John Sayers' Recording Studio Design Forum Archive

One of the main resonances of typical kick drum shells is around 300 hZ, which makes it sound like your nulls are real - for the tests, were you using both speakers or just one? you can get some wierd comb filter effects using both.

As to height, if you can't raise things how about lowering them? You're sitting within 2" of dead center vertically, you get enough nulls left to right by having to maintain a symmetrical stereo field. Although you'd need to lower things by about 6-8 inches in order to escape the center null, which would be nulled at around 70, 210 and 350 hZ for vertical center.

If neither raising or lowering head/speakers is an option, maybe a sloped "cloud" with plywood backing; this should help minimise the "centered" effect vertically, while improving RFZ effects a bit. I'm thinking at least 2" 703 over at least 1/2" plywood (full sheet), nearly touching the ceiling toward the rear of the room, and 4-6 inches off the ceiling toward the front, centered over the mix position -

It would be fairly easy to first find out if vertical placement is the problem, by just temporarily putting some blocks under your speakers and raising your chair for a brief test - if it doesn't improve the nulls, then we're likely looking at SBIR effects, which I've not gotten time to finish scaling your room to examine... Steve

Knightfly,
Hate to sound difficult, but I'm afraid lowering the speakers 6 to 8 inches would put them too low behind the console.
In addition to improving the balance at the critical mixing position; another objective I have is to widen the usable listening area so that when two people are seated at the console or people are in different locations in the room the sound is fairly consistent overall.
Just so I understand; by installing the 'cloud' you spoke of, your objective would be to manipulate the relationship between the speaker-to-ceiling and speaker-to- floor distance by creating an artificial ceiling area? My ceiling already rises 13" in 11 feet, the low end being at the wall the speakers are next to, and rising to a greater height behind the mix position. The 'cloud' would increase that angle.
Just brainstorming... an idea I saw used in one of the higher profile Chicago studios was utilizing the dead airspace below the floor by creating openings between the studio and airspace. As you can see from my control room elevation, I have an air space between the lower joist ceiling and the bottom of the trusses of the outer structure. I have no idea if this would be useful at all but would consider using this airspace even if it compromises the control room sound isolation somewhat. Probably a stupid idea...
Christopher

Yeah, I was afraid lowering things wouldn't be doable - I still need you to try raising them a few inches just as a test, so we can put the height thing to rest and move on.

I didn't notice the existing splay on your ceiling, thanks for pointing that out.

May get time to finish the other dimensions/vs nulls model later tonight... Steve

Knightfly,
Since raising the monitors really wasn't feasible, I lowered the Genelec S30-C's (Genelec's are my primary monitors) and flipped the Tannoy System-8 Dual Concentrics over (use Tannoy's as secondary monitors, mostly to check vocals in mixes) so that the center of the woofer cones were 42-1/2" from the floor and 54-1/4" from the ceiling. This repositioning afforded no improvement in the low frequency response at the mix position. In fact it imparted a nasely midrange honk to the sound of the monitors.
I returned the monitors to their origional positions except this time I moved them as close to the wall as possible. This seemed to improve the overall sound and stereo imaging a bit; still no improvement on the bass response however.
The present position of the monitors is 49-1/2" from the floor, 46-1/2 from the ceiling, 78" center to center (to woofers) on the Genelec's and 52" center to center on the Tannoy's.
Distance from woofer to listening position- Genelec's 78", Tannoy's 75".
At mix position, ear to floor distance- 48", ear to ceiling distance 53".
Hope this is useful information. Christopher