Basement Studio - Control Room Anatomy

First of all, thank you so much for the talent and experience of the folks on this forum, and their willingness to share their knowledge. I am very pleased that I now have a floor plan that meets the requirements for my basement studio. I have been working on this for some time now with the help of the folks in the design index of this forum (Thanks Glenn and John) I am now starting to determine the building material for each room. You can follow this link to my previous posts in the design index ( viewtopic.php?f=1&t=9776 ). The most difficult room for me to determine materials , is the control room. So I am going to start there. I have had so many versions of this plan, but recently while watching the forum I found a floor plan that seemed perfect for me. I cannot remember whose build it was. Anyway, I pretty much copied and pasted it into my layout, and it works just fine. My current challenge is to define the anatomy of the control room construction. It looks to me as though the designer had color coded a few things, but I am not sure I agree with what I think the color codes are referring to. I am attaching two diagrams. One is the one I have marked up with what material I believe should make up the control room. The other is a blank drawing. I hope that some one can copy and paste it in to their favorite graphic editor and make their comments on the anatomy of this room. Right off, I will state some facts about the room. I will have a door at the front of the control room with 5/8" thick glass for viewing into an Iso Booth. There will be a 3/4 Inch thick glass window to the right of the desk for viewing into the adjacent live room. The control room and all adjacent rooms will have room within a room construction, two layers of 5/8 drywall, and pink fluffy insulation against the outside of the drywall. Control room framing is separated from adjacent room framing by at least 3". Speakers will be soffit mounted. As you can see from the drawing I have labeled what I THINK should be used for various surfaces. I am not sure about some of them. As you can see with the soffit mount speakers there is drywall behind them and beside them. I do not know for sure if this cause leaf issue or not. I do want isolation behind the speakers to prevent bleed into another room. I am also not sure if the current trend for trapping in the rear of the room is still to use hangers. I know at one time that was the thing to do in the soffits. Now I see folks filling the soffit with bass trapping material, floor to ceiling (705 or similar, I assume). I believe some are doing that in the rear corners as well. Any preferences? The middle rear of the room looks to me like there is a reflective surface on angle hidden behind Fabric and an absorptive material. Anyone care to comment. Since this is not the first time this plan has been on the forum, I would appreciate it if someone who has used this plan successfully might respond with their interpretation. Thank you in advance for your assistance. Joe

Just a comment on the layout: To me it looks like your mix position is almost exactly at 50% of the room depth, from front to back. Why would you want to do that? Isn't that the worst possible position for listening?

Stuart Good observation. To improve the mix location (bring it closer to the front wall), the non-angled wall directly in front of the desk, and between the soffits must be reduced. This allows me to squeeze the speakers closer together, thus bringing the 60 degree crossover point closer to the front wall. I actually am doing this in my sketchup plans, but this jpg has all of the framing and material in it, so I did not want to re-do the drawing that someone had already spent allot of time on. OK, I'm lazy. Having said all that, there is unfortunately a limit to how small the space between the soffits can be because I have a 3ft door going there. So, while I can change the mix location to somewhere around 44%, I cannot approach the optimum 38% mixing location. As many folks have suggested on the forum, there is often a compromise to be made when considering visibility, room size, speaker placement etc. With the 12 degree angled walls, soffit mounting my speakers and sufficient diffusion in the rear, I think the room should be fine. If anyone has other opinions, please chime in. Stuart thanks for taking the time to critique the floor plan. Your input is valid and much appreciated. Thank you. Any ideas on the control room anatomy out there? Joe

There is an announcement at the top of the forum about what to do to assure getting as many responses as possible. The announcement leads to this post. Actually, several people, who are experts on this forum, will not reply if you do not do what is written in the post. Many others who are very helpful, will not reply out of respect for the moderators' wishes.

Hi Avare I am not sure what I have missed. Maybe you did not see my link in the first paragraph of this thread which takes you back to my design process ( viewtopic.php?f=1&t=9776 ), and lengthy intro ( viewtopic.php?t=4589&highlight=kurtz ). Glenn, Knightfly and others were responsive in the design process which started a few years ago and completed several months ago. Is there something else I have missed? Joe

jkurtz wrote:

I am not sure what I have missed.

The second post in the thread I linked is:

John Sayers wrote:

]May I add one important factor to Steve's requests. I frequently create a design for members only to be told, oh - that door only goes to the bathroom, or there's pole in the middle of this room I forgot to mention. Please, sit down and analyse your room totally before you post a plan and INCLUDE all the info on the room. I'll be much more inclined to pursue a great design with you if you do

In your previous post in this thread you wrote:

jkurtz wrote:

Having said all that, there is unfortunately a limit to how small the space between the soffits can be because I have a 3ft door going there.

Hey Joe. There is another thread here somewhere (trying using "search") with a discussion about the 60 degree angle for speakers. To summarize, John says that a 90 degree angle is also OK (although not ideal as it narrows your sweet spot), if you really have very tight space limitations. You might want to consider that. Angle your speakers more, to get 90 degrees instead of 60, and I think you'll find that everything else falls into place a bit better. And like Andre said, it would be REALLY helpful if you were to post a sketchup model / images / diagrams of your actual own room layout, with your real dimensions and limitations, so that people don't waste their time suggesting things that can't actually be done in your space. - Stuart -

OK, I will try again. Here is the updated version of my control room based on the diagram that I have been asking questions about. To see more detail of all of the rooms in the studio, just go to me link in the design section which is posted earlier in this thread. As I mentioned before, it is very similar to the diagram I posted in this thread. The placement of windows and doors are really irrelevant to my questions, which relate to materials, and placement as a whole. Stuart You seem really concerned about the 38% rule, which is off topic, but I will gladly go down that road if it eventually brings an answer to my questions posted at the beginning of this thread. I have also heard (as you have mentioned), that it is possible to go 90 degrees instead of 60 degrees. But for the reason you already stated (smaller sweet spot), I do not want to operate that way. I have done some searches on the 38% rule and plan to do some more. While I am aware of it, I have never felt it as important as room modes, splaying, absorption, isolation and diffusion. Most of my early sample Control Rooms were based on John's samples. I have posted pictures of one of those here. The mix position in his sketchup is exactly where my mix position is. So, while I am not yet convinced of the 38% rules relative importance based on the many control rooms that I have seen that did not follow that rule, I consider myself to be open minded and will do more research. I would also appreciate anyone else's comments on this. Please see John's sample studio below and notice the mix position. Thanks. Joe

The 38% rule is a guideline. 50% back is one of the worst possible positions. For more on the guideline read The 38% Rule from Wes Lachot. Andre

Andre Just curious. What do you make of the designs from John Sayers such as I have posted above where the LP is around 50%. John, please feel free to weigh in! I have read the thread you pointed me to, and want to read it one more time before I post my questions and concerns relative to that thread. I only wish I had received this much attention when I was on the design phase of my project. We might not be having this conversation. I spent so much time on this design, and finally got things where I like them, moved to the build section and immediately got challenged. Don't get me wrong, I LOVE IT! I believe it will provide a better studio, and I will feel better about the design when it is all said and done. Thanks. Joe

jkurtz wrote:

Just curious. What do you make of the designs from John Sayers such as I have posted above where the LP is around 50%.

I do not see the listening position at 50%. The monitors are aimed behind the LP. you have the LP at 50%, from what I see. Andre

Andre The picture labeled "forum post 11-22-08 #3.jpg [ 50.9 KiB |" is the one I am refering to. It is just one example of John's designs with the speakers pointing at the 50% position. The actual LP is obviously in the 40 to 45 position, as is the case with my design. Just to make sure I am clear on the terms. Isn't is OK to use LP interchangeably with Mix position? When refering to mix position, are you and Stuart refering to the actual position of the Mixing Engineer's head, or are you refering to the the apex of the 60 degree speaker directional triangle located behind the engineer's head? Thank you. Joe

12"in front of the apex or there abouts. LP and mix posution are the same. Andre

Well it has been a while since my last post. I had the holidays to deal with, and life in general. No excuses now. As suggested in a previous post, I spent a great deal of time reading the 38% rule, and must say I would be lying if I said I understood all of the graphs and formulas. This is obviously a very controversial topic, as many posts suggest. Seems the 38% is only a starting point, and that the actual prime LP could be less or more. That being said, I have tweaked my control room slightly so that the LP with my arms resting on the console (my usual position for mixing) is right on the 38% line. It creates a slight challenge with the door to the opposing ISO room, but nothing a floor mounted door stop cannot address. I decided not to go with the 90% angle for the speakers for the reasons previous suggested (shortened sweet spot). I believe the picture below provides enough detail for the basic floor plan, and positioning of furniture. I would appreciate any input relative to the control room at this point. Does the basic floor plan look OK now? Thank you all for your input. Joe

Sorry for the long break in posting. Thank you to all who have provided input. After the guidance I received to place my listening position at the 38% position, I realized that I was not going to have appropriate space between the control desk and the door leading into the small Iso booth, and moving the desk up to that position also gave changed my visibility to the large live room. At that point I just decided to take a break from the studio project for a while. It was summer time anyway, and lots to take care of around the house. I am back, and have been reviewing the forum for the last month or two. I recently came across a studio design from John Sayers that I had not seen. It gave me new inspiration. I believe applying this approach to my control room may be just what I was looking for. The studio I was looking at is called “Recording Oasis”. Basically the studio control room uses three glass panes in a Bay Window approach. Speakers are above the glass. See below: download/file.php?id=29412&mode=view By applying this design to my control room, I can spin the room back around, have great visibility into the large room, and good visibility into the side room. I do not show any doors yet in the control room. I just wanted to get the basic idea created. I am also trying to get used to Sketchup again. This design also lets me have plenty of room for my control desk and still maintain that 38% listening position. What do you think? My initial questions are as follows: - Any drawbacks to this type of design? - Is the Apex of the 60 degree triangle still one to two feet behind the listening position? - Should Tweeter of speaker be aimed at listening position - How are things affected by having the speakers facing on a downward angle towards the listener? I realize you cannot just move the listening position back and forth any more because the apex of the angle will be below and behind the ears, rather than on the same plane behind the ears. Thanks in advance for your input. Joe

Well, I am finally purchasing materials for my build. I purchased flooring for all of the rooms. Purchased 2x4 lumber to get started on the control room. I need to have some plumbing rerouted in the basement so that I can make full use of my ceiling space. I still am kicking around which approach is better for the control room. I am a little nervous about the control room "North facing" option, only because I have not seen one built like this on the forum. With the speakers above the glass, I can longer use the approach which is so well documented on this site for flush mounting speakers in a vertical plane. What I do like about the "North Facing" control room option is the flow of the studio, and the visibility. I just hope if I go this way that I do not have any issues with sound in the control room. After all, the main functions of the control room will be monitoring during tracking, and mixdown. And I don't want the mixdown quality to be substandard. I have posted a few pictures of my current "North facing" design showing the framing. I am trying to make my mistakes on paper, so to speak. So if any of you see things that don't seem right, please give me a shout. I will highly welcome confirmation of the design or constructive criticism. Thank you. PS: I would like to make the Sketchup file available. But it is quite large, and has many layers not shown. If anyone has a good inexpensive solution to recommend for sharing the file, I would appreciate the input. Thanks. Joe

Maybe it isn't really what it looks like on that picture, but is that a three-leaf wall there? It sure looks like one! If so, you will definitely want to fix that! Also, the angle of your speaker soffits looks to be way, way beyond the 10 degree maximum, and the speakers are not centered in the soffit panels. That's the two things that stick out. If you can post the SketchUp on one of the free hosting services, that would make it easier. - Stuart -

I'll see your 3 leaf and raise you a broken M/S/M!

Soundman2020 wrote:

Maybe it isn't really what it looks like on that picture, but is that a three-leaf wall there?

Not preserved: maybe-3-leaf-wall.jpg

It sure looks like one! If so, you will definitely want to fix that! Also, the angle of your speaker soffits looks to be way, way beyond the 10 degree maximum, and the speakers are not centered in the soffit panels. That's the two things that stick out. If you can post the SketchUp on one of the free hosting services, that would make it easier. - Stuart -

Stuart Thanks for the quick response. THREE LEAF WALL: I did not think this would constitute a three leaf wall. The outer wall belongs to the live room. The next wall is the wall to the control room. The false wall framing inside is just for the baffles that the speakers mount to. The bottom part of the wall is covered with fabric. Broadband absorption is located behind the fabric. I tried to build this similar to a studio on John Sayers Site. The framing is quite similar. If your thought is that the center piece between the baffles constitues a three leaf wall, then wouldn't the baffles them selves form a three leaf wall? Since most of the flush mount designs on this site seem to be constructed in this manner, I am not sure I understand where the problem lies, unless the proximity of the center board between the speakers to the front control room wall is the issue. It is approximately one foot away from the control room wall. Maybe I have missed something here. How would you suggest that center section be constructed? SPEAKERS OFF CENTER IN BAFFLE: As far as the speakers being in the center of the baffle. I was not aware they had to be exactly centered. My understanding was that the flush mount just allowed me to extend the baffle. The reason they are not in the center is because of the angles involved in getting the 60 degree triangle and maintaining the 38% mix position. I had to squeeze the speakers in a bit to maintain the required symetry. Do you have a link you can point me to details this requirement? I have looked high and low to find a build similar to this control room. The one below is as close as I can find. download/file.php?id=29412&mode=view ANGLE OF SPEAKER BAFFLES: Yes. Unfortunately I did not catch this until minutes after posting. I cannot believe I went this long and did not see reference to the maximum speaker angle. I don't know what to do here. Ten degrees would point the speakers over my head at the mix postion. How are folks accomplishing this type of control room approach? I went back to the design on John's site that is similar to this, and sure enough those speakers look to be only slightly angled. My speaker angles are about 26 degrees, and as you noticed are way out of wack according to "Best Practice" recommendations of this site. Do I have to abandon this whole "Speaker of the glass" design? Joe

xSpace wrote:

I'll see your 3 leaf and raise you a broken M/S/M!

