What's the best way to insulate heat ducts?

Webguy64

Hi,

I'm currently finishing my basement and I'd like to insulate the duct work to keep sound from the basement home theater from traveling throughout the house. Is there an effective way to do this without spending a bundle? I'm using an acoustic drop ceiling with unfaced R19 above. I know some sound will go into the ducts thru the heat registers and cold air returns, but would insulating the ductwork separately help?

I've seen duct insulation at Home Depot.com but I'm not sure if it's just a gimmick. Thanks!

MechanicalDVR

Duct wrap on the outside of the duct won't do anything for what you want. The ducts would have to be lined to make a difference with sound antenuation. Are there going to be returns near your speakers? Adding a length of flex duct between a stackhead and the sheetmetal ducting will cut down on transmitted noise.

Webguy64

Thanks for the tip. The duct is in the center of the room, the speakers won't be too close, but at 'theater volumes' I'm sure the sound will travel thru them. I won't waste my time (and money!) wrapping the ducts. Maybe I'll try the flex duct...

The other thing I was thinking of is using magnetic sheets of paper with acoustic tiling glued to them. I could then stick them on the heat ducts & cold air returns to keep the sound in the basement. Should help at least a bit...