Nashville Studio Build (need design help first!!!)

a time of celebration

haha... I understand this concept a little too well...always had to tell our drummer to get there at 7 if we wanted to see him by 9 at best! lol

Hey guys, hope everyone had a great 4th!! Or for those not in the states, a great random Wednesday lol...whichever way you may have celebrated. Anyways, I'd love to hear what you all think about the most recent design...I have been doing lots of research regarding other parts of my build, and I want to start running with some things but before I do I really wanted to get some constructive feedback. Some things I've been looking into... -I really want to shoot for an RFZ design in the control room so I've been looking into that and what it will take (got the Master Handbook of Acoustics in the mail a few days ago...whew what a read so far haha). However I can't find much regarding corner control room layouts and RFZ designs. I know it can be done since the principles are really the same... I just have learn how to apply it to my situation. Anybody got some links or good reads on this? -I also have been doing research on how I want to build my outer shell. I've come to the conclusion that something along the lines of "scissor" trusses would be ideal since it would allow me to get some extra height in the live room. I was hoping to meet with my builder today but it looks like he is busy until I get back from my trip to Lexington. My cousin's wedding is on Saturday and I'm the best man...should be a fun time 8) . Well that's it really...just wanted to give a quick update! Trevor

Alright, so I've been doing a ton of ray-tracing and it looks like it will be impossible to achieve a true RFZ given the small dimensions of the control room...the back two walls are too close to the mix position and there is no way to provide the necessary angles for deflection. The only answer it seems would be to pad that wall with a good amount of absorption in hopes that the reflections would at least be diminished in their overall dB level. However, there is no way to keep them from arriving within 20ms from the direct signal so it would not be a true RFZ (I hope I've got this concept right and didn't just sound like a fool :| ). I realize that shooting for 15ms and sometimes even 10ms is the best one can do but I really want to do this right since we are pretty much starting from scratch. Now for the more exciting part of the update... we've decided to talk to the builder about extending the concrete slab just a little further in a couple of directions (since we will already be tearing up concrete and pouring anyways)...I've attached a picture to demonstrate what we would be doing. The "unchanged concrete" is the part of the slab that is already level and well made; the "new concrete" is part of the slab that we were going to cut up and redo in order to square off the corners, tie it in better with the "unchanged concrete," and make it level; the "additional concrete" is the update I am speaking of here...it would allow for a few great enhancements to the studio: -more floor space in every room -larger air gaps in the walls between rooms for more isolation (using 2x6 studs as shown in the drawing with 24" oc) -a true RFZ design in the control room A couple things/questions to consider: -Given that the builder agrees this is possible (structurally speaking) we can add up to 4' of "additional concrete" before we'd be violating codes (the distance from the outer wall to the property line has to remain 5')...however I only went 3.5' because it keeps the live room 50% bigger than the control room (if I go 4', the live room is only 44% bigger)...Stuart I guess this is a question for you because I had read a post you made regarding this issue. You said something along the lines of, "the live room should be at least 50% larger than the control room otherwise the engineer would not be able to hear the reverb tails of the live room considering that the control room's reverb tails would 'mask' those of the live room"...this makes since to me however does this "volume/reverb" issue apply to the outer shell of the control room or the inner shell that is controlling the RFZ? I'm just trying to decide how much "additional concrete" would be necessary to create the most optimum dimensions for all the rooms... -Notice I've only drawn the inner shell of the control room on the right side...these angles provide a "reflection free zone" based on lots of trial and error with ray-tracing. However, I cannot draw the same angles on the left side because I have the sliding doors...this is where my question lies: is there any way I could keep the sliding glass doors and provide proper angles for an RFZ or is this one of those "compromises" where it's either sliding doors or RFZ? I realize one answer is changing the layout all together but I really like the flow that has been achieved with this one...and honestly I'm not too worried about sliding doors if I can have a great RFZ control room design. Sorry if I'm talking in circles... :horse: :) -What type of inner shell materials would provide reflections for a large enough range of frequencies? I've read many different opinions about RFZ and what range of frequencies need to be controlled...one opinion was that if you can achieve an RFZ down to 1k, then that would pretty much take care of any stereo imaging problems etc...what are your opinions on this issue? -Then depending on how low I would need to go ( :shot: ) (still talking about frequencies here lol) to achieve the best possible RFZ, would there be a limit regarding mass just because of a potential 3-leaf effect with the outer shell? I'm just a little confused on what materials would be used for this inner shell and how they would not create the dreadful 3-leaf effect :shock: ...also I'm assuming that whatever frequencies are allowed to pass through the mass, would then enter the cavity which could be designed to act as a trap (between the inner RFZ shell and inner drywall)?? am i crazy? :? -Oh... and I guess it goes without saying but we are sort of pushing the budget to the side for a while until we achieve exactly what we want out of the design...then we will scale down as need...but there's quite a bit of wiggle room in the budget if it means the difference between an average studio and a phenomenal studio. All in all we want the money to be well spent! Well I guess that's enough insanity for now...hope it was readable. And thank you in advance for any replies...I cannot express enough how much I appreciate the incredible services provided by this forum! Cheers Trevor

