Flex Duct or Rigid metal duct

[RickH]

There is a lot more then adding drywall and insulation to get a soundproof room. Addressing the HVAC system will do no good if the walls aren't properly constructed. I would suggest getting Rod's book "Build it like a pro". This will give you a good understanding what is involved to properly isolate a room.

Good Luck!

[Rockenberry]

Originally Posted by RickH

There is a lot more then adding drywall and insulation to get a soundproof room. Addressing the HVAC system will do no good if the walls aren't properly constructed. I would suggest getting Rod's book "Build it like a pro". This will give you a good understanding what is involved to properly isolate a room.

Good Luck!

+1

[Richie]

Fiberglass lined metal duct is best. The lining is on the inside of the duct with OC 703 top coated with shellac to keep the fibers in place. Flex ducting is a good alternative, easier to route and hang, but prone to kinks which can cause whistling noise. To eliminate turbulence, have your duct increase in size as you get further from the HVAC unit, the opposite of how it is usually done in most applications. This lowers the velocity of the air but keeps the volume air moved unchanged. Flex duct is less expensive and will work fine if you are careful and follow the rule of thumb above.