John Sayers' Recording Studio Design Forum Archive

Hi. My name is Fernando. I'm designing my recordign studio but another problem came up, and it's about modal calculations.

I'm using the 1 - 1.60 - 2.33 mode, but I guess that the sizes that I get from this expression are the internal sizes (without including the wall thickness). A practical example:

The real height of the roof is 4.20 meters, but a false ceiling is going to be posted at 3.95 meters. So with this size should be:

High: 3.95 m
Width: 6.32 m
Large: 9.20 m

or I've to use the 4.20 mts. for my calcules

Thanks a lot
Fernando
AWS

Fernando, this kind of depends on the construction of your false ceiling. The heavier the construction, the lower frequencies will "see" this false ceiling and be affected by it. If the false ceiling is just lightweight plywood, for example, then you'll have modes in the lower frequencies that are caused by both the REAL and the FALSE ceilings. (This isn't a BAD thing - in smaller rooms, there are almost always too FEW modes at lower frequencies. THAT is one of the things that causes colorations of the sound, along with too much or too little absorption in different frequency ranges.)

If you have that much ceiling height, I'd recommend a slanted false ceiling, low in front high in rear of the room - much better imaging, kills flutter echoes ... Steve

Hi Steve!

Thanks for the ultrafast reply!!

Let me see if I understood right... the ceiling could have two height levels, in the front and the rear could be lower but in the middle it would be higher?

I attach a design with this illustrator, is this what you mean?

Thanks a lot again
Fernando
AWS

Cool drawing, Fernando, but "coffined" ceilings have their own wierd acoustics, I don't thing you want to go there. This is more what I meant-

Hi Steve!

Nice draw too!

I think that I got it, more simple than I tough.

I really preciate your help in this topic.
Thanks again!

Fernando
AWS

Hi Again... I was missing something... how much inclination? degrees?

Thanks again!

Fernando
AWS

Hey, Fernando- thanks for the compliment on the drawing, but it's one another member posted. I just borrowed it for an example...

As far as inclination is concerned, it depends on what you're trying to accomplish. For walls, if all you're trying to do is eliminate flutter echo, then a total of 12 degrees will do it. Symmetry would require 6 degrees per wall, so that the angles are the same.

For Reflection Free Zones you need more - also for ceilings, since you can't tilt the floor, you need to make the ceiling at least 12 degrees for flutter echo and more for RFZ.

Generally, for RFZ, you would do more than one angle - you might angle the upper part of the front wall in at the top by 20 degrees, then angle the part of the (false) ceiling that is over the mix position, down toward the front by 30 degrees, and finally slope the rest of the ceiling up to the rear at 12 degrees for flutter control.

These are kind of arbitrary angles, I'd need a drawing of your room (side view, with dimensions, showing console) to actually set correct angles for an effective RFZ - The goal here is to divert all early reflections away from as large an area around and behind the mix position as you possibly can, after which you either absorb the rear wall (small room) or optionally, diffuse the rear (larger rooms only)

Hope that helped... Steve

Hi Steve!

In that case, send my gretting to the author of the draw...

I made 2 models, but I think that you mean other stuff... check out the draws..

Thanks a lot!
Fernando
AWS

Not quite, Fernando - here is a VERY crude drawing I posted elsewhere, easier to just post it again -

Hi Steve! It's me again.

Now we're talking about draws

I made two models, which do you think that could be better?

The Control Room sizes are: 18'x15'x12 (6x5x4mts).


Thanks a lot
Fernando
AWS

Fernando, I've not forgotten you - I'm in the middle of re-doing both mine and my wife's offices (kid's bedrooms) - she's just gone back to school and needs help organizing, and the drawing I referred to for RFZ will take a fair amount of time. Getting there, please be patient... Steve

Hi Steve, NO PROBLEM!!! please, take all the time you need, I came here as one more of the interested people to get a bit of knowleadge, so, good luck with the organization of the bedrooms

Fernando
AWS