Improving acoustics in a large 3 car garage

OK- I'm setting up a high powered 5-channel system in my 3-car garage and loving the install so far....

The room has sheet rock walls and ceiling. The ceiling is 14 feet high. The depth is 30 feet and the width is 42 feet. Much of the walls are covered with commercial plastic shelves that are 8 feet high and 2 feet deep (typical man cave storage stuff, paint cans, tool boxes, power tools, etc).

The rear speakers are LE 14" with a 1" compression drivers (2425s) and are mounted on shelves near the ceiling. The fronts are 15" (2226s) with 2" compression drivers (2446) and slot tweeters and are sitting on the floor . The center is a 12" (2206) and 1" (2425) and is shelf mounted about 8 feet high. The sub-woofer is a 18" (2241). The sub is driven by a 1000W plate amp and the others speakers are being driven with Crown 802s (500wpc).

I would rate the acoustics as fair with the cars housed. This AM I pulled out the cars and was AMAZED at how different the sound was... the sound was bouncing all over. The mid and high frequencies seemed to be bouncing everywhere.

The floor is cement.

How can I improve the acoustics of this room?

I assume that placing a few large area rugs on the floor will improve it much. Are there any other "cheap" things I could do to improve the acoustics?

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I wish I could post pics here. No idea how it is done, however. :bouncy:

Diffusion will work better than absorption to clean up the sound in there. Your shelves filled with random man-cave booty will act as good acoustic diffusers. You want to have some diffusion located against the walls at the spot where the first reflection from the nearest speaker occurs. You can determine this by sitting in the listening position and having someone move a mirror along the wall until you can see the reflection of the nearest speaker in it. That's where the first reflection to the listening position will come from and that's where you want to put your diffusion (one of your booty shelves). Do this on both sides of the room. You should also repeat this process for the center speaker, which will have a different first-reflection location, especially since it's 8 feet in the air (which really is too high—you want all 3 of your LCR speakers on as close to the same vertical plane as possible).

You can also put purpose-made acoustic diffusers on the room's ceiling. (Since light weight is of primary importance for ceiling mounting, these are difficult to home-build.) Check auralex.com and atsacoustics.com for ready-made solutions. The mirror trick also works for ceiling placement.

Unless you never plan on putting cars in there, rugs or carpeting will be impractical. If you do go that route, thick carpeting over carpet padding will work much better than just throwing in some area rugs.

Ethan Winer has some good instructional information. I have huge bass traps in all four corners and absorption/diffusion in select areas and the bass is tight and the room isn't too dead.

The ringing your having with the cars removed is probably from the large, reflective floor/ceiling surfaces.

But what a great space for a system! :applaud:

https://m.youtube.com/watch?v=lbLVjHfHahg

http://ethanwiner.com/acoustics.html