Axiom Home Page Forums General Discussion Home Theater advice on HVAC silencing

Take everything below with a large grain of salt; here I'm going from distant memories, party conversations and things I read on the Internet, not hard experience :

I'm iffy on #1 -- going to a flexible duct normally means more noise being generated by the air flowing through the duct, since the inner surface is not as smooth as the plain duct.

There are two different noise sources at work here -- you want bends in the pipe to reduce noise from the HVAC equipment itself being conducted through the pipe to your vents, but you want smooth, slow airflow (big ducts) to minimize noise being generated in the ducts by the airflow. What is the primary source of HVAC noise right now ?

re #2 -- just curious why top and side rather than bottom and side, since your HT will be in the basement. Unless you are using something heavy and solid, aren't you primarily going to get sound reduction by interposing the insulation between duct and HT area ?

re #4 -- sounds good although I haven't actually seen anyone use isolating bars on the ceiling, just the walls. Is the intent here to control sound from the HT leaking up into the rest of the house ?