Design for my long one-car garage

Well, I was out of town, and when I got back, my job took over my life. Anyway, I’m back with another revision. I’ve decided to just focus on the control room for now; once I’ve got that figured out, the live room should fall into place. Thanks to Stuart’s advice, I’ve tweaked the angles in the room. Since my soffits are at 38°, I’ve set my walls at 7.62 °. I came to this number using a little algebra: 12°/30° = x°/38°. This is how I came up with 15.24°, or 7.62° for each wall. As I mentioned in my introduction, math is not my strong suit, so if anyone sees any holes in my logic, please let me know, and I’ll go back to the drawing board. Using my new angles, I set the ceiling to 15.24° up to the halfway point of the room, behind my listening position, then I leveled it off a bit to 7.62°. I did not have room to maintain the 15.24° across the length of the room, so hopefully this is a good compromise (right, Stuart?). The new angles give me the following room dimensions: Height (inside-out ceiling) Front wall: 66.25” Middle of room: 92.75” Back wall: 100.5” Width (inside-out walls) Front wall: 85” Back wall: 115 ½” Length (inside-out walls): 121” If I take the average ceiling height, I come up with 88,” and the average width is 100.25.” That gives me a room ratio of 88: 100.25: 121, or 1: 1.14: 1.38—almost exactly Sepmeyer’s first ratio. One big caveat, which is beyond my mathematical ability to figure out: the room is obviously smaller in all three dimensions toward the front of the room than in the back, and so I would imagine that affects how well it fits into this model. In other words, I’m taking averages to figure my room dimensions for width and height, but since I’m sloping the ceiling, the volume of the front of the room is not proportionately the same as the back. Should I be concerned about this, or am I splitting hairs? I’ve got the listening position close to 38%, and I’m shooting to have the tweeters hitting my ears at my normal sitting height of about 47.” With a front wall height of 66.25,” that puts the woofers at about 40” or so. From what I’ve read, this seems to be a good relationship between the speaker height and room height. Am I right? Finally, on a more general note, I’ve laid out these dimensions in a “real” room to try to get an idea how it will feel once it’s completed. It’s definitely small, but workable, I think. The way I’ve approached this design is to try to focus on getting a good room ratio using inside-out wall construction. This seems to be the only way I can hope to end up with a good sounding, albeit small, control room. I’ve seen designs for small rooms like mine that don’t slope the ceiling at all, and I wonder if I’m missing something. Perhaps the people designing those studios decided that they were personally more comfortable with the added headroom they get when they don’t slope the ceiling, or perhaps when you get a room as small as mine you get to the point of diminishing returns. In other words, is there a point where the room gets so small that it’s better to have bigger dimensions even if you don’t angle the ceiling? Just thinking out loud. Thank you for any input, everyone!! Mark

Mark - you are wasting the space behind the splayed walls

"If I take the average ceiling height, I come up with 88,” and the average width is 100.25." Averaging is guessing. The ratios established were in rectangular rooms with known boundaries so all standing waves and frequency issues are based on those measurements. When you modify a rooms dimensions with splayed walls none of the ratios work in that respect. As a starting place for a room's walls, yes, this is a better place than guessing. But beyond that, it's a completely different room now.

Hi John-- Thanks for the reply. I understand your point, and have seen you mention this to other people regarding their designs. However, I don't know that I'm really wasting that much space. Perhaps I should have posted more pictures in my last post. I'm attaching an image from an earlier post that gives a better "big picture" of what I'm after. In my case, the only wasted space is to the left of the control room--the LR wall parallels the CR wall. The space to the right of the LR is storage. The yellow triangles in the back of the CR are bass traps. It seems that when splaying walls, some wasted space is inevitable, however, If I'm missing a better approach to my limited space, please let me know; I really appreciate your input! Thanks, Mark