Also... the ray tracing is only a rough beginning of the potential RFZ... I realize there are several areas I have not adressed yet (not to mention the ceiling). I just wanted to get a better understanding of the materials and whatnot before I continued drawing like a madman... Thanks Trevor

Here is an example of the control room without the sliding doors... I was continuing my ray-tracing extravaganza and began to realize I have no idea how to tackle this in a way in which the reflections from the right speaker do not bounce back to the listening position off of the left walls (and vice-verse)...I got it to where the reflections from the right speaker off the right walls are good though! (that's not saying much I know...) So how do I go about designing such a wide space like this so that a true (or at least as good as possible) RFZ is achieved? Does anybody know of similar corner layouts that were able to achieve a good RFZ? I guess I might have to begin experimenting with monitor angles, placement, etc... A couple other things: -I've not been able to find specs that show the dispersion characteristics of my Event ASP8's...anyone know where to find such a thing? -Is there a way to design the soffits so that they can house larger monitors in the future but only my Event's for now? (I think I read where this has been done and also is recommended if an upgrade is foreseeable) Thanks guys Trevor

it looks like it will be impossible to achieve a true RFZ given the small dimensions of the control room...the back two walls are too close to the mix position and there is no way to provide the necessary angles for deflection.

To me, it looks like you have your mix position and intersect point too far back in the room. I think I would try to bring the mix position further forwards, and toe-in the speakers a bit more. That should help with your angles and times.

However, there is no way to keep them from arriving within 20ms from the direct signal so it would not be a true RFZ (I hope I've got this concept right and didn't just sound like a fool :| ). I realize that shooting for 15ms and sometimes even 10ms is the best one can do but I really want to do this right since we are pretty much starting from scratch.

What times are you seeing in your calculations? It's hard to get 20 ms unless you have a fairly large room. In other words, how long are your rays (from speaker to ear) for the earliest bounces off the rear wall? Also, it isn't just time; it is level as well. You need to get the level down by 20 dB. And getting both 20 ms and 20 db is really hard. 15/15 is easier, and probably do-able in your room. But looking at your ray-trace diagram, it seems that you are reflecting the rays at the front face of what I assume is a large superchunk on the side/rear wall: Why did you do that? Are you planning to wrap your bass traps with something reflective, like thin plastic, in order to keep highs in the room? Or is that a mistake?

You said something along the lines of, "the live room should be at least 50% larger than the control room otherwise the engineer would not be able to hear the reverb tails of the live room considering that the control room's reverb tails would 'mask' those of the live room"...this makes since to me however does this "volume/reverb" issue apply to the outer shell of the control room or the inner shell that is controlling the RFZ?

Pretty much everything is referenced to the inner-leaf surfaces: what you see when standing in the finished room, before any acoustic treatment is installed. And as with most "rules" in acoustics, then 50% figure is just a guideline: so don't go jump off a cliff if you can only get 40%, or whatever!! It is what it is. As long as there is a reasonable difference in size, you'll be fine.

However, I cannot draw the same angles on the left side because I have the sliding doors...this is where my question lies: is there any way I could keep the sliding glass doors and provide proper angles for an RFZ or is this one of those "compromises" where it's either sliding doors or RFZ?

I'm not sure I understand: the left and right side walls seem to be symmetrical to me. So what works for the right wall must also work for the left wall, regardless of whether we are talking about glass or drywall: there isn't much difference in reflectivity. Also, you might be taking your ray-tracing to unnecessarily high angles. It is mainly mids and highs that you should be concerned about, not lows. Lows are not directional, and act more like expanding hemispheres, while highs are very directional and act more like rays. Your speaker manual should show you what the dispersion angles are for each frequency band, so take a look at those polar patterns to see what type of angles you should be worried about. There is practically no high-frequency energy going out at angles of 60° or 70° off-axis: Most of it is going out in a cone within about 30° or so of the axis. So you might want to ray-trace out to, say 55°, just to be sure, but there's no need to go out to 80°, for example.

-What type of inner shell materials would provide reflections for a large enough range of frequencies? I've read many different opinions about RFZ and what range of frequencies need to be controlled...one opinion was that if you can achieve an RFZ down to 1k, then that would pretty much take care of any stereo imaging problems etc...what are your opinions on this issue?

1 kHz sounds about right, which is kind of what I was talking about above. You only need to worry about the top half of the spectrum (1k to 20k). The bottom half is not so important, and the lower you go, the less directional it is anyway. Your inner-leaf materials should not be frequency-based: the inner leaf is there for isolation, not treatment, so they should reflect all frequencies as well as possible. That's why you need heavy, massive, rigid materials, such as concrete, glass, drywall, brick, etc. Different parts of the spectrum are governed by different physical characteristics.

-Then depending on how low I would need to go (still talking about frequencies here lol) to achieve the best possible RFZ, would there be a limit regarding mass just because of a potential 3-leaf effect with the outer shell?

Not really: you seem to be confusing isolation and treatment. They are two different and opposite things. Isolation does one thing: it stops sound leaving the room. That's all it does. And obviously, if it is stopping sound form leaving the room, then it must be keeping the sound inside the room, where it bounces around all over the place, making the room sound bad. That's what treatment is for: to fix the problems created by the "bouncing around", which was in turn caused by the isolation. If you did not have any isolation at all, then you would also not need any treatment at all: Your studio would have to be in the middle of an empty field, with no walls or roof at all. With zero isolation, no sound ever comes back, so no treatment is needed. But since that is a bit impractical, you have to have a room around you, so that's where the problems start. Any type of room at all implies some amount of isolation, which in turn implies some level of "bouncing around", therefore needing some form of treatment. The better the isolation, the WORSE the room sounds, so more isolation is needed. So try to think of your build as being two entirely different things: Isolation to keep the sound in which makes your room sound bad, and treatment to make it sound good again.

I'm just a little confused on what materials would be used for this inner shell and how they would not create the dreadful 3-leaf effect :shock: ...

I don't think I understand: There should be only 2 leaves: the outer one (the building wall itself, probably) and the inner one, which is what gives the room its shape. If you stand inside the room after you finish building it, but before you put any treatment at all in it, then what you see around you is the inner leaf. Everything you add after that is treatment, and that will be mostly absorption, perhaps some diffusion, and perhaps some form of resonant device. So building your inner leaf should not ever create a three-leaf system, unless you built the outer leaf wrong, with two leaves. About the only except I can think of is a panel trap (membrane trap), which could theoretically create a 3-leaf system, but in that case it is only a small part of the total wall area that would be 3-leaf, and since that trap would most likely be tuned to a much higher frequency that the MSM resonance of the wall itself, it shouldn't be an issue.

also I'm assuming that whatever frequencies are allowed to pass through the mass, would then enter the cavity which could be designed to act as a trap (between the inner RFZ shell and inner drywall)?? am i crazy? :?

Now you are really confusing me! The only "cavity" is the one between the inner leaf and outer leaf! What cavity are you talking about? The "RFZ shell" is the inner-drywall! So how can there be an cavity between that drywall and itself, when it is the same thing? You lost me there... :?: :shock: :!:

-Oh... and I guess it goes without saying but we are sort of pushing the budget to the side for a while until we achieve exactly what we want out of the design...then we will scale down as need...but there's quite a bit of wiggle room in the budget if it means the difference between an average studio and a phenomenal studio. All in all we want the money to be well spent!

Ahhh! Yes, about budget. The correct way to estimate the budget for a studio build, is to come up with the largest possible amount of money that you could ever image spending on it, multiply that by a randomly chosen number between 2 and 10, add the cost of an outrageously expensive luxury car, then add a couple of zeros on the end... :) - Stuart -

