I realize I may be off the mark here but given this is the best forum around knowledge wise, I thought I would throw this question out. Yes, I'm a proud owner of the Bose L1 system, our band has 3 and I use mine for acoustic performances. Aside from that I have a home studio that was DIY from the first nail. The studio is 100'sq feet and does have a window/window unit and of course door entrance way. (external building behind my house)

Given the amount of insulation, sound proofing boards between the walls, floating floor, and acoustic absorbtion panels it seems I've built a large thermos. When recording vocals, I of course turn off all non essentials including the window unit and then cover the window with some foam panels I acquired. I use a 3 tier divider (bought at Hobby Lobby), lined it with a moving blanket, and then installed crate foam. When I form a u-shape with the 3-tier divider it creates a nice isolation booth as the crate foam round's off behind the mic leaving no corners. I recently bought an ionizer fan to keep the room cool in between takes, so I don't have to wait for the ac to start and stop.

Here's my question. I looked at a company that makes professional booths starting at $2995.00. I can buy alot of OSB and foam for that price. (laughing). But I noticed they use what looks to be similar to a computer fan that moves air through a duct within the booth. Hmmmm, I started to think, and I'm curious if anybody knows or have done anytype of DIY project that involves maybe taking like a 4" fan and maybe like a dryer exhaust duct or something and pushing air onto a vocalist with no noise. Even just having a noiseless fan that a condensor mic couldn't pick up (yeh right) would be sufficient. And if not, maybe just share your home recording experiences with vocals.

You can hear current samples from my studio on my profile.
Todd Matherne Official Myspace

Hi Todd,

What I know from my work with room acoustics engineers is that to make air handling quiet you need low velocity, which translates to large cross-section ducts, no sharp corners, and mechanical isolation, so the duct doesn't wiggle the walls/ceilings as air passes through it.

Ken