Rather than try a "band aid" that results in another set of completely different problems, why not go to the source ? If you are bothered by the bass talking to you via the floor, why not install some simple braces underneath it ? I don't see any problem with doing something like this, especially since you said it was a crawl-space and not a basement.
In order to do this and have it work properly, you will need several thick planks of wood and a few inexpensive "bottle jacks". Lay a plank down on the crawl-space floor, place a bottle jack underneath each speaker and then place another plank on top of the jacks. If you do this right, you'll not only make the floor more rigid / less susceptible to resonance, but you'll be transfering floor bounce to Earth ground via the bottle jacks.
You can take this a step further and install a few more jacks / planks where they are needed. While you or someone else is in the crawl-space, have someone walk around in that room. Where the floor makes the most noise, that's where the supports go. How many braces that you'll need will obviously depend on how sturdy the floor is.
Another less expensive alternative is to use 4 x 4 posts cut to length rather than leaving the bottle jacks in the crawl-space as the support. You may still need a jack to initially "lift" the flooring while wedging the supports in place, but you'll only need one jack to do this and you can put it to use somewhere else once you're done with it. I would suggest using a piece of wood both under and above the posts as sort of an "end cap". This will help to both level out the ground and spread the load out a bit. If you use a larger plank above the post, you may be able to contact several of the floor joists at once, which will help to make the floor more rigid. If possible, running one long plank across all of the floor joists between the speakers would work best. That is, if the speakers are running across the joists and not parallel with them.
The advantage to using the jacks is that you can adjust them as needed should the flooring, soil or house shift over time. If using posts, you may have to shim them or cut new posts. Finding just the right size shim that is both sturdy and easy to get into place might be a good trick and that's why the bottle jacks may be slightly easier ( albeit more expensive ) to work with in the long run.
While you are at it, you might want to think about breaking ground at your electrical box that houses your outlets and dropping a line straight through the floor down to a dedicated Earth ground rod. This would offer a phenomenally short and low resistance path to ground for you. Before doing so though, i would check with a local electrician to see how this could be done in order to maintain safety factors while still meeting local code. Sean
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In order to do this and have it work properly, you will need several thick planks of wood and a few inexpensive "bottle jacks". Lay a plank down on the crawl-space floor, place a bottle jack underneath each speaker and then place another plank on top of the jacks. If you do this right, you'll not only make the floor more rigid / less susceptible to resonance, but you'll be transfering floor bounce to Earth ground via the bottle jacks.
You can take this a step further and install a few more jacks / planks where they are needed. While you or someone else is in the crawl-space, have someone walk around in that room. Where the floor makes the most noise, that's where the supports go. How many braces that you'll need will obviously depend on how sturdy the floor is.
Another less expensive alternative is to use 4 x 4 posts cut to length rather than leaving the bottle jacks in the crawl-space as the support. You may still need a jack to initially "lift" the flooring while wedging the supports in place, but you'll only need one jack to do this and you can put it to use somewhere else once you're done with it. I would suggest using a piece of wood both under and above the posts as sort of an "end cap". This will help to both level out the ground and spread the load out a bit. If you use a larger plank above the post, you may be able to contact several of the floor joists at once, which will help to make the floor more rigid. If possible, running one long plank across all of the floor joists between the speakers would work best. That is, if the speakers are running across the joists and not parallel with them.
The advantage to using the jacks is that you can adjust them as needed should the flooring, soil or house shift over time. If using posts, you may have to shim them or cut new posts. Finding just the right size shim that is both sturdy and easy to get into place might be a good trick and that's why the bottle jacks may be slightly easier ( albeit more expensive ) to work with in the long run.
While you are at it, you might want to think about breaking ground at your electrical box that houses your outlets and dropping a line straight through the floor down to a dedicated Earth ground rod. This would offer a phenomenally short and low resistance path to ground for you. Before doing so though, i would check with a local electrician to see how this could be done in order to maintain safety factors while still meeting local code. Sean
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