John Sayers' Recording Studio Design Forum Archive

OK, I'm definitely a newbie to this discussion forum so I hope my flame retardant suit is up to the challenge

I'm a DIY speaker builder, and after years of listening to commercial monkey-coffin boxes, have been fabricating a series of bipole and rear mouth back loaded horn enclosures. It's not likely I could ever again settle for a simple direct firing system.

Circumstances have recently required I migrate my audio system ( 2 channel only) to a former basement bedroom. The previous room was much larger and while not without some minor issues (due mostly to concession to "wife acceptance factor" ), it was quite tolerable.

Approximate dimensions of L-shaped room:

8'3"wide x 23' long, 7'6" to suspended ceiling, with a unfortunate structural beam/ventilation soffit (8"x20") across the width of the room.
Two exterior walls are half height concrete, 2"x6" stud walls with raw 'glass batts/ vapor barrier / 1" styro / 1/2" gyproc. Interior walls are single layer 2"x4" stud framed/ raw 'glass batts/ 1/2" "donnaconna" fibreboard/ 1/2" gyproc.


It became immediately apparent that rear and side-wall mid/HF absorbsion/diffraction is required, for which the designs and implementation examples are easily understandable. My main question is without completely reconstructing the room, how to implement wideband treatment on the rear / side walls.

All of the loudspeakers in my current and future planned collection are either fullrange bipoles, rear loaded horns or open baffles. The compact horn enclosures in particular are designed specifically to use the room corners to complete the final flare / mouth of shortened horn.

something like this:

* pardon my computer skills, I couldn't get it to properly display in post.


My initial intuition is that (diagonal) corner mounted bass traps that seem to be a standard technique would seriously limit if not completely destroy the room's contribution to the LF extension of these designs.


Any comments or observations appreciated.

here's your picture.

For posting the picture - the resolution has somehow deteriorated in the process, but it still shows the basic configuration of the enclosures in relation to the the corner walls.

So I'm back to my initial question - how would I go about applying wideband/ bass treatment to the front end of this room?

Ceiling to side wall mounted diagonal and front wall vertically mounted taps?

Try using the horizontal corner at the wall/ceiling intersection. To provide some additional control, you may want to consider some additional control in the rear vertical corners, but with an FSK face attached so you don't kill the mids and highs in the back of the room.

I'd recommend 1 soft absorber between the speakers on the front wall. This won't kill the rear wave too much but will help with other issues since you have a proximity issue to that wall and SBIR issues will be rampant.

If at all possible try not to aim the rearwave directly into the corners - that will only exacerbate the problem. This may not be possible due to the narrowness.

If it were me, I'd seriously consider pulling them way out into the room and attempt a more nearfield listening setup.

Bryan

Bryan:
Thanks, that's more or less the direction I'd considered.

As pulling the speakers out for more near-field position; that works well enough in this room for mono-poles or even a bipole MLTL, but the horns rely on the corners to complete the final flare - without it they are rather thin at the bottom.

Sounds good. Thought maybe if they were still close to the side walls you might get enough reinforcement to allow them to breathe a bit in the back and help the soundstage depth.

Bryan