20' x 25' Garage Design - Please have a look!

Hello everyone, I just want to say that this is such an amazing forum with so many knowledgeable, helpful and inspiring people, you guys are truly great! I have been scouring the site off and on for years and have utilized a great deal of your advice/techniques in previous studio renos and projects but had never joined as I didn't have any new builds or designs on the go... Having said that, my situation has changed as I have had to give up my old recording space so I am starting to design a new studio on my property in my detached 2 car garage (it is a shell right now, studs and trusses). I have attached my sketchup of the building with an initial 3 room design, (wall framing only at this stage) and I would love to get some input from you guys, specifically on my control room size/design, outer-leaf approach for maximum STC (given that I'm really trying to maximize my limited space, air-gaps aren't as substantial as they should be perhaps...) The Live room will have drums, guitar amps etc.. so I am looking at putting in the work to isolate these rooms from the outside world as much as possible (I'm hoping that I can go with serious mass on the 1st outer leaf (3 layers maybe 5/8 ply, 7/16 ply, then 3/4 MDF all sealed / glued to the outer studs) Anyways, I have lots of ideas, a few obstacles a couple of hurdles and many questions so please don't hesitate to throw some critique/suggestion my way, I will certainly be grateful for any and all input and will provide much more detail upon request. Thanks for your time, Sincerely Lee Billwiller EP Studios

looks like a good plan - maybe a small window into the isolation booth from the CR? also, plan on using built in soffits instead of the cabinets (unless you have them already) so you can use that additional space in them for bass trapping etc. same on the back wall, plenty of bass trapping and some large angled clouds across the front and top of the CR to bring it in. in the live room - break out the corners with angled slats for broadband absorption, diffusiveness, and reducing the corner. some polys would be nice, some slat boxes would be a nice touch, on the ceiling scattered absorbers to break it up. in the isolation booth - slats across that deep corner in back and scattered absorption to finish it.

Great, thanks for the advice and encouragement. I have done a little searching but was wondering how I should design the soffits for this particular control room. My flanking walls are angled at 12.4 degrees, is there a formula for calculating the size of soffit, and appropriate angles? I read about the 30 degree angling of the monitors in relation to the listening position (sweet spot) but I guess other factors come in to play (like speaker size/response) height of the front wall etc. I also want to use my Alesis A1's for nearfields and have a bigger speaker in the soffits for fullrange reproduction (i.e. mastering) Has anyone here heard the Hawthorne Audio Silver Iris Open Baffle Speakers? http://www.hawthorneaudio.com/catalogs/index.php?main_page=product_info&cPath=3&products_id=4 My friend has a pair of them with the matching Augie subs and I currently use his room for mastering, the speakers sound phenomenal and I was wondering if the soffit would work as an open baffle for these drivers? Any thoughts? Thanks again, Lee

plan on using 30 degrees for the soffit angle (creating a triangle). you could build your own monitors with the soffits effectively acting as the speaker box (in fact that's basically their intent anyways and may top studios use custom built or customized configurations instead of simply using stock speakers). for the most part using standard angles for the soffits like 30 or 45 is best because people are used to it, but sometimes you have to use other angles to accommodate the circumstances: 22.5, 36, 50 etc. are options when necessary, and even oddly defined numbers like 33.7 (example) when you really cannot make it work otherwise.

Glenn, Thanks for replying so promptly. Here is a pic of the soffits (at 30 degrees) with the points of intersect at the listening postion. With this angle it is putting me at about 41% into the room (a little more than the suggested 38%) what do you think of the angles and how they are hitting the back corners?? (of course I will have corner traps wall to ceiling as well as some diffusion at the 1st reflection points...) And do you think the position of the window into the live room will have any negative effects at this point? (in my previous studio I had a window at the 1st reflection point and built an insert, mirrored on the opposite wall to correct it while mixing, so I could do something similar if needed here.) Anyways, let me know what you think... Cheers, Lee

that looks pretty good, and 41% is no problem. you'll be tweaking that spot once you start working out the desk details etc. the window should be fine jut remember you'll want some absorption on the opposite wall and perhaps a very heavy drape to pull over the window when you don't need it. the back wall will have a bunch of trapping.

