Question about ductwork

[elee532]

Cut the hole to install one of my CDT 5800 speakers and there was an air return duct butting up to the speaker. I was able to push it up just enough to get the speaker to fit. Is there any problem with having a duct run just over the speaker like this?  

[Peter P.]

There could be some vibration from the speaker inducted to the duct, causing it to vibrate. That may be heard at the other registers.

 

Crank up the volume on that one speaker if you can, then go listen at the other registers. If it's heard, you may not want occupants of the other rooms to hear the sound say, while they're sleeping.

 

If you hear nothing, you're good.

 

Also, if they're close enough and the speaker is playing loud, it may cause the duct to buzz or rattle. Crank it up to test.

 

At the absolute worst, cut the hole oversized and drop the speaker 1" for better clearance. In the whole scheme of things, you'll never notice.

[elee532]

Thanks @Peter P.! I wonder if I should have put a piece of insulation between the speaker and the duct? How hard is it to take one of these speakers down once it's been screwed in?

 

[babadono]

Give the back of the speaker as much clearance as possible into the attic volume. These are infinite baffle speakers. My $0.02.

[Peter P.]

15 hours ago, elee532 said:

Thanks @Peter P.! I wonder if I should have put a piece of insulation between the speaker and the duct? How hard is it to take one of these speakers down once it's been screwed in?

 

I don't know the answer to your question.

[Khornukopia]

On 12/9/2019 at 5:34 AM, elee532 said:

I wonder if I should have put a piece of insulation between the speaker and the duct? How hard is it to take one of these speakers down once it's been screwed in?

 

Better to have air space between the speaker and the duct. Something like a thin layer of Dyna-Mat on the ducting could be helpful to reduce unwanted vibrations. If you loosen the screws a few turns, the mounting ears should swing out of the way, allowing the speaker to drop out of the ceiling hole.