John Sayers' Recording Studio Design Forum Archive

Can I just make one slat resonator on each side of the wall angling them 6 degrees and up towards the front of the control room rather then making a couple of modular units side by side?
A instead of B

Actually that's a BETTER way to do them in some ways; the longer surface before repeating means that longer wavelengths will still see the resonator as an angled wall.

However, if you're using them not only to control flutter and to absorb at a particular frequency, but ALSO as part of a RFZ monitoring system, then they should be angled more than 6 degrees; for that purpose, you would need to do some basic geometry sketches so you know the angles that will actually eliminate the need for absorption at those first reflection points; it's likely to be more like 12-18 degrees depending on speaker positions, etc, and the only way to be sure is to draw everything to scale and measure the angles.

There's a bit more that should be pertinent here -

http://www.johnlsayers.com/phpBB2/viewt ... c&start=60

HTH... Steve

That was my doubt also. Long slats or several short ones....

The other thing I'm in doubt is:

Is it better to have a few broadband resonators or to tune each one for certain frequences ?

Like, I have issues with 125, 500 and 1000 in my room, of course the frequences between them will need to be absorbed as well. So maybe it's good to have 3 different ones covering, lets say, 125 - 300, 300-500, 500-1000 or 3 centered on the main frequences?

I'll use John plans for the room, any idea which frequences the basstrap absorbs?

thanks a lot!
Fabio

Is it better to have a few broadband resonators or to tune each one for certain frequences ?

In almost all cases, it's better to first use broadband absorption (just absorption, NOT Helmholtz or panel traps) in corners, including wall-ceiling corners, to bring ALL modes down in level; also ceiling absorption to kill flutter and minimise phasing problems at higher frequencies in mics, due to close proximity (early reflections) to the ceiling.

Then, if the room STILL has specific problem frequencies (by MEASUREMENT, not calculation) you can design frequency-specific treatments.

One exception John has noted, especially for drum rooms, is the typical kick drum shell mode of around 300 hZ; for that, and to keep from deadening a room with too much broadband absorption, a tuned slat has worked consistently well.

I'll use John plans for the room, any idea which frequences the basstrap absorbs?

Without slats or other stuff on the front of the absorbent, any broadband trap will absorb well down to maybe an octave below the frequency related to its 1/4 wavelength; in metric system, wavelength (in meters) = 344/frequency (hZ), so for 120 hZ, wavelength would be 2.87 meters, 1/4 wavelength would be 2.87/4 or 0.72 meters.

That would be the depth from the FRONT of the absorbent to the back wall, with no hard panels between those two points. Absorption would actually continue for probably an octave (useful) below that, and further for any NON-perpendicular waves; however, at that low a frequency sound is a PRESSURE change in a small room, not really a wave at all, so straight absorbent isn't as effective as tuned devices.

HTH... Steve

knightfly wrote:However, if you're using them not only to control flutter and to absorb at a particular frequency, but ALSO as part of a RFZ monitoring system, then they should be angled more than 6 degrees; for that purpose, you would need to do some basic geometry sketches so you know the angles that will actually eliminate the need for absorption at those first reflection points; it's likely to be more like 12-18 degrees depending on speaker positions, etc, and the only way to be sure is to draw everything to scale and measure the angles.
HTH... Steve

Thanx Steve,
Is that 12-18 degrees for each side or both sides combined?

The REST of that sentence - " it's likely to be more like 12-18 degrees depending on speaker positions, etc, and the only way to be sure is to draw everything to scale and measure the angles. "

And the link again -

http://www.johnlsayers.com/phpBB2/viewt ... c&start=60

This isn't something I can give you a "cookie-cutter" fix for; you WILL need to follow the example on the link, and apply it to YOUR SPECIFIC floor plan, sorry... Steve