Hi Lee, Glen is much more knowledgeable than me regarding design so I will leave that to him. I have open baffle speakers in my living room (old alon 2, open baffle mid & high, sealed woofer ) and I would be surprised if they would function well built into a soffit. That's not how the design works. Where in BC are you? I'm building a garage studio in Surrey right now. You're welcome to come and look. Steve

Hey Steve, Yeah, thanks for that. I looked into it a little more and of course the "open baffle" design will not work in a soffit, nor would I actually want to use those specific speakers for critical listening (they are designed to make recorded music sound good as opposed to revealing source issues etc...) I am actually looking at some ATC clones made by a company in England, Wimslow Audio. They use ATC drivers, and Scanspeak tweeters in custom enclosures... Not cheap but a fraction of the price of comparable speakers! I am in Nanaimo, (Surrey By The Sea... as some people call it!) :P What a wet X-mas we've had... How far along is your build? Lee

Hi Lee, I'm building it one room at a time. So far I have finished the washroom, mostly finished the break room, just finished painting the control room and about to start some treatment and flooring. My thread is here http://www.johnlsayers.com/phpBB2/viewtopic.php?f=2&t=12308 but I haven't updated it for a while. I will keep my eye on your thread here and help where I can. Yes, rain and more rain.... and I just got a bicycle for Christmas! Happy holidays to you and yours! Steve

epstudio wrote:

I also want to use my Alesis A1's for nearfields and have a bigger speaker in the soffits for fullrange reproduction (i.e. mastering) Has anyone here heard the Hawthorne Audio Silver Iris Open Baffle Speakers? http://www.hawthorneaudio.com/catalogs/index.php?main_page=product_info&cPath=3&products_id=4 My friend has a pair of them with the matching Augie subs and I currently use his room for mastering, the speakers sound phenomenal and I was wondering if the soffit would work as an open baffle for these drivers? Any thoughts?

missed this. you want front ported or sealed speakers for soffit mounting. in some cases some back ported monitors can be used. an open backed monitor would not be effective in this role.

Hi Glen, Yeah, thanks for that. As I was telling Steve, (2 posts above...) I of course did some quick research and determined that I would NOT be using Open Baffle speakers in my soffits :oops: as they are not at all designed to work this way! But I am looking at getting a pair of ATC clones from Wimslow Audio in England. Exceptional speaker components at an affordable price (sort of) :wink: I will have updated design drawings and questions for you soon! Thanks again for keeping an eye on my thread, your input is greatly appreciated. Cheers! Lee

Hey Glenn, Here is my updated .skp file with my ceiling design. Please have a look and let me know what you think... ( I know this type of design has been talked about before and usually discouraged because of the extra labour / potential loss in isolation, however I really want the extra room height and I believe I can make this work...!!! ) :roll: I can explain my concepts in more detail once you have had a look... Any questions or critique, please fire away!! Thanks, Lee

assuming you are making the angled walls in the CR the isolation walls, i'd move the soffit and center absorber into the room further to allow more trapping. if the angled walls are not isolation (or at least the left wall) then you should have enough space. i'd add a small window from the CR into the booth.

Ok, so does that mean you think my roof design will work? Specifically, the way I am mounting the RC-2 and hanging the 2 layers of 5/8 Gyprock? (I realize in the sketchup I only did the back corner, but the concept would apply to the whole ceiling, control room included... " if the angled walls are not isolation (or at least the left wall) then you should have enough space." Enough space for what? I guess I'm not really following...

i think the ceiling is problematic as the interior truss members are going to be hit with sound and then transferring that directly to your roof. typically you want to re-do the trusses with the cross bracing up higher so you can seal the entire ceiling. to improve the isolation, use isolation clips and hat channel instead of the RC. are you looking to extend this over the CR as well or just use a flat ceiling there? if the left hand wall (as shown in your SU file) is not an isolation wall, then that space in the corner could be used for trapping.