Hi xSpace-- Thank you for your reply, too. I have wondered about this issue all along as I've been reading about room ratios. I'm not sure how to address the problem, however. How does one calculate ratios in a room with splayed walls if averaging is not an option? Given the number of rooms with splayed walls on this site, I'm guessing there's a solution. Or perhaps everyone is guessing until they've actually built the room and run tests? In my case, I have two dimensions that cannot be changed: I have a maximum length of 121" and a maximum height of 100" or so. I've used what I've thought were good angles for splaying the walls and ceiling, so I guess I'm not sure where to go from here. Is there some other way I should be approaching this, or are you just pointing out that since my room is not rectangular I cannot apply any of these room ratios with any real confidence? I've developed several different designs for the space I have to work with, and I was thinking that my most recent one is getting close to the best I can do with my space, but now I'm not sure. If there's something I haven't thought of, please let me know. I really want to design this as well as I can. Thanks for all your help! Mark

Hi Mark - Yeah - I haven't followed your earlier posts so thank you for updating me - my comment still applies to the left side of your control room. the extra depth lowers the slot resonator frequencies which is well worth exploiting.

Bigsby wrote:

Hi xSpace-- How does one calculate ratios in a room with splayed walls if averaging is not an option? Given the number of rooms with splayed walls on this site, I'm guessing there's a solution. Or perhaps everyone is guessing until they've actually built the room and run tests? Thanks for all your help! Mark

That's about it. Develop (if at all possible) a room footprint based on good ratios then proceed from there. You break up the wall plane when you splay which translates to room diffusion. This action (splaying) if done correctly will eliminate paralleled walls which produce flutter echo. So the benefits are gained immediately :) Then you have to test...you should test it at every stage really. From nothing to something to know where you are when you start to have a base line to work with towards the end of the build.

Thanks, guys. I really appreciate your input; it's invaluable. So xSpace, it sounds like you're saying I'm on the right track, but that I just need to proceed knowing that I can't predict at this point what sort of issues I'm going to have as I build the room. I'm thinking that some of this can be addressed by building my resonators and traps specifically for my room, trying to compensate for modal problems that I discover when testing, is that correct? And John, could you give me a little clarification, please:

my comment still applies to the left side of your control room. the extra depth lowers the slot resonator frequencies which is well worth exploiting.

Are you saying here that I should make the left side of the inner leaf of my control room straight, and then angle the resonator as I've pictured in my design to accomplish this? If I do this should I not build the right wall the same way so that the left and right walls are the same? I'd prefer to keep the right wall the way it is, giving me a splayed wall in the live room (not to mention a little more precious space in the live room, as well!) but if I'm better off basing the control room on a rectangular design and then splaying the resonators on both sides, then I'll do that. One last thing, more generally speaking: does this control room appear workable? Is it big enough that, with proper treatment I can expect to like what I hear? Thank you! Mark

Yes - what you said Mark - it doesn't matter that the two side walls are different as their fronts are the same and that's what matters.

Thank you, John. That's what I'll do then. I'm sure I'll have more questions when it comes to actually designing the resonators. Getting back to my most basic question: does this control room appear workable? Is it big enough that, with proper treatment I can expect to like what I hear? I guess my biggest concern on this topic is the ceiling height: Is it worth the volume in the room that I lose in order to angle the ceiling the way I'm doing? I'm inclined to say "yes," but I see quite a few small room designs that don't bother angling the ceiling. Just to refresh your memory, below are the dimensions from my earlier post: "I’ve tweaked the angles in the room. Since my soffits are at 38°, I’ve set my walls at 7.62 °. I came to this number using a little algebra: 12°/30° = x°/38°. This is how I came up with 15.24°, or 7.62° for each wall. As I mentioned in my introduction, math is not my strong suit, so if anyone sees any holes in my logic, please let me know, and I’ll go back to the drawing board. "Using my new angles, I set the ceiling to 15.24° up to the halfway point of the room, behind my listening position, then I leveled it off a bit to 7.62°. I did not have room to maintain the 15.24° across the length of the room, so hopefully this is a good compromise (right, Stuart?). "The new angles give me the following room dimensions: Height (inside-out ceiling) Front wall: 66.25” Middle of room: 92.75” Back wall: 100.5” Width (inside-out walls) Front wall: 85” Back wall: 115 ½” Length (inside-out walls): 121” " Thanks so much for your help! Mark

Hi-- I'm hoping one of you can reply to my last post. I've gotten great guidance along the way as I refine my design, but I'm still a bit insecure about the most basic question: will it work o.k. given the dimensions? Should I assume that silence means tacit approval? I will soon be at the point where I begin making construction decisions based on my design, and I don't want to start off on the wrong foot :shock: As always, thank you for your input! Mark

"I guess my biggest concern on this topic is the ceiling height: Is it worth the volume in the room that I lose in order to angle the ceiling the way I'm doing? I'm inclined to say "yes," " I would keep the room volume, it is worth it. Thing is if you leave it and have to add an overhead cloud, you still have room. But if you remove the height...it is difficult to get back. 12 degree (total)is all I have seen suggested for splayed walls. So if you do this to the ceiling you start at the highest position available to keep as much room height as possible.

