lowering air vent noise?

[Wireneck]

I just moved into a new home. The room im recording in, has 3 air vents that supply air into the room. When the air cuts on, the air is alot louder/noisy than my previous home i lived in. Is there anything i can do to minimize the level of noise without doing anything major (its a rental home). Cutting off the air when recording isn't really an option at the moment since im in south georgia and its blistering hot this time of year.

[John Sayers]

If you are renting all you can do is build some extensions for the ducts that are lined with soundproofing insulation to cut down the noise. If you make the new extension ducts larger than the existing duct it will also slow the air down, thus reducing the noise also.

cheers
john

[Wireneck]

anyone have a pic or diagram of this? Is it just a box built around the duct with some sound insulation?

[John Sayers]

Is it just a box built around the duct with some sound insulation?

yup - that's basically it

cheers
john