In part 3 of this series on DIY studio acoustics we got deep into spreadsheets and calculators to help us get a balanced acoustic treatment that didn't favour one or more frequency bands over any other. In this part we will take a look at how I handled the difficult issue of ventilation and cooling.
Get The Heat Out
I have a floor to ceiling 19" rack and a computer cupboard and so rather than pull the hot air out of these two into the room I decided to create a negative pressure by sucking the hot air out of the computer cupboard and rack through very long and wiggly ducts to the outside world. I also ran the two fans in series so that they would run slower and so not make as much noise..
Obviously I needed a route to bring fresh air into the studio so I added another long and wiggly duct, all of which I lost in the roof space about the studio, to allow the negative pressure set up by sucking air out, to draw fresh air in. So that resolved the ventilation and helped to reduce the heating effect but pulling the hot air straight out.
But I knew that with good sound isolation comes good thermal insulation, and so I would need additional cooling. Doing this on a budget, I bought a low cost 10,000BTU stand alone air con unit, the sort that are free standing in the room and push the hot air out through a duct through an open window. Now the open window idea was a non starter in a studio! It would have destroyed the isolation. What I did instead, was have the air con unit in the roof space away from the studio and to attach ducting to it so I could duct the cold air out of it, into the studio, pull the warm air out from the studio and back into the unit. Then route the heat output from the air con to the outside world using roof vents. I then modified the controls so I ended up with a simple on/off control, but with an air con system I could have on whenever I needed it, except for the most critical of recording for about £200.
I hope this series has given you some ideas and inspiration to help you improve your studio acoustics on a budget. As I said at the outset, I am not a trained acoustician, but I have a good engineering background and understanding of the issues and when I measured my studio I was vey pleasantly surprised that it was remarkably close to the predicted performance. I have used similar techniques for several other studios and found they too performed closely to the predicted results.