Colin's Acoustic Treatment Adventure

Well hello to all of you. Many months of viewing, reading, learning and stressing have finally gotten me to a point where I have successfully soundproofed my converted garage to my purposes. It meets my needs in that regards, and I can’t thank you enough for all of your thoughtful posts and responses that have helped me get through one of the most challenging experiences of my life. Due to the need to keep my space fairly conventional (no non-parallel walls, etc.) I am currently faced with acoustically treating a 19’ x 10’ rectangle with a 10’ x 4.5’ “iso room.” I do not wish to do any more construction and would like to get the best possible acoustic solution for this room. Use: This room will be used primarily as an overdub/edit/composing/mixing suite for my own personal use. It will be a light commercial room catering to the above needs. As I already mentioned, I am satisfied with the sound proof performance as I work in 80 decibel range or lower. The floor will be laminate wood on top of a sub floor on top of a cement slab. Challenge: How do I best treat the room for optimal acoustic performance? I have viewed post after post and have some very good ideas but would love to get a sound off before I implement. The biggest challenges (as seen in the picture below) are as follows: The French patio door to the side of the room that limits the forward position of the mix desk The heating unit that protrudes 6 inches out into the room on the same wall The door placement on both the front and back wall The ceilings of a short 7.5” I interpret these challenges in that I will have a hard time treating front to back reverberation, mixing in a node and finding a way to appropriately treat the iso room due to it’s oblong size. I am not interested in any more construction (i.e. framing, drywall, etc.) so I will work with what I have. There are perhaps other issues, which I am hoping the tireless readers of this forum will help me uncover. I am planning to orient the mix desk roughly in the middle of the room facing the iso booth, with a cloud over the mix desk. I have the plans for most of the DIY absorbers, corner traps, etc. off of this site but would like most to get an idea of how best to implement them. My budget for the acoustic treatment is roughly $1500.00 but would very much like to use as little of that as possible. I appreciate all of your time for reading my humble studio post and hope that you will be able to help me. I will answer any and all questions ASAP. Thanks in advance.

By the comment "no more construction", do you also mean you don't want to build any DIY treatments? You're gonna need something to kill flutter between parallel surfaces. Also, modal distribution for those dim's isn't exactly ideal, you'll probably need a bit more low bass control than some rooms (looks like possible problems around 40-50 hZ, with a slight "hole" just above that range) For some ideas on DIY treatments (if your answer to my first question was NO) check out the acoustic forum stickies. You don't want ANYTHING centered in your room except from side to side for stereo balance; if you're doing surround, more absorption will be desirable than if just doing stereo mixes because rear surrounds can otherwise cause early reflections back to the mix position. In the acoustics forum, check out my sticky "are my speakers in a null?" for more on positioning stuff. Also, if you haven't already, click on the John Sayers productions logo at top right of the page, then click on "wall units" - the saw-tooth ones will probably be necessary near your mix position to control flutter; those may also help some of your low end modal problems if tuned right, but I think that may be too low a frequency for slat absorbers to help much; more likely you'd need some tuned panel absorbers, but I'm off to bed for now so it may be a while before I have time to help you calculate specifics and positioning for something like that; they won't help anything if not in the right pressure zone. Gotta run, HTH... Steve

Steve thanks for the reply. Actually I am fully planning on the DIY units to a degree. My carpentry skills are improving daily, but I am not yet all that great. I knew that there would be problems, but I hope that I am able to overcome them. Thanks!

Colin, > How do I best treat the room for optimal acoustic performance? < This is a deep subject, and a complete answer requires far more than will fit into a single reply here. The short version is: * Broadband (not tuned) bass traps in as many corners as you can manage, including the wall-ceiling corners. * Mid/high frequency absorption at the first reflection points on the side walls and ceiling. * Some additional amount of mid/high absorption on any large areas of bare parallel surfaces, such as opposing walls or the ceiling if the floor is reflective. That's about it. Really. > The French patio door to the side of the room that limits the forward position of the mix desk < You can hang an absorber on the door, from wires attached to the ceiling, or on a stand you can move when you need to use the door. > I am planning to orient the mix desk roughly in the middle of the room facing the iso booth, with a cloud over the mix desk. < The middle of the room front to back is the very worst place you can be. Also, a cloud should not be directly overhead, but about halfway between you and the loudspeakers. It can be larger, but the main "first reflection" points are halfway between your ears and the tweeters. The drawing below shows the optimal placement for the mix position and for the first reflection treatment. It doesn't show any bass traps, but understand that you need as many as you can possibly manage. Put them all in corners, including where the walls meet the ceiling. (And even where they meet the floor if possible.) --Ethan

Ethan Thank you so much for taking the time to reply. I do understand that this is an incredibly deep subject and one that is not easily solved. I suppose what I am specificially looking for is how to best tame this specific room, with my limited carpentry skills, while still spending less than $1500. If there are specific placements that are recommended, specific products, projects of the DIY sort, etc. that can be passed on to me. I have put together a rough idea of how I would initally interpert your information in just the mix room. I am wondering if their is a better and more efficient way to do it however (i.e. treating the front and back wall in a specific way?) Thanks again for all the time that everyone has spent thinking about this, I am buying all the beer in Albuquerque.

Colin, > If there are specific placements that are recommended, specific products, projects of the DIY sort, etc. that can be passed on to me. < There's a ton of information here in this forum, and plenty more on my company's web site. Part of the "fun" of DIY is figuring out what's needed. :) Seriously, I've already written explanations of everything you are asking, so if you'd rather find it all in one convenient place rather than search through posts and other info here, find the Articles page on our site. Also see the Placing MiniTraps page in the How To section which explains in detail where traps should go etc. Even if you plan to DIY your own treatment, all the advice there still applies. --Ethan