Thanks, Brien-- So, just to clarify, you're recommending that I do not angle the ceiling, instead keeping it parallel to the floor, thus maximizing my height (and room volume). This would throw off my room ratio, but, as you said in an earlier post, those ratios are based on rectangular-shaped rooms. So really, I'm only guessing anyway when I try to apply them to a room with splayed walls. In this scenario, like you suggested, I should expect to add a cloud over the listening position, thus mitigating flutter between the floor and ceiling. If I'm going to do that, do I still need to build the ceiling inside-out? Thank you! Mark

Start from the highest position possible as dictated by the room and slope the ceiling 12 degrees if possible. Or not. If your ceiling height is high enough you can install a cloud and slope the cloud. Or not. The largest volume you can get out of the room gives you room to treat if needed and reduce. If the room is already reduced and you need to treat...it gets even smaller. Are you talking about both rooms, the control room and/or the tracking room? I do not recall immediately an inside out ceiling that really needed to be constructed when the boundary could either be sloped or a cloud could be installed to reduce the hard boundary potential for flutter. I would get the maximum amount of mass I could in the ceiling area, maximum height and maximum mass. This is the place that most external sound gets into from the building venting and overhead airborne sounds.

Great--Thanks, Brien. I think I'll go ahead and build the ceiling flat and not inside-out. Done that way, I will have about 8' of height. I was concerned with how cramped the room would feel when I angled the ceiling (5'6" at the front wall, , so I'm glad I asked. As you say, I will then have room to treat the ceiling, but if I angle it and it still needs treatment, I won't have any more room for that. As far as the tracking room goes, I still want to explore the idea of converting the existing structure to scissors trusses so that I could vault the ceiling. I'll need to talk to an architect/engineer about the practicality of that, though. I decided to nail down the exact design of the control room first, as I keep making adjustments to it that affect the live room. Now that I have a design that I think I will go with for the CR (unless someone tells me I shouldn't), I'll finish the design on the LR. Thanks again for your help; I really appreciate it! Mark

It may not be the best help but it is the best help I can produce on such short notice. ;)

Well, I'm on the home stretch of the initial design phase (I hope!!!) The following design is what I will use to begin my build, unless someone says "No!! you fool!!!" :lol: As a refresher, here are my dimensions: Since my soffits are at 38°, I’ve splayed my walls to 7.62 °. The new angles give me the following room dimensions: Height (normally-built ceiling--not inside-out): 95" Width (inside-out walls) Front wall: 85” Back wall: 115 ½” Length (inside-out walls): 121” With advice from xSpace, I've decided to build the CR ceiling normally, and make it flat, for maximum height, and install a large cloud sloped at 12 degrees over my listening position to take care of the potential for flutter. I'm still willing to build the ceiling inside-out, but I feel that if I angle it will just make the room feel too cramped. For the LR, I'm really thinking of converting to scissors trusses and vaulting the ceiling as much as possible. Still talking with my architect friend about the practicality of that idea. The wall next to the CR will be splayed by 7.62 degrees, and the opposite wall of the LR will be the mirror-image of that. I'm planning on building slot resonators as pictured along one wall, with the opposite wall being cloth-covered and inside-out. The "wall" directly to the left of the listening position will not have a leaf attached to it; it will be there only to support the slats; the real inner leaf is behind it, parallel with the outer wall of the building. I made this adjustment in response to John's advice that deeper cavity behind the slats could help take care of low frequencies. Please tell me, John, if I am approaching this aspect correctly. Well, I think that's it. I can't wait to get started...or not, if I still need to refine this.... As always, thanks so much for your input, Mark