I am prepping my basement for doing some recording. My first step is to reduce noise going through the house. I'm thinking about replacing all my HVAC 6" and 5" diameter rigid tubular duct work with flex duct. I would only do this in the exposed areas in my basement from my furnace leading to the up to the first floor access. Thoughts?
HVAC modifications
- Thread starter 56BelAir
- Start date
Are you trying to reduce the connected vibration noise of the metal? That might work as flex would seem likely to decouple that sort of vibration. It's actually more turbulent as far as the air flow, but I'd be surprised if you'd hear that at low flow speeds. But we're winging it here. (I'm assuming it's insulated flex not the bare plastic or aluminum?
Chili
Site Moderator
One thought comes to mind and I'm not sure if it's a real issue. If you are switching from rigid to flex duct, then you need to seriously upsize the diameter. The inner diameter of the flex duct is smaller than the same size rigid duct and it is more resistant to airflow due to the spiral wire inside. A quick google search supports this notion.
In the first studio I ever built, I used 6" flex duct for supply and return air and I did not get enough airflow; even with an inline booster fan. That studio was always hot.
hth
In the first studio I ever built, I used 6" flex duct for supply and return air and I did not get enough airflow; even with an inline booster fan. That studio was always hot.
hth
Bobbsy
Boring Old Git
Watching the acoustic consultants work out HVAC needs for professional studios, it seems they are considering two separate issues: the background sound of the moving air supplying the studio and conducted noise travelling into the studio via the ductwork.
Their solution for the moving air is "large ducts and slow movement". I've seen them use ducts four or five feed by two or three feet in size. They also fit special grills with large, angled gaps to avoid the typical hissing noise.
Their solution to the conducted noise is to use short lengths of flexible ducts to de-couple the duct work inside the studio from the outside world. There were also special baffles inside the ducts so there was no direct route from outside to in--any sounds would have to go around a series of "hairpin bends" with absorbent material on each baffle.
Obviously you couldn't do all this in a typical home studio but I mention the above in case anyone more clever than me can come of with any bodges to achieve similar effects.
Their solution for the moving air is "large ducts and slow movement". I've seen them use ducts four or five feed by two or three feet in size. They also fit special grills with large, angled gaps to avoid the typical hissing noise.
Their solution to the conducted noise is to use short lengths of flexible ducts to de-couple the duct work inside the studio from the outside world. There were also special baffles inside the ducts so there was no direct route from outside to in--any sounds would have to go around a series of "hairpin bends" with absorbent material on each baffle.
Obviously you couldn't do all this in a typical home studio but I mention the above in case anyone more clever than me can come of with any bodges to achieve similar effects.
