The best Corner Trap for bass control under 125 htz

hi all, recently started mixing a few things in my new control room. i've been on a tight budget so i haven't been able to put any sound control in yet. my main concern is the bass cancelation. it's most noticable in the 40-100 htz range. (boomy mixes in the car and every where else). i know why it's happening, and i know i need a bass trap, and the room was built with that in mind, but from what i am reading about panel absorbers, even the 4 inch thick 703 ones aren't that effective below 125 hrtz. i have thought about doing the superchunk sticky ( http://www.johnlsayers.com/phpBB2/viewt ... highlight= ) with 703 in triangles in the corner. would that be effective? what about with a plywood panel membrane in front of it? here's a picture of the control room to give you a better idea. the ceiling is 8 ft high, just your basic ceiling tile, with probably 10 feet above that to the real roof. what would you recomend?

Superchunks work really well. If you have the budget for 703, go for it, though rockwool or cotton might be less expensive and give similar performance. In a room that shape, I'd focus on the corner directly behind the mix position, I think that one might be the most important because a lot of the sound will accumulate back there. That said, do as many corners (including wall/ceiling) as you can manage. I'd do normal superchunks on all corners, and put a big absorber on the rear corner, both to act as a bass trap and also to absorb rear reflections. Also because of the shape of the room, you'll need to work extra hard at taking care of side reflections.

thanks, yeah i was definately going to put it in that corner. do you think i should space a plywood panel out infront of it? would that help?

not sure what you mean by plywood panel, but I probably wouldn't do it. If you mean a membrane absorber, I think there are better solutions (namely superchunks and slot resonators), especially for smaller rooms. If it were my room, I'd do superchunks in the corners, with a big chunk on the back corner to absorb rear wall reflections, and put slot resonators tuned to some of the problematic frequencies of your room on the side walls.

thanks!

also keep in mind that the back-side walls will reflect so you need to put some absorption at those reflection points to keep things balanced.

Definitely absorb a WIDE area across that rear corner - except for low bass, any sound that enters a 90 degree corner will be reflected right back out parallel to the incoming sound - so you'll get all sorts of cancellations at the mix position with your left speaker trying to cancel out your right one, and vice versa. I'd put at least a 6 foot wide, THICK absorber all the way across that corner and hope it's enough... Steve

You may want to take a look here (scroll way down): http://www.johnlsayers.com/phpBB2/viewt ... 2&start=60 I am building a room similar to yours. That corner is a real nightmare if left untreated. I am bulding this corner trap according to knightfly recomendation.

thanks orange. one question: what are you building your false wall out of? sheet rock or just plywood? and are you going to space it out from the triangle rw at all, or just push flush?

The false wall won't be a hard surface, it just can't be. I now realise i shouldn't have call it a "false wall" then :oops: ... As Knightfly mentioned anything that goes in that corner will be reflected back to the listening position. So the "so called" false wall will be a 2X4 frame filled with rockwoll then cover with cloth. For a start i'll do some test with the false wall against the rockwoll in the corner. If this isn't conclusive i can move the false wall further away form the corner and add some RW if i need to. A corner trap like this is more of a broadband absorber than just a bass trap, it is effective on the whole spectrum. The deeper it is the lower it will absorb. I obviously don't know how you room sound now, but i just can't imagine you don't have serious phase cancellation probs. and poor imaging without anything in that corner. My room without any acoustic treatment in that corner is unworkable. But hey what do i know ! We're are just in the same boat i guess :wink: