Confusion about wall angles. SAE VS This forum

Greetings all, and thank you for this fatastic forum. I've been visiting you for quite some time now. However, so as not to be forthrightly admonished, I have been reading rather than posting. With so few posts under my belt (0) :) . , I hope this one doesn't seem trivial. Ive tried to avoid posting before exhausting all the search options and the mountains of reference material you've all so generously given to the world. Of hundreds brought, I haven't been able to answer one question. If I've just missed the answer its not for lack of trying to find it. Appologies in advance. And the question: In a control room, should the angles of the side walls be 6 degrees or 12 degrees from square? The http://www.saecollege.de/reference_material/index.html SAE digrams (control room) say 6 degrees, but I've seen posts in this forum that refer to 12 degree walls. According to the SAE reference "the angles are what make it work", I'd like to get it right. I've been preparing for my own basement studio build and hope to share it with this forum when I can get it together. It seems I still have alot to learn. Thanks again, I look forward to hearing your thoughts.

12 degrees is the recommended angle to stop direct standing waves from forming - the minimum would be two walls at 6 degrees which makes 12 degrees overall. The 6 degree wall design is for control rooms where space is a limiting factor, 12 is better if you can fit it in. ;) cheers john

Hey, In my studies and general internet surfing over the past 10 years, I've found that there is alot of conflicting info on design. For example: -Until finding this forum I read that the control room should face the long wall. Most comercial studios I've worked in are like this too. Not sure if thats because the size of studios has decreased considerably. Ware houses down to double garages :D -THat soffits should be solid cement. (was that you Ethan) -Reflective back wall /absorbent back wall/absorption behind non-soffit mount speakers...........blah blah? I think all ideas can work in the the right environment and every-one has there opinion. Thats what's so great about audio... it's 50% science 50% art. I've got a great skp design of a soap box if ya interested :wink:

The 6 degree wall design is for control rooms where space is a limiting factor, 12 is better if you can fit it in.

Thank you for answering, so quickly John. Now I know that 12 is best, but that begs another question. Is it 6 or 12 or would one benefit from maximizing the angle between themm, within the constraints of the room size of course? ie., is 8.5 degrees better than six?

Thats what's so great about audio... it's 50% science 50% art

I wholeheartedly disagree, envy... it's 49% science and 51% art :P So there...

lilith_envy wrote:

Hey, In my studies and general internet surfing over the past 10 years, I've found that there is alot of conflicting info on design. For example: -Until finding this forum I read that the control room should face the long wall. Most comercial studios I've worked in are like this too. Not sure if thats because the size of studios has decreased considerably. Ware houses down to double garages :D

Not the studios I've studied. It nay appear that way when you don't take into consideration of how deep the back wall is behind the treatment.

-THat soffits should be solid cement. (was that you Ethan)

That's been bandied around, it's more a "may be" than a "should be".

-Reflective back wall /absorbent back wall/absorption behind non-soffit mount speakers...........blah blah?

depends entirely in the basic design and the room size. If the room design is LEDE then the front is absorbent and the rear reflective. This system hasn't taken on and only a few studios following that design these days. If its a small room with standard soffit mount the front is reflective and the rear absorption, BUT if it's big room and the rear wall is more than 9 - 10 feet from the listening position then it can be reflective. The rear reflection is typically something that is diffusive, it adds support to the high end response at the rear of the room.

I think all ideas can work in the the right environment and every-one has there opinion. Thats what's so great about audio... it's 50% science 50% art.

I think it's 100% Art because good science is an art.

I've got a great skp design of a soap box if ya interested :wink:

as you can see - so have I :D cheers john

Is it 6 or 12 or would one benefit from maximizing the angle between themm, within the constraints of the room size of course?

6 degres on each wall should be considered a minimum, if you can splay more than that, do so. so yes 8.5degres on each wall is better than 6degres. I splayed my side walls 15degres each but my room design is based on John's corner room studio so i don't loose much space. More than 15 degres just don't get you any better results. Hope this help

8.5degres on each wall is better than 6degres

Thank you Orangenumerik for your input. That will help me move forward. And again, thanks to John, the moderators and all members of this most excellent forum.

hey, John Says-"Not the studios I've studied. It may appear that way when you don't take into consideration of how deep the back wall is behind the treatment" So in music farm, is it a trick of the camera, or does the wall continue behind the couch/treatment. Little fish studios in melbourne is similiar to music farm and I'd almost bet it's wider than long?? Behind the back wall was the machine room, not much hiden space.

