building room within a room

[Frosty]

I am building a room within a room for a rehearsal/recording room in my garage.
interior dimensions are 20x19width x8 1/2"height
I planned on building the walls a few inches away from the existing walls,
Will I have standing wave issues with these dimensions?
If so is it necessary to build the walls at angles?
Don't want to lose too much useable space unless it makes a large difference in sound quality
Any advice is appreciated Thanks - Frosty
I'm a drummer!

[Soundman2020]

Hi. Please read the forum rules for posting (click here). You seem to be missing a couple of things!

I planned on building the walls a few inches away from the existing walls,

But do the math to make sure you tune the walls right, and have enough isolation.

Will I have standing wave issues with these dimensions?

Yes. You will have standing wave problems with ANY dimensions! Contrary to popular belief ALL rooms have modes. The simple act of erecting walls means that you have standing waves (modes). You cannot "get rid" of modes by using certain magical dimensions. All you can do is to ensure that the modes are fairly evenly spaced across the low end of the spectrum.

Use one of these Room Ratio calculators to figure out the best dimensions for your room:

http://www.bobgolds.com/Mode/RoomModes.htm

http://amroc.andymel.eu/

Both of those are very good, and will help you to decide how best to build your room. They give you tons of information that is really useful to help figure out the best dimensions.

If so is it necessary to build the walls at angles?

No. That's a myth. Angling walls does NOT eliminate modes: it simple makes them appear at a different frequency. Angling walls can reduce flutter echo, provided that the angle is more than 12°, but that wastes a lot of space, and there are much, much simpler ways of dealing with flutter echo.

Don't want to lose too much useable space unless it makes a large difference in sound quality

As long as you have a reasonably good room ratio, away from the bad ones, that's fine. It is more important to have as much air volume as possible inside the room, than it is to have a "perfect" ratio.... especially considering that there is no such things as a perfect ratio....

- Stuart -

[Frosty]

Stuart, thank you so much for you advice. I will be checking out these links tonight
Happy New Year!

Frosty