Room positioning and acoustics

Archived from groups: rec.audio.pro (More info?)

Hello,

The mixing room/project studio-to-be (well, bedroom) in my new house is
3.3x4.0m, with a bay window at one of the ends, making it more like 3.3x5.0m
(10.8'x13.1' or 10.8'x16.4') respectively. Respectably high ceilings (about
2.4m/7.9').

My question is this - I've heard that in a long room, it's meant to be
better to place the monitors/console/DAW at the one end to minimise slapback
from the wall behind. But if I do this, then either I've got the bay window
behind me (I'd rather work near a window, though I'm not too fussy), or I'm
right at the bay window (reflections from behind the monitors). Do either of
these scenarios pose enough of an acoustical problem that it would make it
preferable to put the DAW on one of the long walls instead?

I have a small budget for room treatment and will probably set up bass
traps, wall-mounted diffusers/absorbers etc, but I can't touch the window.

Thanks!

TJ

Archived from groups: rec.audio.pro (More info?)

TJ,

> I've heard that in a long room, it's meant to be better to place the
monitors/console/DAW at the one end to minimise slapback from the wall
behind. <

Almost. The main problem with a wall that's too close behind you is comb
filtering. This creates numerous peaks and deep nulls throughout the bass
range, continuing through mid and high frequencies if the wall is highly
reflective like glass. Therefore, setting up so the speakers fire the long
way helps because it puts the wall behind you farther back.

> or I'm right at the bay window (reflections from behind the monitors). <

I'd face the window. First, a nice view is always welcome. But more
important, a reflective surface behind the speakers is not a problem because
your speakers are facing AWAY from that surface. I know it's common to treat
the entire front wall with thin absorption, but it's not needed and can even
be harmful. In fact, this is such a common misunderstanding I wrote this
short article to explain the issues:

www.realtraps.com/art_front-wall.htm

> I have a small budget for room treatment and will probably set up bass
traps, wall-mounted diffusers/absorbers etc, but I can't touch the window. <

Diffusors are probably not useful in a room that small. Much more important
is broadband absorption that works well to as low a frequency as possible.
There's a lot of other advice on my company's site linked above. Snoop
around in the Acoustics Info section.

--Ethan

Archived from groups: rec.audio.pro (More info?)

TJ,

> I was hoping you'd be hanging around RAP <

I've been here for years and years!

> So the concave nature of a bay window (and the reflectiveness of the
glass) isn't a problem? <

Concave is a problem, but that's true regardless of where the concave
surface is. Again, the last place to worry about is the surface on the front
wall behind the speakers. Not that it's never a problem, just that it's the
last place.

> What about the technique of putting absorbers wherever you can see the
speakers in a wall-flush mirror <

Yes, that's important too. But the place to absorb is where you can see the
TWEETERS in a mirror, not the rear side of the speaker box.

--Ethan

Archived from groups: rec.audio.pro (More info?)

Jay,

> Not just tweeters - certainly mid domes/cones in 3-ways <

Agreed.

> I'd also extend the treatment to wherever I see the woofers <

Only if the treatment is effective at those frequencies, But you're correct
here too, because some two-way systems cross over pretty high.

> Remember, the ceiling counts too! <

Indeed. Early reflections off the ceiling are just as damaging as those off
a side wall.

--Ethan