Wall angles will not prevent standing waves...they will prevent flutter echo. Standing waves, are just teh natural frequencies at which anything resonates/vibrates, and all rooms will have them no matter what. Non-rectangular rooms will have less predictable standing waves than rectangular ones, but they will still have them. Short story...non-parallel walls do not reduce the requirement for bass trapping, they jsut reduce the requirement to handle the high frequency flutter issues. Cheers. Kris

Kris wrote:

Wall angles will not prevent standing waves

John wrote:

12 degrees is the recommended angle to stop direct standing waves from forming

Good advice is hard to come by. This website's namesake has my trust. Thank you again John.

So in music farm, is it a trick of the camera, or does the wall continue behind the couch/treatment.

no it doesn't go back further but this is the refurbished version of the control room which I wasn't involved in, (I only did the studio) - the original room had 2 feet of rear trapping - also the room was built in '79 - I would build it differently today. cheers john

11coco wrote:

Kris wrote:

Wall angles will not prevent standing waves

John wrote:

12 degrees is the recommended angle to stop direct standing waves from forming

Good advice is hard to come by. This website's namesake has my trust. Thank you again John.

You're welcome to beleive whatever you wish...however I'd suggest doing a little more research on standing waves. You'll see that there is no possible way that a change in room shape can prevent standing waves. Please don't take my word for it...maybe read some books by Alton Everest, he usually covers it. As analogy, take a thin peice of plywood cut into a rectangle, cantelever it and strike it. Notice it's resonate vibration mode. Now cut some material out of it...change it's shape. Strike it, and notice that it still vibrates in specific modes (ie. standing waves)...but they're just different than the rectangulat peice. Wall angles affect high frequency flutter...which is also easy to control with diffusion and absorbtion. Thinking that wall angles will reduce requirements to manage bass buildup (i.e trapping) is false economy. Cheers, Kris

Kris is correct - it stops flutter echoes between two parallel surfaces - As far as standing waves are concerned they do force the standing wave to form via a different path, but it still forms. yes - diffusors and absorbers can stop the flutter echoes but only from around 250hz up. You can easily check if your room has standing waves by listening to the bass while moving around the room. If you have standing waves the frequency response will change from strong bass to weak bass in different positions in the room. You are then standing in the nodes (boost) and antinodes ( weak ). If you have low end standing waves due to parallel walls covered with absorbers or diffusors you won't hear them like the high end flutter echoes, but they will be there. So you place a snare or kick mike right in a low end room antinode and wonder why there's no bottom end. In a good control room there should be no change in response and the bass should be even throughout the room. I've found that using around 12 degrees in the sides of my control rooms helps. cheers john

I think John that you'd agree that in order to get even bass response throughout a room that trapping of some sort will be required, regardless of the shape of the room. Angling the control room walls is a good idea if you can afford the space. It sure makes it easier to set up a RFZ at the main mix position. Bass trapping will still be necessary to prevent holes/peaks in the low freq response. Positioning of these traps will not be as straightforward as it would be in a rectangular room (because you can't determine analytically where the modes will terminate), but the usuall general rules will apply (e.g. corners will need extra trapping). Cheers, Kris

John wrote:

In a good control room there should be no change in response and the bass should be even throughout the room. I've found that using around 12 degrees in the sides of my control rooms helps.

Thanks again, John. I think that I will use the 12 degree technique in my design along with some of the trapping, diffusion, resonation and other methods described in this forum. Kris wrote:

Angling the control room walls is a good idea if you can afford the space. It sure makes it easier to set up a RFZ at the main mix position.

I hope to be able to accomodate the angles in my basement build, kris. I also intend to maximize the volume of bass trapping material. in the control room. I hope to post my preliminary designs in the next few days. Thank you for your input, Kris. I'll also take your advice and do some more research on "standing waves". :) Guidance, G.

No problem....knowledge is power! Looking forward to seeing your design. Cheers Kris

How does music farm sound john? Have you heard any mixes there? lil

lilith_envy wrote:

How does music farm sound john? Have you heard any mixes there? lil

I was chief engineer/producer there from 79 - 84, in that time Misex, Mondo Rock etc recorded there. So yes - I've heard many mixes there - it was a great sounding control room and studio. After the refurbishment in 95 I also recorded Olivia Newton John in that studio for her Gia album. cheers john

Here's the link to my basement sutdio build - design phase.http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8551 Hope to see you there. G.

Does it make any sense to angle the exposed face of acoustical treatments (absorbers) along the sides of your mix position, even if the walls behind aren't angled?

John Sayers wrote:

12 degrees is the recommended angle to stop direct standing waves from forming - the minimum would be two walls at 6 degrees which makes 12 degrees overall. The 6 degree wall design is for control rooms where space is a limiting factor, 12 is better if you can fit it in. ;) cheers john

So for angled ceilings what is the recomendation? 12 degrees?

eruss wrote:

So for angled ceilings what is the recomendation? 12 degrees?

yes