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Dear Forum, I have a home studio that I use for doing sound design for theatre, mixing acoustic theatre (theatrical installations and radio drama) and composing electro-acoustic music. I'm gradually diminishing the reverb in the room and I'd like some advice please on further steps I can take on a low budget (we renovated this house recently so I'm doing things slowly!).

The room has the dimensions: 480 x 350 x 250cm (15.74 x 11.48 x 8.2 feet). My monitors are Tannoy System 12 DMT IIs, a mid-field system. The dual concentric cones of these are placed 2m apart at ear-height with more than a metre away from the rear wall (the 350cm length) and slightly less from the side walls - I used a golden mean ratio - and they sound good where they are now, after having tries various positions in the room.

Behind the speakers is a large double doorway of glass (which can be folded away) and wooden shutters (Venetian style) which are generally exposed when I work. There's another glass/shutter window, a recessed doorway, hardwood floor, flat plaster ceiling and parallel plaster walls

Carpet is a bit of luxury item here in Brazil and I've managed to cover probably about 70% with rugs. I have 3 fairly lightweight foam mattresses placed on the walls to the sides and behind the listening position as a temporary measure.

At present, if clap my hands, I estimate the reverb time to be one second. I'd like to reduce this and I wonder what an ideal reverb time would be?

Right now I have the opportunity to buy acoustic wall panels left over from the refurbishment of a cinema. I don't their specifications yet nor the price, but wonder what sort of of wall coverage forum members would recommend? ie. what percentage - and where.

I'm not trying to isolate the sound, just improve the internal acoustics. I don't have a acoustic testing mic, but I can afford a Behringer if necessary. I have a sound meter though and software to play pink-noise, sine-sweeps etc.

Thanks!

Comments

Space Wed, 01/28/2015 - 18:08

DonnyThompson, post: 424348, member: 46114 wrote: correct me if I'm wrong here, but doesn't an open doorway or window provide 1 Sabin of low frequency absorption/dissipation? In short, is it not in fact acting like a gigantic bass trap, and could it not skew the bajeezus out of the acoustic fingerprint of your room?
 

No idea about Sabins, I am an Auburn fan. But an open door or window is an escape for the longer frequencies so is in effect a bass trap. Conditions matter as Ethan has stated, it might improve or it could couple and present more issues.

What happens is the low frequencies leave and the high frequency bounces off the glass and introduces a mix decision to the brain that says, "no lf...all high frequency."

So the mixer boosts the bass and cuts the highs on the channel in question.

The position of the open area is crucial, it is better suited at the backside of the listening position. At the front side it will defiantly screw up what you are hearing. The leakage of a thin sheet of glass is comparable to a hole, low frequencies will go right thru it, and the placement of a window in want of a balanced symmetrical area has to be considered strongly.

KurtFoster Wed, 01/28/2015 - 18:13

Space, post: 424399, member: 32398 wrote: The leakage of a thin sheet of glass is comparable to a hole, low frequencies will go right thru it, and the placement of a window in want of a balanced symmetrical area has to be considered strongly.

what about a window that is the center of the wall? could one take advantage of the bass loss through the window as a bass trap or is the loss at different frequencies too erratic?

Space Wed, 01/28/2015 - 18:34

If the window is thin enough, bass moves into the tracking room assuming one is present. My personal opinion is that you want all the frequency spectrum to come to the listener position first, so a window, if it were in front of me as we have all seen in high end studios, should be a decoupled laminated glass window with the speakers a good distance from the glass.

This will still introduce high end reflections but is also one of those places where you have to know your room and you have to know your gear.