Xspace Would you please elaborate? I have read John's site and a few books. I am definately no expert, but I am not sure what your specific concerns are. Maybe not seeing the ceiling construction is causing an issue. Would you please provide some more detail? I would be grateful. Thank you. Joe

I did not think this would constitute a three leaf wall. The outer wall belongs to the live room. The next wall is the wall to the control room. The false wall framing inside is just for the baffles that the speakers mount to.

Ahhhh! OK, that makes sense. from the model it looks like 3-leaf, but it's hard to figure out what is drywall, what is cloth, and what is baffle. I wish I could download your SketchUp to take a look in more detail, but if you say that it's just framing for the baffle, then it should be OK.

If your thought is that the center piece between the baffles constitues a three leaf wall, then wouldn't the baffles them selves form a three leaf wall?

The way I see it, the baffle doesn't count as a leaf really, since it is part of the speaker, acoustically speaking. The baffles (soffit front surface) is just an extension of the speaker baffle itself, and acts like an infinite baffle. But if you have something solid on the front wall between the speakers, then that isn't really part of the speaker, acoustically, as far as I can figure out, so I would think that it would be a third leaf. Remember, a leaf doesn't have to be sealed airtight in order to act like a leaf. It just has to be close to another leaf, with an air gap between. so if you have a solid panel there, then maybe you could consider changing that to cloth?

unless the proximity of the center board between the speakers to the front control room wall is the issue. It is approximately one foot away from the control room wall.

That would be my concern, yes. At one foot away it might not be an issue. depending on the mass/material/density, it also might not be an issue. But you should do the math to figure it out, or ask one of the experts what they think. I may be wrong (hopefully I am wrong on this!), but it might be a problem.

As far as the speakers being in the center of the baffle. I was not aware they had to be exactly centered. My understanding was that the flush mount just allowed me to extend the baffle.

Yeah, you really need to have as much surface around each side of the speaker as possible, or you won't really have an infinite baffle. I don't recall the figures right now, but I think the surface is supposed to be at least a quarter wavelength of the lowest frequency that the speaker can produce, with the speaker in the middle. So if your speaker goes down to 65 Hz, then the soffit should be 52 inches wide, or 26" on each side of the speaker. I think that's it, but I cant find my reference for it right now. Of course, you have to live with the space you have available, so if you can't make it that wide, then just get it as big as you can and understand that there will be some roll-off on the low end and maybe other consequences, but even so it still beats leaving the thing on a stand! --------- EDITED TO ADD: I have since learned that the speakers should NOT be in the middle of the soffits, but rather offset to one side or the other, in order to avoid creating peaks and nulls in the frequency response. It seems that a position about 2/5 of the width is good. They should also not be centered vertically, for the same reason. - Stuart - ----------

The reason they are not in the center is because of the angles involved in getting the 60 degree triangle and maintaining the 38% mix position.

Then I have some good news for you! 60° is not written in stone! If you have to angle the speakers tighter to make the geometry work out, then you can go up to as much as a 90° intersection angle, if you really need to! What you will be sacrificing is kind of "squashing" your sweet spot a bit, and your stereo image will be a bit wider than it should be, but that's a small price to pay in order to get the speakers positioned right and aimed right. It's a trade off that is well worthwhile. The 38% number is also not written in stone: It's just a starting point. In fact, most engineers end up sitting a little closer to the front wall than that, just becuase it sounds better there. In any event, the 38% point is the position of your EARS, and not the position of the intersection point! The speaker axes will intersect about 25cm BEHIND that point, since your head is round, not flat, and your ears stick out to the sides... Think about it, or draw a rough sketch on a piece of paper, and you'll see what I mean. The 38% point is at your ears, and the intersection of the speaker axes is quite a few inches behind your head, since the axes graze through your ears, not through the center of your head. And like I said, none of that is absolute. It is just ideal starting points. You can change it as needed, just recognizing that you might be sacrificing something in order to get something else.

Do you have a link you can point me to details this requirement?