Hey Stuart thanks for the detailed reply!!! Sorry I did not get back to you yesterday...I was not feeling well and couldn't keep food down all day...feeling a bit better this morning...not sure what got into my system :? Anyways...I think I should clear up what I was thinking I could do to achieve the desired RFZ...I had read in a few posts that the inner shell of the control room (the drywall) could be thought of as the "isolation" and then smaller partitions (walls made of thinner wood/mdf I guess? and then filled with insulation behind?) could be built within that inner shell (the drywall) which would control the angles of reflections for the mids/highs as well as act as bass traps...however based on what you are saying it looks like my line of thinking was completely wrong. :( The reason I thought that some people took this direction was that their rooms could not be built to accommodate the proper RFZ angles with the drywall (isolation wall) itself...therefore they talked about building "false walls" and "false ceilings"...however I must have confused what it was they were talking about. So are you saying that the reflections for the RFZ MUST be controlled by the drywall angles (or in other words, inherently WILL be controlled by the drywall)? And the only thing left beyond that is absorption, resonators, and possibly diffusion to treat the room? But there is no controlling reflections for RFZ beyond (within) the drywall? (I just thought there were different types of panels and whatnot that I could build within the drywall to help control reflections and complete the RFZ...at least in the few trouble spots that are created by my corner control room design...is this not accurate thinking?) I'm currently working on ray-tracing this room again...WITHOUT those inner "false walls" that I thought could control the angles for the RFZ... :oops: I will return with a new drawing giving times etc...I'm sorry about all the confusion I caused...things I read on here can sometimes be misleading for a newb like myself...anyways thanks again for the reply Stuart! I can't thank you enough. sincerely Trevor

and then smaller partitions (walls made of thinner wood/mdf I guess? and then filled with insulation behind?) could be built within that inner shell

Well, you certainly can add panels inside the room to move reflections to different locations. Once example of that is a hard-backed cloud. Another is a gobo. But putting insulation behind won't affect how well it reflects. And if it is over a sealed cavity, then you have created a panel trap, which will resonate and absorb energy at a certain frequency, or range of frequencies. So it will reflect mids/highs, resonate at its tuned frequency, and perhaps absorb some lows, depending on the design. If you really want to go that route then you could, but it is going to take a lot of calculation to figure out your resonance, reflection range, and absorption range, in addition to just figuring out your reflection angles. And what frequency would you tune it to? If your room is non-rectangular, then you cannot easily predict the modes of the room. So you'll have to wait until the room is entirely finished so you can measure the modal response, then build your tuned/reflective/absorptive panel traps. Another issue is the risk of creating a third leaf: Any time you place a large flat massive surface close to a 2-leaf wall, then you turn it into a 3-leaf wall, which can reduce isolation in the lower end. So you'd have to take that into account when you design your isolation system, to make sure that you have more mass on the middle leaf and a larger air gap, in order to compensate. So you could do that, with sealed tuned reflective absorptive panel traps, but it will be a lot of work to figure out all those things. Another option is to do what John does, using slot walls. They can be tuned to be broadband absorbers, while also being largely reflective and also somewhat diffusive.

therefore they talked about building "false walls" and "false ceilings"

Do you have any links to threads where people have done that successfully, where the face of the "false" wall is something substantial, such as drywall?

so are you saying that the reflections for the RFZ MUST be controlled by the drywall angles (or in other words, inherently WILL be controlled by the drywall)?

It's not that they "must" be controlled by the inner-leaf, but rather that this is usually the easiest way to do it. If you add a third leaf in front of that, either sealed or not sealed, then you have changed the room dimensions, modal behavior, and isolation, so you need to consider what effects you might be creating like that. For example, let's say you tune your panel trap to 1000 Hz. So now you have a surface that is reflective for most frequencies, except for 1000 Hz. So music reflecting from that surface will be deficient at 1000 Hz. You will have sucked out some energy from the music around that frequency, and the reflected sound will now be lacking that. Is that what you want? If the partition is thin, then it will also allow low frequencies through, which will then bounce off the "real" inner leaf behind, and come back out again at a different angle, and also delayed in time. So the low end will be smeared in time and space, and also reduced in level with respect to the rest of the spectrum. In other words, your music will have a notch cut out of it at 1 kHz, plus timing and phasing issues in the low end. That might not be what you want in a control room! :)

And the only thing left beyond that is absorption, resonators, and possibly diffusion to treat the room?

Those are three normal ways of treating a room, yes. There are some others, but not really applicable to home studios.

things I read on here can sometimes be misleading for a newb like myself.

