Best Way To Deal With A Square Room?

[flayerhater]

So I've found a new home builder, in my area, in my price range, who is actually willing to soundproof a garage if I buy from them. Problem is, the garage in question comes standard as a 23' x 23' square. 9' ceilings.

Without deviating from the original design too much (these are 2 story cookie cutter homes, with hardly any free space surrounding them), they might be able to make the dimensions slightly different. Or just the room-within-a-room size a little different. Problem is, I have no idea what better dimensions would be. And I wonder if I wouldn't be better served simply keeping all the available space, using lots of DIY treatment, and using freestanding sound control panels on wheels. To change up drum sounds, for example.

This room will have loud bands. With close neighbors. I want drums to sound great. Favor 1 big space. I don't want a control room. A vocal booth could probably be useful.

Welcome any suggestions on the best way to proceed

[Soundman2020]

So I've found a new home builder, in my area, in my price range, who is actually willing to soundproof a garage if I buy from them.

Well, that's good news... I guess! Provided that the guy actually understands what "soundproofing" means! The vast majority of contractors don't have a clue about that. They think it just means to add an extra layer of drywall, or using some type of magical material that their supplier told them about... They have no idea that reality is very different! They don't get that true "soundproofing" for a studio means adding a lot of additional mass to the outer-leaf of the garage, then building an entirely separate second frame inside the room, a short distance away from the existing frame, taking great care to have no mechanical connections between the two, then putting at least two layers of drywall on that new frame, with Green Glue in between, then sealing everything air-tight, then sealing it again, then installing the sound-proofed HVAC system at the same time, as well as the paired, sealed, massive access doors, and the soundproofed electrical system....

Tell you what: to see if this guy understands what is meant by "soundproofing", ask him what MSM resonant frequency he plans to tune the walls and ceiling for... if you get a blank stare in response, you'll know that he doesn't have a clue....

Without deviating from the original design too much (these are 2 story cookie cutter homes, with hardly any free space surrounding them), they might be able to make the dimensions slightly different. Or just the room-within-a-room size a little different. Problem is, I have no idea what better dimensions would be. And I wonder if I wouldn't be better served simply keeping all the available space, using lots of DIY treatment, and using freestanding sound control panels on wheels. To change up drum sounds, for example.

You seem to be mixing up and confusing several different concepts all at ounce!

First, the relationship between dimensions affects modal response, period. It does affect what you might need to do to improve the sound of your drum recordings. Modal response refers to the way standing waves form and interact inside the room. It refers to the large peaks and troughs in the response of the room caused by those standing waves, and also to the sustained decay ("ringing") of certain specific frequencies. Changing the dimensions or shape of your room does NOT eliminate standing waves: It just means that they will form at different frequencies, and in different locations in the room. In other words, different notes will ring at different intensities, but the problem will still be there.

Modal response is more of an issue for control rooms than live rooms. It's not a bad thing that the live room has a bit of "character", some of which will be due to standing waves. The issue is not to try to eliminate them from a live room, but to control them usefully.

If you do plan to change the dimensions to help do that, then the key is to make sure that no dimension of the INNER-LEAF room is exactly the same as any other dimension, no dimension is an exact multiple of any other dimensions, and no dimensions is within 5% of being the same, or being an exact multiple. As long as you achieve that, you'll be OK. Especially considering that the roof is reasonably large. There's no need to change the dimensions of the actual building, but you could if you wanted to: make one of the walls 21'6", instead of 23', for example, and you are outside the 5% window. YOU could do that with the inner-leaf, and you'll probably need to do that anyway, in order to leave space for the wall that seals of the garage doors....

Also, if you can change dimensions slightly without too much hassle, then ask for a 10' ceiling, instead of 9. Or even 11, if you can! The higher the better....

This room will have loud bands. With close neighbors.

How loud? How close? Bur regardless of the exact answers to those, that already defines one thing: You will need MASSIVE walls with LARGE air gaps. That's the only way to get the MSM resonance down low enough, and get high levels of isolation.

I want drums to sound great.

That is absolutely unrelated to the issue of isolation. That is about the acoustic design of the room interior, not the isolation system. To sound god, drums need high ceilings, a lot of space around them, and good treatment to keep them live but not overbearing, looser in the low end but not boomy, snappy in the low-mids but not echoey, etc.

I don't want a control room.

So no tracking, recording or mixing at all?

A vocal booth could probably be useful.

If you have a vocal booth in there, then that takes care of your dimensions / modal issue, right there!

- Stuart -

[flayerhater]

You will need MASSIVE walls with LARGE air gaps. That's the only way to get the MSM resonance down low enough, and get high levels of isolation.

Thank you very much for the response

How large of an air gap would you suggest? A couple inches? 1 foot?

[Soundman2020]

How large of an air gap would you suggest? A couple inches? 1 foot?

That depends on how much isolation you need, and what frequencies you need it at.

Here's the equation:

MSM-resonance-equation.jpg

Considering typical conditions, it is possible to simplify that a bit by replacing some variables with constants, so the simplified version of the equation is:

Fc=c[(m1+m2)/(m1m2d)]^.5

where:

Fc=resonance frequency (Hz)
c=constant (60 for empty gaps and 43 for with insulation)
m1=mass of first leaf (kg/m^2)
m2 mass of second leaf (kg/m^2)
d=interleaf spacing (m)

For imperial units the constants are 170 and 120.

The reason for two different constants is that no insulation, the air acts adiabatically. With insulation isothermally.

As you can see increasing the mass will lower the resonant frequency, and increasing the gap will do the same. So you can play around with various values for each, to optimize for your situation. If you have acres of space and don't mind losing some of it for better isolation, then it makes sense to have large air gaps with not so much mass. But if space is tight, then it makes sense to increase the mass substantially in order to reduce the air gap.

- Stuart -