Noise reduction for speakers

[Andy]

I have 4 speakers in my apartment.

I would like to minimize the vibration transmitted to the floor.

Right now, they are sitting on towels.

Look for those "on the cheap" ideas. :-)

Andy

[Don Phillipson]

This transmitted vibration suggests the speaker cones are causing the speaker case to vibrate. This suggests poor design of the speaker case (wasting energy that ought to have been output through the speakers) but you may not wish to rehouse the speakers -- just to reduce contact between the cases and the floor. The cheapest way to do this is to hang them on wires from the ceiling.

[jamesgangnc]

You could try some foam squares. It would help if you raise the speakers on stands. Part of the sound transfer will be to the floor in front of the speaker and raising it will reduce that. Don't expect much improvement though. Is the room carpeted? The biggest improvement will be from turning down the volume.

You actually want the speaker to be as rigid as possible for good sound quality. If the speaker is free to vibrate it muddies the bass.

[Home Guy]

You either have to mount the speakers to heavy base (that you would have to make yourself, likely out of concrete or stone) or suspend the speakers from the ceiling so they have no contact with the floor at all.

I've seen custom-made speakers integrated into 100 pound blocks used as the mounting base. The blocks were made from cement mixed with lead beads.

I've never seen speakers suspended from the ceiling (so that they're almost touching the floor) but if you want to isolate the speakers from the floor - that's what you'd have to do. Use stainless-steel aircraft cable for that modern look.

[clare]

Buy those interlocking foam floor tile kits - usually can get 4 2x2 foot for about 10 bux. Cut to speaker size - stack 2 or 3 deep.

[clare]

I was going to recommend, somewhat tongue in cheek, that he build a bigger box and pour concrete in the space between the speeker and the box.

[Jeff Thies]

Not a bad start.

You could suspend them.

Or continue with your idea. A sandwich: Low density, high density, low density, high density, low density...

The low density is what is stopping conductance of the bass. The high density is what is holding it together. Lost of ways to go about that. Low density could be air (use spacers or threaded rod/nuts), foam, corrugated cardboard. High density could be plyood.

Jeff

[Jeff Thies]

Try 4 rolls of TP, one under each speaker corner.

Note to others, We are trying to stop conductance of lows, dense materials will stop highs, but that is *not* the problem here.

Jeff

[Tony Miklos]

Set them on heavy duty bubble wrap.

[Home Guy]

Even if you suspend the speakers from the ceiling, the low frequencies coming from the speakers will still couple with the room acoustics and your floor and walls will still probably vibrate almost as much as if the speakers were in contact with the floor.

Does your speaker setup include a dedicated sub-woofer, or do you have large, full-range speakers such that you don't need a sub-woofer?

I personally feel that any sound system with a sub-woofer is sub-standard compared to having 2 or 4 large, full-range speakers. The use of sub-woofers will almost certainly not accurately reproduce the sonic content in recorded material - you will get an over-emphasis (to the point of distortion) of the low frequency content.

Your goal may not be to obtain accurate sound reproduction, but instead to impress your friends by having a sound system that rattles their internal organs. I don't know.

[Jon Danniken]

Well they do sell isolation cones (spikes) for just this purpose, but like many things audio they are a lot more expensive than they are worth (especially if you buy the ones with oxygen free metal).

For on the cheap, though, maybe make your own with some bolts and nuts?

Jon

[Jeff Thies]

You are a bright guy, but I don't know how much experience you have with designing speakers and rooms.

The problem at hand is keeping bass from coupling into the concrete of the apartment structure.

A speaker is a resonant box, whether it is sealed or ported. That resonance is designed in to extend the bottom end. This is all calculated. You make the box as stiff as possible, but there are reasonable limits (there are sand filled double wall boxes, which is really off the chart). As a result the box will vibrate, and you don't want to conduct that into the floor or everyone in the apartment building will hear that low end rumbling.

The sound coming from the speaker itself will be best contained by having dense room walls, there is little that can be done for that now. Some bass will couple into the floor regardless, but this is much weaker transmission path.

Bass has limited directionality, the more so the lower you go. It's a factor of the wavelength. That is why you can do dedicated sub woofers. The sound origin does not have to be close as it does for higher frequencies. Whether people crank up the sub too much is a different matter. They do.

As far as speaker size, larger diameter speakers develop the sound much further out. That is why large speakers in cars can be heard from so far away, but are not that overbearing in the car. Somewhat related to why bands can never get the bass player to turn down!

Jeff

I've run live sound, built monster touring sound systems, worked as an engineer in radio, designed high end car audio. Not the most experienced, but I have a background... currently just a programmer and out of the biz.

[The Daring Dufas]

Don't know the cost of their stuff but you might call them for expert advice:

TDD

[The Daring Dufas]

Invite friends over, let them lay on the floor put the speakers on their backs and tell them it's a free massage. :-)

TDD

[Sjouke Burry]

I would do a little experiment first. Send a friend to the apartment below,with a phone. Then pick up the speaker(s) off the floor, and check by phone if that makes any difference.Repeat until sure of the outcome. If no reduction, isolation from the floor wont do anything. But if it works well,get a nice 2 inch slab of stiff foamrubber, and put that under the speaker.

[Home Guy]

Are we talking about having the luxury of designing and building a room specificially for A/V use, or are we talking about making do with what-ever room we have?

Correct me if I'm wrong, but this thread did not seem to be about "designing speakers and rooms", so I did not say anything on that topic.

Um, where exactly did the OP (Andy) say that? As far as I can see, he's made only one post in this thread, and did not give details about the room's construction.

I'm operating under the assumtion of a single-family dwelling, with wood-stud / drywall construction.

Did I say anything to the contrary?

I said that attaching the speakers to a heavy, massive base would reduce the speaker's ability to transfer low-frequencies into the floor, and I said that suspending the speakers from the ceiling would do it as well.

[Jeff Thies]

No.

or are we talking about making do with

Right in the first line of the OPs post. Apartment. My assumption is concrete, because this is a common apartment construction and is a common problem with that.

My girlfriend has lived in more than one of those, and I've beat on the door (usually several apartments away) and dealt with this. Having a big white guy pounding on your door at 1 AM leaves an impression, no matter who you are!

No.

There is probably not enough dampening there, isolation is preferable, and practical. I still think 4 rolls of TP is the best and cheapest solution.

and I

Jeff

[Evan]

Headphones...

All of the vibrations will be directly transmitted to your head, bypassing the floor...

Your neighbors will be grateful...

If you have to ask how to reduce vibrations from speakers within an apartment you have too much speaker for too little apartment...

~~ Evan

[Don Phillipson]

This suggests a non-standard physics. The basic complaint is that the floor vibrates, and we know the speaker cases are in direct contact with the floor. HG now suggests that if the cases were separated from the floor by a foot or two of (compressible) air the "floor and walls will still probably vibrate almost as much." We should be interested to learn how this could possibly occur.

[aemeijers]

Or hit the dumpster behind the appliance store- those 2-inch slabs of closed-cell foam (NOT the molded styro things) used to pack high-end heavy electronics, make great vibration dampers. They are designed to protect expensive stuff in the box, as the semi bounces over chuckholes. Stack up a bunch of squares cut from those. I'm currently accumulating a stack at work from an ongoing project, but haven't figured out how to painlessly get them home yet. Great for carving equipment case liners out of, and they don't rot away into black crud like the fancy foam kits do.