A few questions; Small studio: Diffusors, Reverb

Hello, I am remodeling my one room studio - I pulled up all the carpet, cleaned everything out. My goal is a natural, live sound, with a nice short decay in the room. I am tired of carpet and foam. I have three superchunk bass traps, and the "new wall" in my drawing is a portable wall left over from my vocal booth. It is two layers of drywall on one side of a wood frame. I also have a 4' x 5' x 3/4" MDF board with foam on one side and bare on the other, to control the acoustics a little more. Questions: 1) Should I place DIY diffusors (various depth wood) in the room? Where? 2) Should I put another bass trap in the unused corner? 3) How should I place my foam? Ceilings, walls, or both? Foam on ceilings, diffusion on walls? Or don't use foam and hang clouds instead? 4) Alternatively, do you think I should take a totally different approach (move the desk, move the new wall)? I appreciate any feedback, I'm doing work on it this weekend. I can really only afford insulation and various wood for diffusors/reflection control. No soffits, new walls, etc. Thank you! John

My goal is a natural, live sound, with a nice short decay in the room. I am tired of carpet and foam.

OK - let's get a few things straight. You said "nice short decay" Put your room dimensions into This reverb calc. Average your shorter walls say 20' x 11.5' x 8' (I assume it's 8' - you didn't mention your height). Put in Gypsum Board for walls and ceiling and timber for floor. @ 4khz it's 1.1sec @ 2khz it's 1.38sec @ 1khz it's 1.98sec @ 500hz it's 1.51sec @ 250hz it's .91sec @ 125hz it's .36sec. as you can see that's not a nice short decay, nor is it an even decay as it's longer around 500 - 1Khz than at 125hz. In fact 125hz is where you want it cos that's a nice short decay. Gypsum board is already a bass absorber. Now put the heavy drapes (the closest to 703) on the front and back walls and you get a more even decay around .5 sec. NO bass traps needed. It sortta speaks for itself doesn't it. Geometry is another story as it pertains to stereo imaging. cheers john

Thank you for the reply John. I want to follow your advice closely on that. 1) Does this seem to fall in line with the advice? I'll leave the left wall as is, with two bass traps and totally covered in foam. Instead of doing another wall totally in foam, I think I will alternate foam pieces on the other two opposing walls, sort of an inverse checkerboard pattern on the two walls. 2) I am also planning on adding diffusors at the spots indicated. Is this a positive step for this room? 3) Now, what should I do about treating the ceiling? Should it be mostly covered in foam? Or left bare? I am worried about flutter-echo / comb filtering. BTW, I apologize for not including my room height in my first post. It is 7'6". Thank you, John Shryock

Yeah - put your diffusors at the back of the room to keep the highs there. your room is long enough. cheers john

man. i just built a skyline diffusor using the PME records guide (link) and it took a really long time. I will probably spraypaint it, because it looks a little rough right now. Anyways, I am going to try building a different diffusor type (link), and see if it is much faster to build. If that takes way too long also, I guess I'll try the design with bent masonite or plywood between two 2x4's. I really was looking forward to good diffusors, but I can't spend all my time building them! How much wallspace should be covered by diffusors in order to make an appreciable difference? Thanks, John

John - personally I don't think you need diffusors - but you seem determined. I'd spend the money lining the whole of the right wall with 703 as i showed in my first post. cheers john

Yeah, I was pretty determined. And if it didn't take so long, I'd probably still be very determined. But I will not do diffusors at this point. I guess I am just worried about the room being too dead again. My room was lined with auralex, and the floor was carpeted. I really don't want that again. Anyways, attached is the current plan. Just a little shelf with my DIY diffusor on top. Just to clarify, this is what you originally posted, as far as the 703, correct? The next main concern is the ceiling. All of my reading back posts suggests making the ceiling very dead. I can completely cover it in foam, but again I'm worried about the "deadness." However, I am concerned about slap/flutter echo. What about hanging some boards at a 15 degree angle? Or, are my concerns unwarranted? Should I just leave the ceiling bare? Thanks for your time. Your help is assisting me greatly. John

John - I've been saying you don't need diffusors in a control room, as has Moulton. Diffusors are only necessary where the room is large and the people at the rear of the room are missing out on high end. that's why you see them in large control rooms. For me geometry is an important part of the design - maybe try something like this?? cheers john

Thank you again! Any comments as to treating the ceiling? With a bare floor, is it best to have absorption covering the ceiling, unless the ceiling is sloped? Would a checkered absorption/reflection pattern on the ceiling be best? Or should I kill all chances of floor/ceiling flutter echo? I also have some auralex minifusors which i could put on the ceiling, I think I may try that. I guess they'd work over a similar frequency range as foam would. Tomorrow night and this weekend I will be doing more work on the room. As always, this site is fantastic and I appreciate the advice. - John