I'm building an echo chamber!!!!!

So I'm building an echo chamber at my studio. I figured if I'm going to call it EcohPlant Sound, I may as well. I'm using an iso booth that I no longer use much. Its 9.5 by 5 by 8 feet high. I've stripped out all of the treatment, and I'm just down to the sheet rock. 2 of the walls are angled so there are no parallel surfaces. I covered to walls and ceilings with plaster, but I didn't do it very smooth. Should it be smooth? I thought it would be better to have it uneven to diffuse the sound. I'm going to put some high gloss paint on the walls once its dry, but I want to make sure I shouldn't smooth out the plaster first. I'm also wondering what I should do with the corners I'd like to tame some of the lower mid frequencies, but I'm not sure how. Normally I would use broadband absorbtion. Its there a broadband type of absorption that doesn't kill the HF? I'm thinking of maybe using wood paneling as well as the plaster to give it a bit of a smoother sound. I've only found a few articles online explaining about reverb chambers. Any help would be great. I can post some pics if it helps.

Any diffusion material adds surface area and absorption. Bad for a reverb chamber. Finish to as hard a smooth surface you can. Plaster is good. Newell has a section about reverb chambers in Recording Studio Design. IF you want low absorption, the best way is to Helmholtz type absorbers with low frequency design cut off. Schultz in the IPRF acoustic uses for perforated metals: Principles and Applications is considered the standard for such design work. Reverb chambers can be made with results these days, but you will have to get all the information required. Good luck with your design and build! Andre

I've also read that its helpful to round out the corners. Is this critical. I'm not sure the best way to do it. I'll take some pics, and post them.

cchord59 wrote:

I've also read that its helpful to round out the corners. Is this critical.

Oh boy. Take your time to study a lot. Rounded corners reduce volume and increase surface area, Both are bad. Andre

Ok. Ive read two different articles on echo chamber's stating that rounded corners is a good thing. So It's good I asked.