And for the rest of us too! Acoustics is a little bit counter-intuitive in some aspects, and even simple things can turn out to be far more complex than you expected, once you get into it! :) So, to summarize: yes you could use panels to help create your RFZ, but you'd have to do so with care to avoid messing up other aspects of the room. In fact, an offshoot of RFZ called "CID" (for "controlled image design") does just that: it sets up many large, angled panels at various key points around the front of the room, to better direct reflections away from you. So it can be done, but it isn't as easy as a "standard" RFZ design. - Stuart -

Ahh that clarifies so much!! Thanks Stuart...let me do some homework and hopefully my next post will be something much more substantial. I'd like to avoid making an RFZ design any more difficult than it needs to be! I'm definitely not ready to attempt something that even a professional is hesitant towards... That being said...I guess my options now are to keep the room as is (or pretty much as is) and not go for a full-out RFZ (if I went that route, do you think this particular corner room could be made to sound good with proper treatment once it is built and the modal response is measured?)...or I could change the layout altogether so that I can achieve a more standard RFZ with proper drywall angles...I'm trying to decide how much I need to shoot for this whole RFZ thing...I've read so many testimonials where engineers love the results and say they can mix for longer periods of time without becoming fatigued by an overly "dead" room...I'd really like to achieve the more "natural" sounding control room that an RFZ can provide. Ahh decisions decisions... Cheers and thanks again! Trevor

Actually, the shape of a corner control room is inherently RFZ... :) RFZ is much more about the angles in the front half of the room, particularly the side walls, and pentagon shape fits that very well. Your issue isn't so much the angles at the front, as the absorption at the rear. The basic concept is that the front of the room sends first reflections around the engineer, towards the back of the room, where they can be absorbed, diffused, or re-directed in order to fit the "20/20" criteria(20ms & -20 dB), or the 15/15 criteria. So all that you really need to do is to ensure that the length of any first reflection path is at about 20 feet (or more) longer than the direct path from speaker to ear. In a normal rectangular room, if your ears are more than 10 feet from the rear wall then you already complied with that condition. In your room, I'm not sure what those distances are like, but it looks like you might be OK there. That's why I asked (a few posts back) what your path lengths and times were like. The second part of that "20/20" criteria, is the "-20dB" bit, which means that even when the reflections do eventually get back to you rears, they are 20 dB quieter than the direct sound. So you need thick absorption on the rear of the room in order to help accomplish that. Use something that has a coefficient of absorption greater than 0.9 for all of the frequencies you are interested in. Make that absorption thick, and space it away from the walls, and you increase effectiveness. If you room is big enough, then diffusers are another option, since they "scatter" the energy in both time and space. I'd be thinking along those lines. - Stuart -

A couple quick questions regarding my next design... I was reading a post that "knightfly" made on this thread about air gaps in iso walls...

The more space you can leave between the outer and inner mass leaf, the better your iso, especially in the bass region - 8" is good, 12" is about the max before it doesn't help much. Generally, use as much space as you can up to 12", and fill with insulation.

My design currently shows a 15" air gap between the double drywall of the inner walls (room to room)...is this wasting space considering knightfly's post? Should I bring this back down to 12"? One other question...I'm trying to figure out how much space I need behind/around the monitors in the soffits (so between the back/sides of the monitors and the drywall isolation wall)...from what I can tell in all my research it seems like the more space the better since it allows for extra insulation etc. and therefore more mass. I'm trying to balance this out while also pulling the listening position closer to the front of the room...I'm tempted to go with something like a 70º or 75º intersect point so that I can keep the glass width that I have, pull the mix position forward, and keep enough space behind/around the monitors in the soffit (it also helps eliminate one of the shorter first reflection points)...does this sound reasonable? Is there a standard for space behind/around the monitors in a soffit design? Also, Stuart I've done some quick calculations after pulling the mix position forward (almost 2') and it looks like with the shortest first reflection path I have a 17ms time delay between the initial signal reaching the ears and the first reflection reaching the ears. That may be the most I can get out of this room but I figure that's pretty good! BTW I added an extra 6" to the bottom and side of the control room since I had the space to spare in accordance with the 5' to property line code...the extra half a foot helped get that 17ms. I'll post a more detailed analysis and drawing soon... Thanks! Trevor

My design currently shows a 15" air gap between the double drywall of the inner walls (room to room)...is this wasting space considering knightfly's post? Should I bring this back down to 12"?

Yeah, 15" is overkill, assuming that you have plenty of mass on each leaf. The relationship is not linear: isolation drops off very fast for gaps smaller than about 4", increases well up to about 8", less so up to about 10", and even less after about 12": the curve gets flatter and flatter. So you could probably bring that down to 12", or maybe even 10", depending on how much isolation you need, and what frequency you need it at.