Hi Glenn, Thanks. Yes, I was thinking the same thing over the CR (and then hanging clouds over the mix position to bring it in and get rid of parallel reflections at a 12 degree angle with extra bass trapping above the mix clouds) but NOT having the two ceilings touch (i.e. Hat Clips and channel spanning the length of the building but the Gyprock would not join the two ceilings... having each ceiling form an acoustic seal to it's respective room walls) Again, I don't have the option of removing and rebuilding the trusses, but I was planning on putting an extra layer of mass (3/4" OSB) on the roof and replacing the existing standard shingles with a more acoustically deadening roofing system... I could also put some dampening on all of the truss bracing to minimize the penetration of sound waves, maybe 1/4" neoprene? Would that be a waste of time and money? (Bearing in mind I would religiously seal around each truss that protrudes through the gyprock (with 1/8"-1/4" air-gap, backing rod and acoustic sealant) to ensure there is no flanking path from the trusses to the gyprock... So you mean behind the left soffit (in the space between the outer leaf and the inner leaf) using that for bass trapping as well as behind the soffit? even though the mirrored soffit won't have the extra bass trapping? If that were the case would it be better to straighten the live room wall (behind the Iso Booth) to have the same extra trapping potential as the left wall? so the bass trapping behind both soffits would have equal potential?

if you could straighten the right wall to mirror the left wall for trapping that would be good. then shift the isolation booth into the live room a bit to accommodate. i'd skip the neoprene on the trusses as i don't think it will add much. you might dress up the trusses with rigid insulation and cover with cloth to form baffles which could help with your absorption. hang plywood/MDF panels (perhaps with LED lighting) on angles (side-to-side, front-to-back, alternating?) in between each pair of trusses to break things up. make superchunk absorption in the peaks. something similar in the CR except angle the plates down in the front up in the back to mimic the overall roof angle (slightly less steep).

Interesting... So, this is in conjunction with my existing ceiling plan? ( using RISC1 Clips and Hat Channel to hang 2 layers 5/8" Gyprock for the inner leaf of the roof...) And do you agree I should add mass to the outer leaf of the roof and install a better shingle system? Thanks so much for your help Glenn, I really appreciate your info.

yes, add the mass, yes go with your plan (understanding the flanking potential to reduce your TL) and then conceptually use this last idea to dampen the truss vibrations, add absorption, and some acoustic and visual interest to your open ceiling space.

Are you going to use a vented or sealed roof system? Steve

Hey Steve, After much consideration (and potential pain in the :cen: with non-vented) I have decided to use a vented roof system with full ridge and soffit venting... I figure because of the extra mass I am going to have on the roof and my ceiling plan, I don't think I will hear the rain! (which is my main concern...) What did you do?

Hey Glenn, Is this what you were talking about for extra bass trapping behind the angled CR walls? (essentially a couple of huge superchunks...) Also, I threw in some simple slat absorbers on both walls, is this a good idea or would you suggest something else... (thinking that they would vent through to those extra absorbers behind the walls...) Thanks.

Typically you see many designs where the soffit space is open in back with a port on the bottom of the soffits faces and used for the bass trapping and the side walls are slats or membrane absorbers which have sealed cavities (as the space narrows and is less useful for bass trapping).

Ok, so does that mean I should pursue this design, or should I straighten the CR walls and build the bass trapping and angled walls together using sealed cavity slats/membranes?? :? Sorry to ask, but I am not sure how to proceed to get the best response out of this room especially as I have never built soffits before... And in reference to your earlier post's: "if you could straighten the right wall to mirror the left wall for trapping that would be good. then shift the isolation booth into the live room a bit to accommodate." This is what I did in the last pic. "if the left hand wall (as shown in your SU file) is not an isolation wall, then that space in the corner could be used for trapping." The left hand wall is an isolation wall (I believe??) as my exterior wall is just to the left of it and my design is typical MAM, so I guess I just need a little more explanation/direction with all of this if that makes any sense!! Cheers!

I did a sealed roof system. I sprayed the underside of the roof with 2lb closed cell foam. I didn't want to destroy the the integrity of my outside leaf with venting. A caveat though, I work in the business so my opinion is biased and my install price was low. Steve