John Sayers' Recording Studio Design Forum Archive

Hello....I have been searching around to find out how to calculate the dimensions for a corner slot resonator for a few specific frequencies. My room is 23' L x 15'7" W x 8' to 10' peak H (the peak runs length wise) and I have put the dimensions through a room mode calculator and found that around 70 hz, 120hz, 180hz, and then from 225hz to aroun 400hz seem to come up as being the frequency problems.

First question is how do I decide on the dimension of a corner slot resonator to tune to the lower frequencies.

Secondly should I tune one in each corner differently or 2 and 2, or all 4 the same?

What would be best to absorb the 225hz to 400hz range....I was thinking some aborber panels on the wall consturcted of 703 fibreglass or of mineral wool?

thanks

think broadband. vary the slats and slots on the resonators. for the higher range the porous absorption will be useful and again think broadband. wait until you take room measurements before undertaking any focused treatments.

Hi, i've got the same question. My construction of the control room is done. Put already some treatment in, but still a lot of boosts or cancelations.
This is the current result: My room size is:
365 cm length
245 cm width
239 cm hight

As you can see on the pictures: I have some traps already (the black once are going to be replaced with new ones like the purple)
It would be nice if i can transform the SuperChunk corners into slot resonators to tame more low frequencies.
Let's say i want to tame the range 73 Hz - 700 Hz how to determine how much slats and slots to use.
When i use a calculator and try to find settings for 73 Hz i have found:

Slot width: 3 mm
Slat width: 150 mm
Depth from wall: 420 mm
Slat depth: 22 mm

and for 700 Hz it is:

Slot width: 100 mm
Slat width: 22 mm
Depth from wall: 420 mm
Slat depth: 10 mm

Is only 1 combination enough for that frequency? How to fill up the rest...with what sizes?

Im a little desperate. I don't know what to do next. Or is this response fine? I don't thinks so...

Regards,

Jeroen Wolff

but still a lot of boosts or cancelations. This is the current result:

That's actually not too bad at all! You have the scale zoomed in pretty tight, with each division being only 2 dB, so you are within +/- 4dB from 110 Hz up (except for that one dip at at about 680 Hz, which is very unlikely to be modal anyway). So that's really quite good. Your response doesn't extend any lower than that because that's probably approaching the limit of your speakers, and you don't seem to be using a sub.

Having said that, the graph you show is only frequency response curves, which tells you very little about modal behavior. You should be looking at the water fall plots and spectrogram to see those. You should also be looking at the impulse response graphs and RT graphs, to see how the room is doing in terms of reflections getting back to your head, and overall decay times. Frequency response is only a small part of the whole acoustical picture of your room.

It would be nice if i can transform the SuperChunk corners into slot resonators to tame more low frequencies.

I wouldn't do that, as it would create large reflective surfaces behind your head, which isn't a good idea. You could perhaps put some slats across there, but small and widely spaced, to improve the diffusion at the back of the room, and maybe give you better termination of the ITDG, but the IR graphs will help you decide on that.

Im a little desperate. I don't know what to do next. Or is this response fine? I don't thinks so...

It would help if you post the entire MDAT file, as well as details of how you took those measurements, and how your speakers are set. With that info, we can analyze better what is happening in your room, and see how good or bad it is. But based on the frequency response curves alone, that isn't too bad.

- Stuart -