One other question...I'm trying to figure out how much space I need behind/around the monitors in the soffits (so between the back/sides of the monitors and the drywall isolation wall)...from what I can tell in all my research it seems like the more space the better since it allows for extra insulation etc. and therefore more mass.

More space is useful, but it isn't lie or death. The insulation inside the soffit cavity is just there to provide some damping, not really for isolation, and the mass isn't too important: You can use that cavity as your "insulation dump", for all the offcuts of insulation from the rest of the build, as well as anything else similar: dirty laundry, old blankets, or whatever else! :) So you don't absolutely need a lot of space in there. What matters with the soffit is mostly the size, mass, and rigidity of the baffle itself (front panel of the soffit, the one with the hole in the middle that the speaker pokes through). That's the critical factor.

... does this sound reasonable?

That would probably be fine.

and it looks like with the shortest first reflection path I have a 17ms time delay between the initial signal reaching the ears and the first reflection reaching the ears.

:thu: Sounds good to me!

I added an extra 6" to the bottom and side of the control room since I had the space to spare in accordance with the 5' to property line code

talk to your neighbor, and see if you can move the property line another couple of feet!!! :shock: :!: That would give you the extra 3 ms.... :) (Just kidding! 17 ms is fine.)

the extra half a foot helped get that 17ms.

Great! So now you just have to figure enough absorption/diffusion to bring the level down 20 dB, and you'll be home free! This is starting to sound really good (no pun intended!). - Stuart -

That clears up a lot!! Good to know it's starting to "sound" good lol.. Thanks Stuart! So here is my new attempt for the layout...guess I'm calling this one 11.1 :roll: :) List of adaptations (and a few..ok a LOT of questions): -I reduced the air gap between the inner walls from 15" to 12" (this gave me an extra 3" at the top of the control room so I pushed out the right wall another 3" to compensate for symmetry...this also increased the time for the first reflection to 17.45ms woohoo :yahoo: haha) -The line of sight between the control room and live room is now slightly more "on-axis" with the top left corner of the live room. This was another positive result of reducing the air gap. It pulled the glass over and up to the right a bit. Can't complain about that. -I added a sliding door between the control room and iso booth. -I also added a 6º angle to the sliding doors/walls. For some reason this looks very awkward to me and I can't figure out what I may have done wrong. I know 6º is not much (is it even enough?), but with those 2x6 studs it appears to be very steep. Is it possible to angle the glass without angling the walls? I'm losing a decent bit of space in the booth by splaying the walls like that. :( -I went with a 76º intersection point at the mix position (38º speaker angles just seemed more realistic than 37.5º). -The front of the baffles turned out to be 4' 5 1/8" wide. I just extended them all the way to the drywall around where the glass framing would start...is that ok? Glenn's drawing (as well as my past few drawings) showed some kind of extension between the soffits in front of the glass...is it critical to join the two baffles (L and R) across the top and bottom of the glass like that? -There is about 5' 6" between the front wall and the listening position (given the intersection point is 18" behind the engineer's head, per Glenn's advice)...does this seem about right or do I need more space there? I do plan on buying a console/desk somewhere down the road... -I read that the monitors should be positioned at a point that is 2/5's the size of the baffle width (rather than centered in the baffle)...is this referring to where the center of the monitor should be, or the side of the monitor? Wasn't really sure what to do there... -After ray tracing out to 55º on both sides of the left monitor, the only path that is a first-reflection "problem" is the one that basically hits straight off the right wall and reflects back to the right ear. This is the path that I calculated having a distance of 25' 11 3/16" from which I subtracted the direct path from speaker to ear which was 6' 3 7/16" which gave me a difference of 19' 7 3/4". I turned that into decimal form (19.64583333') and divided it by the speed of sound (1126ft/sec) which gave me .017447 seconds. I multiplied that by 1000 to get the milliseconds and as I already stated earlier that turned out to be 17.447ms. :ahh: Whew that was a lot of numbers...anybody out there wanna check my math?? :D (granted this is dependent upon whether that little circle is accurate to the size of a human skull...of which I did not measure) -Does it matter that one of the 55º rays from the left speaker bounces off of the right baffle before heading towards the right wall (and obviously vice-a-verse)? -Ok I think this is my last question for now. Do you think the door going into the control room has enough space on the right side for proper/substantial framing? Stuart I know you recommended against the superdoor but I want to keep my options open. I will be getting into more of the detailed budget pretty soon and if a superdoor ends up being cheaper than double doors, I might go that route. I just want to make sure I'm allowing for this possibility if it were to be a money saver. I've provided an image of the section I'm referring to. And finally...I'm sorry for such a long post! I just had a lot of things I wanted to cover. And again thank you thank you thank you for everyone's help...I would definitely be ramming my head against walls by now if it weren't for you guys. And Stuart... you tha man!!! Cheers Trevor

Hey Stuart I think this might answer one of my questions from above...

