous setup (which even had the benefit of carpet). If you're doing a retrofit there aren't many options, but they seem to work great. They go well with 8-inch speakers, but this is by far the maximum size. I was also a little worried about the speakers getting warm on the inside, but in the speaker box that I have access to, I don't feel any heat on the outside surface. neither on the box nor on the front surface of the speaker. Yes they are a bit pricey but there is nothing else on the market. They were easy to install and make a difference. Just don't expect total silence.
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