Corner panels, airtight or not?

Hi Am putting some 705 type panels across my corners. (To start with). But .. do they need to be completely airtight (as it were)? Or can I just put/stand panels in the corner, even if there's a slight gap (a few mms) to the wall, mainly do to unevenness on the wall itself. Superchunks may come later, but I have plenty of panels, so want to try them at first. Thanks. B

hai Bing and welcome to the forum. If you had read this forum you'd already know the answer, so go ahead and train yourself. :) No, they don't need to be airtight. It's even better to have the panels spaced from the walls for low frq absorption. But a total fill will do best. don't worry about gaps of air. After all, the wool ain't airtight too ;)

Ro wrote:

hai Bing and welcome to the forum. If you had read this forum you'd already know the answer, so go ahead and train yourself. :) No, they don't need to be airtight. It's even better to have the panels spaced from the walls for low frq absorption. But a total fill will do best. don't worry about gaps of air. After all, the wool ain't airtight too ;)

If you want it to work like a panel absorber (and you probably want that since it is more efficient and absorbs a lower frequency) then yes, it should be air tight (since the trapped air acts like a spring). If you want to lower the Q-value of the absorber (and also lower the resonant frequency and increase the efficiency) then you want to fill (almost) it with Rockwood. What you do not want is that the wool connects with the panel since that will stop if from coupling with the pressure variation and reduce (or even kill) the efficiency of the panel absorber.

Bing was mentioning just a panel of 705, he didn't make any mention of a pressure/resonatingpanel trapping device. So in that case, no it don't have to be airtight. When making resonating panels, like those that can be found on Ethan's site (with detailed drawings iirc), then yes it better be. as Jens said. I'd do superchunks if I had the wool and put up a panels (of any kind) on the walls when needed.

Ro wrote:

No, they don't need to be airtight. It's even better to have the panels spaced from the walls for low frq absorption. But a total fill will do best. don't worry about gaps of air. After all, the wool ain't airtight too ;)

If the panels are flat against a wall, having them spaced away from the wall will improve their low frequency absorption. If they are across a corner (diagonally), then it is best not to leave any gaps at the sides. However, a few mm don't matter. There is no 'further is better' relationship at corners, in fact it is the opposite. Cheers, Jean

a panel absorber is going to need to be sealed all around. as Ro suggested, you're probably better off with a super chunk style in the corner and then use panel traps if you need them.

Glenn, Bing is talking of 705 panels across corners, not panel traps (resonating devices). Placing 705 or 703 panels across corners, there should be no spacing at the sides, it should stick tight against both side walls, there is no "further is better relationship. Cheers, Jean

agreed

I kind of "misread" the first posting, making me believe he meant the space behind the pannel. Not around the perimeter. So, I agree with big8 in that case :)