Also, it's a myth that you must splay the glass for acoustic reasons: there are no acoustic reasons why you would want to splay your windows.

I saw where you said this to one of the members on the forum (shayneallen) who is also building a studio here in Nashville... Anyways does that "myth" then also apply to sliding doors? Could I keep them parallel so that I wouldn't unnecessarily waste space (in the booth) that could be used for bass traps, resonators, etc? Thanks as always Trevor

Anyways does that "myth" then also apply to sliding doors?

Yup!

Could I keep them parallel so that I wouldn't unnecessarily waste space (in the booth) that could be used for bass traps, resonators, etc?

Yup! (Who said that I can't give short, concise answers? :) ) - Stuart -

Haha thanks Stuart!! I'll re-post my drawing with the parallel walls... But before I do...did you see any other "red flags" in layout 11.1 (as far as the floorplan is concerned)? I realize that some of the stuff in the control room can be tweaked for awhile without affecting the outer shell (monitor angles etc). I'm just wanting to finalize the floor plan so my builder and I can start working toward the goal of designing the outer shell...I just want to make sure I have it perfect before any major plans are drawn up/concrete is poured etc. I'm going to start researching HVAC systems in more detail to figure out how we could go about it with this type of floorplan... Let me know what you think! Cheers Trevor

I found the post from John that I mentioned yesterday: viewtopic.php?f=1&t=14215&p=99679&hilit=necessary+to+angle+sliding+glass+doors#p99679

"...it's not necessary to angle sliding glass doors. I used to think it was but I don't angle them now."

So there's your permission slip to not angle that bit! :)

But before I do...did you see any other "red flags" in layout 11.1 (as far as the floorplan is concerned)?

Yeah, it's terrible! Red flags all over! Do it again! :shock: :!: :!: Naah, just kidding: it looks pretty good. Time to flesh it out in 3D, I'd say, and start figuring basic treatment.

I just want to make sure I have it perfect before any major plans are drawn up/concrete is poured etc.

Regarding concrete pouring: have you considered embedding your electrical and signal cable conduits in the concrete? Makes it a hell of a lot easier to cable things up afterwards... Cheap and easy to do now, hard and expensive to do later... Just a thought... - Stuart -

Great to know I've got John's approval! (BTW I think your link is broken) In regards to running cables in the concrete...I had thought about this awhile ago but since we aren't pouring all new concrete I figured we wouldn't be able to (refer to the concrete diagram on page four). For reference though, I've drawn dotted lines to represent where the new concrete will be in relation to the floorplan (as seen below in layout 11.2). Everything to the right and below the two dotted lines will be new concrete but the upper left segment is already fixed. Can I just run my cables through the studs/air gap around the walls to the positions I want the wall plates in each room? Here is the layout with some modifications: -Changed it back to the parallel sliding doors...it makes the booth so much nicer! -I mirrored/reversed the way the door opens out from the bathroom...it seemed more logical/better to enter on the side opposite the front door. That's about it really...the only thing I am really contemplating now in regards to the layout is the angle on the front of the booth...it's currently a 14º angle upward from the corner of the control room. I think it's pretty much the best compromise in terms of sight lines and space. Seem okay? Onward! Trevor

After talking to my Dad earlier, he made me realize it would probably be worthwhile to go ahead and incorporate conduits in the new concrete to the live room, booth, and maybe even the bathroom (this was my idea in case I ever wanted to throw a panel in there down the road for an extra "semi" iso booth). We wouldn't be able to put them in the most ideal positions in the live room...but at least there would be some type of channel to send a line through after the build is finished if we ever needed to. We would still have to run a couple snakes through the wall cavities to reach spots in the live room that I consider more "ideal". Does this sound like a good idea? It's more of a precautionary, might-as-well-do-it-while-you-can sort of thing... Anyways, thanks for pointing that out Stuart...let me know what you think about it and I'll draw up a conduit/cable routing diagram to see what would work best. Trevor

(BTW I think your link is broken)

Damn! Don't know how I managed to do that. But I fixed it now. Thanks!

