Spikes versus Rubber on wood floor?

There are many threads on Audiogon and AA about suspended hardwood floors.

I tried many solutions on my suspended hardwood floor and the only thing that worked was to decouple the speaker from the floor. Coupling the speaker to my suspended hardwood floor was a disaster. All coupling does to many suspended floors is excite the floor which creates a delay in the sound traveling in the floor and it muddies the bass badly.

You will find in the many threads here and on AA that the vast majority of suspended floor owners had much better success with decoupling. I know...I searched every thread available and the over-whelming consensus was coupling was bad, decoupling worked. All of the theories you will hear are great, but there is nothing like actual experience. Search "suspended hardwood floor" and "suspended floor" here and especially on AA and you will find a lot of "actual experience" from owners with suspended hardwood floors, not a bunch of theories. That is not to say that coupling may not work on "any" suspended floor, but the preponderance of evidence from owners is that coupling is not good.

And as far as movement of a speaker goes, there are also those here or on AA who have suspended their speakers from the ceiling with absolutely no movement of the speaker when playing...none, zilch. Once again, theories are nice, but actual experience is soooo much better.

Fiddler, if this is what's happening in your case:

"All coupling does to many suspended floors is excite the floor which creates a delay in the sound traveling in the floor and it muddies the bass badly."

Then it's because the wood floor is flexing (what you call "excite") underneath the speaker allowing the woofer motion to rock the enclosure back and forth. Remember, it only takes 1/16" of deformation (flex) in the floor for a 5 foot tall speaker to rock back and forth as much as 3" at the top! There are three possible solutions:

1.) (the easiest) reposition the speaker so the front and rear spikes/cones/feet are on top of, or very close to, the (two closest) joists themselves (as discussed earlier)

2.) If (1.) isn't possible for some reason, then put blocking (little cross joists) between the two joists right under the speakers and/or put posts (or jacks) from the ground to under the floor where the speakers sit.

3.) If (1) and (2) aren't possible, the best solution (a bit of a hassle to do nicely, but works great!) is to run a brace (aluminum tube or plastic PVC pipe works well) from the top-back of the speaker to either the wall behind, or back down to the floor at least 4 feet behind the speaker, and secure it.

Any of these solutions will keep those woofers from rocking the cabinet instead of your ears. An additional benefit will be better highs and mid-range transients.

Hanging speakers can work also, except the chains or cables need to be splayed enough to insure that the speakers don't sway even a little. That's sort of an ugly tour-de-force don't you think?

Nsgarch, thanks for the feedback, but number 1, 2 & 3 won't work simply because the floor is being excited by certain frequencies. The problem is not floor flex, per se. The floor is acting like a drum head. It doesn't much matter where you strike the drum head, it will still resonate. Until the frequency vibrations are sinked to something with a much lower resonant frequency (such as, the ground or a concrete pad on the ground), they just rumble around until they dissipate. So moving the speakers over joists won't make a big difference. Believe me, I tried.

Stiffening the floor would cure the problem, but most effectively if it is stiffened by applying pressure from the floor to the ground, i.e. using floor jacks and posts or footings and pilings. These solutions simply change the resonant frequencies and the problem can be eliminated. But the simpler solution is to decouple the speakers. Do a search for actual results.

And according to other users, hanging a speaker from a single chain does not produce any movement of the speaker when the speaker is playing. I personally have no experience with this, but that is what has been reported from actual use.

Wellfed,

Now you've gone and done it, the Big Fat Dots are relatively inexpensive, so I suppose I am going to have to break down and try them. Still curious, how does the hardness compare with a hockey puck? Thanks, Tim

Fiddler, apparently you have a very under-engineered floor which is indeed being "excited" by the sound waves in the air! Is it an old structure? I have cured this problem for clients (I'm an architect) who had intolerably bouncy floors due to undersized joists put in by a shady builder (joists can be "up to code" to carry the load, but they usually need to be bigger than that to resist bending)

My solution in such cases (when none other was possible or practical) was to add a couple more layers of plywood subfloor, with the sheets staggered and edge and face nailed very well. This acts like a stressed skin and keeps the floor from bouncing excessively.

Frankly, I don't believe attaching the speakers elsewhere (like the ceiling) will keep the sound waves in the air from exciting the floor, as it is right now.