I do somewhere, but can't find it right now! I asked the exact same question a couple of years back, and John replied with more or less what I said above. You might try searching the forum for it...

I don't know what to do here. Ten degrees would point the speakers over my head at the mix postion. How are folks accomplishing this type of control room approach? I went back to the design on John's site that is similar to this, and sure enough those speakers look to be only slightly angled. My speaker angles are about 26 degrees, and as you noticed are way out of wack according to "Best Practice" recommendations of this site. Do I have to abandon this whole "Speaker of the glass" design?

Well, Andre and I did a lot of research in this a while back (he did most of the research, I just read what he found), and we came to the conclusion that there are several different "maximum angle" recommendations, ranging from 7 degrees to 20 degrees. But NEVER beyond 20. There are multiple reasons for those different angles. The 20° limit is due to reflections and comb filtering coming off the desk, and the 7° limit is due the way the hum ear works to figure out directions and frequencies. The best recommendation seems to be the 10° limit, which comes from the EBU. If you go beyond 10°, you start messing with the way your ear perceives sound, and you also start getting comb filtering effects and other artifacts from reflections. So I really wouldn't go beyond 10° So, there might be a way you ca re-work the geometry to still get those windows in and still have no more than 10°. Perhaps you can fiddle things around to do that. But if not, then I'd chose acoustics over aesthetics any day, for a studio. If you can't get the speakers decently positioned, then you won't have a good studio, period. But if you can't see some places, that can be solved with video cameras and flat screens. Not so elegant, but it works. I'm not going to tell you what to do, but if that were my room and I couldn't make the geometry work without losing the windows, then I think I'd yell and scream a bit in frustration, bang my head on the wall, then bight the bullet and replace the windows with video links, in order to get my speakers in the best possible location. To my way of thinking, the entire room should be designed around the speakers, since the speakers are the whole point of having a studio! All the rest is just "fluff". The speakers are what matter most. That's what I'd do. But I'm hoping you can find a way to fiddle the geometry, since those windows do look cool! Here's a real curve ball for ya: Have you considered mounting the speakers IN the glass? I mean, using the glass itself as part of the infinite baffle? Glass should work well for that: it is very dense, smooth, flat.... Not sure how you'd do that in practice, but in theory it should work, I reckon... - Stuart -

Stuart Thank you for such a detailed response. I appreciate you taking the time to steer me in the right direction. Suddenly I don't feel so all alone in this venture. I have been thinking all day about your response to the speaker angle, and your statement about how important the speakers are in the control room. I agree. It doesn't make sense to put all of this time and money into the control room and sacrifice the main purpose. I was trying to avoid the video camera approach, but due to the speaker angle restriction of 10 degrees, I may have no other option. I am going to see if there is any other way to keep the visibility and the speakers. If not, I will try another approach and re-post. I appreciated your suggestion about using the speakers within the glass. Although, I had to laugh when I read that. It just might work, but I am so nervous about this whole project. I am the last guy that is ready to blaze a new trail. :lol: Thanks again for your guidance. I will see what I can come up with this week. Joe

Joe, In order to get the best performance out of a mass/spring/mass wall assembly the spring has to be fully enclosed to do it's job. That enclosure is provided by the >unbroken< wall partitions that actually create the air cavity that the spring will exist inside of. Your wall lines have breaks all over, therefor you will not have an effective high transmission loss wall assembly which is what you are wanting to do. Ideally you will re-draw your design to utilize the exterior of the basement to the best you can to maintain your mass/spring/mass. My hack paint re-touch only show the areas that I see that are in question. I have seen people draw and then build such things that have potentially a broken air cavity but could get away with this if the doors or what-have you remain closed during rehearsals or tracking, etc. It isn't ideal, but it works for them. But your walls are simply not sealed in so many areas as to make all the work and expense of little importance based on the potential of what you can actually gain with properly constructed wall lines and air tight wall assemblies.

Here's a real curve ball for ya: Have you considered mounting the speakers IN the glass? I mean, using the glass itself as part of the infinite baffle? Glass should work well for that: it is very dense, smooth, flat.... Not sure how you'd do that in practice, but in theory it should work, I reckon...

How interesting that you should mention that... Yesterday I was daydreaming about exactly that, and wondering if anyone had ever tried it. :) Essentially it's just making the 'infinite baffle' from glass, and allowing your window to extend behind the soffit. There must be practical limitations that make it unfeasible? Or perhaps it's just too unsightly. ;) (sorry I don't have anything meaningful to add Joe - but I admire and envy your sketchup skill!)

YES it has been done! Can't remember exactly, but wasn't it Wes who did that? http://www.weslachot.com/