We have a job where the floors are of a joisted construction, with dry lining / plaster board ceilings and below and plywood sub floors above.

We are putting in ceiling speakers into the ceilings and want to provide something to limit sound leakage to through the floor above.

The options im aware of are :

- acoustic fire hoods
- dynabox

Wondered if there was anything else on the market ?

Which speakers? Some brands offer optional back boxes or, you could install your own. Has the drywall been installed? How much sound leakage is acceptable?

Some good reading [Link: google.ca]

Dynabox is only helpful for high frequencies. So, for background music, prob good.

Mass-loaded vinyl may be a consideration for the floor above, above the subfloor, and below a carpet or laminated floor.

- Speakers : TBC
- Backboxes : Ive seen these for Sonance .. didnt know other do them
- Acceptable leakage : would like to stop 20 / 30 db

There's a system used in highrises that approach the problem from above. I once saw a floor under construction, or rather under improvement.

The floors were concrete. Some layers, maybe 1/2" total thickness, of a flexible plastic foam sheet were placed on the floor. Then there was about a half inch of standard floor underlayment, finished by 3/4" wood flooring.

I offer this because there IS an answer, though the cost of that may be more than you can spend for what you need. It kind of makes you ask yourself just how important it is, though. (I mean, this building... I watched for a couple of minutes one day while a crane lifted a grand piano to at least the 10th floor. They landed it on the patio and shoved it inside, then went to work reassembling the wall between the patio and the living room. Now THAT had a budget!)

considerations, in addition to speaker backboxes, include location of hot air or cold air returns, carpeting on floor above, construction methods, etc.

What ever sound comes out of the front of a speaker, a similar amplitude of sound comes out the back of the driver.

Start with a quality back box. We use Triad speakers, which come with a sealed enclosure. (some cheaper rounds do not, but obviously not the right product for a project like this)

You can add insulation above and around the speaker enclosure, or you can have them apply spray-foam insulation to the bottom of the sub-floor above the speaker.

No matter what you do, some sound will probably come through the floor when the system is turned up. Be sure and set those expectations. I have yet to find anything "soundproof" in a house.

I've used these in a few jobs recently. A whole house audio system and two surround systems with 5 in ceiling speakers. They have enclosures and are also ported out the front. Noticeably better misbass response than others I've used and less leakage of sound to the room above. I attribute this not only to the enclosure but likely also because of the ports allowing some of the energy to exit the enclosure from the front.

I am very pleased with the sound.

Craig.

Like Brad said control the back wave and set expectations. You could add as many sound reduction methods (layers of mass and isolation) to the back of the speaker box as you want but in the real world it won’t make any difference. Drywall ceilings are so you don’t have to look at the joists and mechanicals (think open basement) and the flooring above is for holding weight. There is zero consideration given to sound reduction in basic residential construction. A good back box will stop more sound from the back wave then the drywall will stop from the front wave, it doesn’t matter if the speakers are in the room or in the ceiling. If they are serious about reducing sound they have to use construction that focuses on that.

I think you left something out.

Maybe nothing(missing info) is what he meant. As nothing you can just mount a speaker into or behind it will solve the problem. So in those cases where solving it was the only acceptable solution he used nothing as he could not.

There is no such thing as sound proof, at least for WHA. Backboxes , dynamat and some rockwool is the best you’ll get. Still will hear some bleed through when turned up.