Here is a trick to improve the sounds of the sub-woofer, nothing new though, I didn’t invent it but tried it today and it really tightened up the bass and (hopefully) results in less disturbances for my neighbors below me.
Basically you want to separate the sub-woofer from the floor, but still provide a very stable foundation. To do this, I bought a concrete slap, like this (one side is polished, which I put facing up). The width/depth is similar to the sub-woofer, and its 7 cm thick and weight:almost 30 kg (which is about 3 inch thick and 65 pounds):
So to sum it up, from bottom to top you will have heavy duty dampeners, concrete slab and sub-woofer. Don’t put extra dampeners between the concrete slab and sub-woofer though, that defeats the purpose.
Thats it, the floor next to the sub-woofer has no vibrations now, and the bass became tighter and faster (easily noticed in my case). The cost for this? Depends, but for me it was about $20.
This might even work for big full-range speakers, but I haven’t tested it.
Nice solution. I bought SVS feet for my sub (about $50US) which use an elastopolymer to accomplish the same. I live in an old house and my floorboards are like trampolines. They really made a huge difference in bass tightness and killed the floor resonances which were really, really boomy.
I tried some subwoofer feet earlier, but while they helped dampen the vibrations I felt the slowed down the sub a little (i.e. less tight). I get a somewhat similar result if I place the sub on a thick mat. That’s why I tried this solution. I haven’t tried the SVS feet though.
The sub will make the slab vibrate, even though its heavy and extremely solid. So I think the reason for why this solution works is that a lot of energy is spent on vibrating the stone slab, so the sub itself will vibrate less, and the dampeners prevent the vibrations to go into the floor.
The main reason I like this solution is that the bass really tightened up (no A/B required, it was immediately obvious), but I am unsure if this is because the sub vibrates less or the floor vibrates less.