Basement Studio - Wall construction question

Have been researching for a while and have designed a studio to be built in my basement, and am ready (I think) to start purchasing materials. My goal is to build the best room I can, for monitoring mixes and tracking vocals - all other tracking is direct. Isolation is NOT a concern. I provide the following to help simplify any response (although, I'll always welcome add'l suggestions)... I feel fairly well informed in ratios, placement and types of absorption material, construction techniques, etc - my primary concern (and question) involves maintaining symmetry via wall materials, with an option for add'l bass absorption with the build. I'm a complete novice in smartdraw (my written plans are better detailed), so here is some additional image info: * Room size 21'3" x 14' x 9'8" * The black lines are 8'8" tall poured concrete walls that have a brick pattern. * The ceiling(upstairs floor) is 9'8" from the floor and underneath it are 12" I-joists running the length of the room 16" on center. * The green wall is a 2"x6" framed support wall, that I plan to mount drywall to on one side (haven't decided which side yet). * 4' from the front (blue line), running under the I-joists is a 3"x14" wooden support. * In the back is a 12"t x 30"w vent, 3/4 across the way * The 2 existing windows are 22"t x 34"x, the top falls just under the bottom of the I-joists. * The red line is the wall to be built. * NOTE - the external space both in the basement and above is fairly large. I plan on building a 2"x4" wood studded wall 16" or 24" on center, with a window mirroring that of the cement side wall, and a door opening outwards far enough away from the back wall for a corner bass trap. The inside of this wall would be drywalled with a brick textured wood panel(for looks and matching texture) on top of it - the outside of the wall would be left alone. Just short of building a brick wall, I know I can't fully mimic cement, but my thinking regarding symmetry is that any deviation for mid/highs between the new wall and the cement one could be controlled with adequate absorption treatment, and bass (being omni-directional) is not a concern and I may benefit some by it freely escaping thru the 2 walls and ceiling. 1: Is my thinking majorly flawed, and if so... suggestions ? 2: Just read the article on wood membrane bass traps - I don't expect details (I imagine its extrememly involved), but could I theoretically turn this wall (panel on inside, drywall on the other with inner treatment and sealant) into a bass trap itself by experimenting during the build, or might I create some drum-like problem ? Any comments welcomed. Dean

you could build inside-out walls (slats-cloth-frame-drywall) all around and this would give you a start with the treatments and isolation. overhead you could bolster up between the i-joists with drywall and add a ceiling below attached with resilient channel on the i-joists. a second set of windows - although you should probably look into egress requirements for a habitable space as the existing windows seem small. and if you're considering inside-out walls as an option to balance the space, you could take the next step to angle things...

Cool design, and I appreciate the time on it, but too involved for me at this time. I need to do most of the work myself and a chronic neck injury forces me to keep it simple and as 'light' as possible for now (I plan on putting alot of time and money into fiberglass panels, and help with a few sheets of drywall is available, but anything beyond would be too much) - I'm chomping at the bit to get out of my 9' cube. I really just want to know if my wall construction (design - drywall/panel etc.) is severely flawed, and if there's a better method of building it - again, isolation is not a concern - I'm mainly concerned with symmetry. Thanks again.

Aloha and welcome to the forum, What may seem to be an easy question, oftentimes does not have and easy answer. Perhaps a little reading might help to understand some of the factors involved. http://www.saecollege.de/reference_material/index.html (Be sure to click on the "acoustics" and "absorbers" tabs on the left and those that show up on the top) DIY Wall Units - http://www.johnlsayers.com/HR/index1.htm Home Recording Studio: Build it Like the Pros (Paperback) by Rod Gervais http://www.johnlsayers.com/phpBB2/viewtopic.php?t=5670 Hope these help, Aloha 8)

Thanks for the fast response and the new references. I actually just finished the Rod Gervais book, and before that "Acoustic Design for the Home Studio' by Mitch Gallagher - which I'm reviewing again. http://www.ethanwiner.com/acoustics.html I also found to be a great article, and prompted a visit to this website, as well as the 'panel trap' question. Rods book was very informative but concentrated very heavily on isolation, which again, is not an issue for me. My understanding from all my research is the ideal build in my situation, involves a 2-leaf wall system all around, for both isolation and symmetry - but as the need for isolation lessens, so can the build. Another way to pose the question (and where my research falls short) is when does a lesser wall sytem up against a basement wall become more of a detriment (as a floating a floor without a sand base does) than no wall at all ? My best guess thus far is doing what I've proposed, for the reasons given. Maybe I've overlooked something and I'll definetely check out the additional references you've given - but any opinion (or experience) with my situation is very welcomed. Either way, it'll be better than where I'm at now (a 9' cube), but if I can change something simple to improve it initially - I'll do it or at least strongly consider it. Thanks again Gullfo for the design, you also replied in another forum - everything I plan on doing now can be altered at a late date so I have noted it. Thanks again for the references. Dean

maybe consider building some moveable slat resonator panels to put some symmetry on either side of the desk and some absorbers around to reduce reflections. overhead a cloud with some reflective qualities angled to help reduce reflections at the mix position.

gullfo wrote:

maybe consider building some moveable slat resonator panels to put some symmetry on either side of the desk and some absorbers around to reduce reflections. overhead a cloud with some reflective qualities angled to help reduce reflections at the mix position.

Hey Gullfo, would you mind uploading some of the plugins you use for creating these? Thanks. I am thinking of making portable slat resonators as well just don't fully understand it yet. But I'm researching.

A couple of questions on this - given my room as shown, would you place this assembly up against the front wall (which would cut off the window (which is fine if it helps) or would you move it back away some or could that create other issues ? Again, your design with slats is more than I can do at this time, but it is very close to what I plan on doing by placing or hanging 703/705 panels ( or something similar). In playing with the monitor/listening position triangle using certain rules I've read (mainly the listening position being 38% back) it places my monitors near or under the wooden support - I plan on treating accordingly after the build, but your opinion of placement of your design could help me with this. Very cool set-up BTW. 8) Thanks, Dean

the idea here is "space coupling" where the sound is passing out the top and bottom or through the slats into the rest of the space. potentially this can be good or bad depending on the rest of the room charactistics but generally speaking the backing insulation should keep things mostly correct within the listening space... to really build up a set of resonators you'd want to build cabinets to create the chambers etc. my own space is (going to be) configured in a similar fashion to this but I also have 14' high ceilings and a very fragmented and angled set of walls and ceilings (in a 18'x26' room) which by themselves do all kinds of defraction... so I may get away with this approach... :-) I would leave a gap between the front of these and the wall (essentially in line with the back of the monitors on stands) so that sound can escape around the back of the panels. again, we're dealing with an open space so the escape allows the bass to move out. the front of the cloud would be just under the large beam and the monitors would be just under it so the space above and behind them (that 4' section behind the beam) could be bass trapping on the ceiling. you may still need some absorption up front but you can play with that. maybe just a drape over the window.

I am thinking of making portable slat resonators as well just don't fully understand it yet. But I'm researching.

check on John's design on the Moshwitz design thread. as far as plugins, this is hand drawn although i'm working on some Ruby scripts to hopefully automate slat/slot/depth/etc drawing... meanwhile I just use the various helmholtz tools to give me %, etc... to estimate the designs.

Cool - Makes sense. I'm going to look more into slats - I was only aware of the kind that require a sealed box (back and sides) thus requiring some heavy lifting. I have an idea of where I'm going to start with with absorption, but I plan on experimenting - this gives me more to look into and maybe play with. Thanks again !