Upgrading Our Control Room Acoustics. Current Plan Included | John Sayers’ Recording Studio Design Forum archive

Hello everybody. I’m a new kid on the block. I’ll try to be as thorough as I can. Our studio has been in the same location for 3 years, now. It’s an old, 4 story brick building. We occupy the 2nd floor. We do mostly local indie bands. Noise is not an issue coming in or going out. I am in the process of upgrading our control room acoustics. I probably would have started this months ago, but my wife told me that I didn’t have time to… It’s a good thing she did, though, because I have, since then, found this site and bought some great books. Anyway, it’s a 26.5’(L) x13’(W) x10.75’(H) room with construction as follows: Plaster walls (the front and side-left are exterior) covered with thin wood panel (!), vinyl tile floor on large wood plank (joists run along the width of the room) and vinyl tile on bead-board ceiling. The wood panel on the walls has been covered with tightly stretched fabric, which actually helped the reverb time as well as the looks! We have been working with very minimal treatment. 4’x6’ 2” thick 703 on the side walls. 4’x6’ 4” thick in the 2 front corners. Thick theatre drapes on the back wall. Carpet on the floor. That’s it. The room measurements show a large null in 43Hz and 86Hz along with some issues between 100Hz and 200Hz. The 43Hz and the 86Hz are largely due to the width dimension, which I cannot change. The 43Hz null is compounded by the fact that our speakers start to roll off at around 50Hz. The speakers (Quested S8R) are on stands about 4 feet from the front wall and 3 feet from the side walls. The mix position is at the 38% mark, which was the best measured spot for all speaker positions that I tried. We have a console and two racks on either side. It’s a rented space. There isn’t anything that I’m able to do about the main construction, really. However, I will be building one wall in the front to neutralize a wacky corner in the front right of the room. I’m also going to take the rear wall back 3 feet. After I do this, the room will be 24.5’x13’x10.75’. I already have the HVAC taken care of, but I am really chasing my tail on the treatments. After much research and pondering, these are my proposed treatments. Back Wall: 3’ R38 with 2” 8pcf rockwool face. I’m guessing that this will kill the 86Hz problem. Front Wall: Wall-Wall Corner slat resonators “tuned” to 80Hz-150Hz. I need to leave room for an access door to get into the area that I’m blocking off because the fuse box is in the wacky corner. Side Walls: (from front) 1' R38 w/ 2” 6pcf Rockwool face back to the first 38% mark (all compressed to 1' total), which is about 8 feet from end of corner slats to the 38% mark. Then slat walls angled back 10 degrees and “tuned” to 150Hz to 300Hz running between the two 38% marks. After that, there is the door on one side and a window on the other. I had wanted to do slats down the entire length, but after doing a lot of ray tracing, I could not come up with a realistic angle to keep reflections off of me. I think that the room is too narrow, maybe. The way that I have it now, it’ll keep reflections off of me and the couch, which I want to try placing at the other 38% mark behind me. It’s important to us that the couch sounds as good as possible. Ceiling: 8’x16’ cloud 3” of 6pcf rockwool spaced 3” off boundary starting from the front most part of the room leaving only the strip in the back above the door and window uncovered. I will put a rug on the floor under that spot, but intend to leave the rest of the floor reflective, for now. Ceiling – Wall Corners: 2’x 2’ soffit running across the front and down both sides filled with R38 and w/ 2” 8pcf rockwool face. At first glance, this all seems too much. With the exception of possibly some diffusion on the back wall, it seems pretty balanced to me, though. I can do all of this for about $1,500, so I'd like to keep the budget around there if there are any changes that need to be done. I guess that I’m just looking for a “Go Ahead!” or a “You Are Nuts!” In the pictures, the yellow is insulation as "seen" from the outside. It's black on the inside of the room. I think that everything else is self explanatory. If anyone would rather see a different view, please let me know. Thank you so much for your time and experience, Seamus PS EDIT 4/14/09 It's come to my attention that my intention of tuning the slat walls to such low frequencies may not be realistic. I may have to go another route for the front wall-wall corner units. Any thoughts? PS EDIT 4/17/09OK. Some specific questions. 1. Is the 3 feet of absorption in the back too much or not of the right construction? I don't mind loosing the space if it'll kill 86Hz. 2. Should I worry about making the two new walls (the front and the back wall) by following any special construction rules, or can they be typical 2x4 and sheetrock walls? 3. Are the 2'x2' soffits for the wall-ceiling corners going to be worth the effort, or would I be a lot better off doing superchunks up there? I am trying to minimize rock wool cutting. Thanks, Seamus

Image not preserved: Control Room with slat idea View One Sayers.jpg

Image not preserved: Control Room with slat idea View Two Sayers.jpg