Quick n Dirty DIY HVAC Baffle

Hi All, Contractor's been at my basement studio for almost a week now and in the heat of battle I'd forgotten all about what to do with my HVAC (see my other thread on Superduct). At any rate, I had him make up some baffles out of plywood and soundboard (see baffle1 pic below...it's the lower one). The HVAC airflow in this pic goes left to right. The HVAC airflow encounters little resistance as the baffles are pointing in the direction of flow, while they are angled opposing the noise coming from the studio (right to left). This is kinda like barbs... I was happy enough with the installation until I found out that soundboard is not actually rigid fiberglass, and is instead rigid fiberboard. It doesn't appear to have the same sound deadening properties. So, I decided to fill the sides of the 'barbs' facing the studio side of the baffle with roxul mineral wool, and cover it with fabric to keep the fibres in place. I don't really want mineral wool blowing down on me whenever I'm in the studio. I've attached a pic below. In this one the HVAC air flows right to left. Material cost was very low, and it didn't take too long to construct/install. With the bottom plate attached there is no perceivable change in air quantity delivered to the end of the duct. Does it affect the sound transfer up the ductwork....I dunno yet. Anyways, I thought maybe somebody might be interested in this. Cheers, Kris

Hi John I really like your design. My problem is that I'm building a recording studio in my basement and I need airflow. I just have it framed in. It will be only 7x10 (inside) it's not very big but it's all I need and all I can fit in my basement. My question is how can I get efficient airflow so I don't die but yet keep the sound from leaking out to much? I'm living in a town house and I have six kids so I have to be consider of others. Should I use your idea with some inline fans? If so what fans would recommend? In the construction of the duct should I put some elbows in it to cause resistance to the noise? And what size of duct should I use? Thanks! Lionel