Can I just run my cables through the studs/air gap around the walls to the positions I want the wall plates in each room?

You can, yes, but if you have the opportunity to put some of them in the slab, it makes it easier. However, you should only have ONE penetration into each room, and distribute from that point to all the plugs, boxes, lights, switches, etc. It's not a good idea to have multiple penetrations, as each one is a potential breech of your isolation. That's why we normally recommend using all surface-mount ducts and boxes inside each room. Minimize penetrations as much as possible.

-Changed it back to the parallel sliding doors...it makes the booth so much nicer!

Yup! You could do some angled slot walls in there, better acoustics.

it's currently a 14º angle upward from the corner of the control room. I think it's pretty much the best compromise in terms of sight lines and space. Seem okay?

Looks good to me. Seems like you have pretty decent sight lines in all directions. - Stuart -

Hey Stuart...for some reason I'm not quite sure what you mean by this...

That's why we normally recommend using all surface-mount ducts and boxes inside each room.

Thanks for the quick reply though. This week I am going to meet with my builder to show him the final floorplan. We should be able to get a better idea of how the outer shell will be built at which point I can proceed with working on the HVAC design, electrical, etc. I do have a couple quick questions for you whenever you get the chance... -I began working on the 3D model but since I have not shopped around for doors and whatnot, I feel like I'm wasting my time by drawing in "temporary" details. Wouldn't it make more sense to go ahead and shop around so I can determine exactly what I will be installing before I get into the messy details of SU? (It seems like the superdoor at the entrance and the beefed up bathroom door might be cheaper just to build ourselves...but not the sliding doors or double doors into the CR) -In a "room within room" structure such as what I am preparing to build, where is the most typical path for HVAC ducts? In between the framing of the outer roof and inner ceiling? Or perhaps in the space created by the trusses on the outer roof? I am going to continue my research in this area, but I just wanted to make sure that I was on track...at least a little bit. Thanks! Trevor

What I meant by that was that the normal way of installing switches, outlets and lights, in normal houses, offices etc. (not studios) is to cut a rectangular hole in the drywall for each one, poke an electrical box through the hole, connect up the cables, then attach a switch plate, outlet plate or light fitting plate, as needed. But with a studio you cannot do that: each such hole would drastically degrade your isolation: You CANNOT make holes in your drywall anywhere. So your only option is to use surface-mount boxes that go on top of the drywall, sticking out from the surface and NOT going through it. So there is no penetration of the drywall. Of course, this means that the entire box is visible, so you need to use boxes that are specifically designed for surface mounting. It also means that the wiring between boxes also cannot penetrate the wall, and must be done on the surface of the wall, where it will also be visible. So once again, you use structured surface-mount ducts for your wiring, that attach to the wall surface. It can look quite attractive if done correctly. There are several manufacturers who make this kind of surface-mount electrical hardware: I have used both Legrand and Kalop, but there are others. I'm not sure what you can get in your area, but look around and I'm sure you'll find something suitable. If you are doing inside-out walls then this is not so much of a problem as for "normal" walls, but even with inside-out it makes things easier and neater to use a structured system and proper surface-mount hardware. You can still cut all those huge holes in your wall if you want, and do things the conventional way, but then you have to take great care to seal around the back of each box with putty pads, using enough to replace the mass and seal that you lost with the hole, and creating many more headaches for yourself than you need! :) On the 3D model: Doors come in several standard sizes, so it's an easy thing to just create the rough openings in your framing to be the correct size for the nearest standard door, even if you don't put in the detailed door yet. So for example, if you had sketched in a door that was 31-1/8" wide, then change that into a standard 32" door, and do the framing accordingly for the rough opening for a normal 32" door. Don't forget that the doors will be VERY heavy by the time you have modified them correctly, so normal practice is to have three studs on each side of the rough opening. The best place for HVAC ducts is wherever they will fit! :) You'll need silencers each time they pass through a leaf, and the silencers also take up a lot of room, so take that into account. - Stuart -

Ahh that makes much more sense now!! I had planned on just cutting holes in the drywall and using putty pads to seal, but now I realize I've seen exactly what you are describing in many of the construction threads...just now putting two and two together :idea:. Definitely seems like a much safer route, isolation wise. One question on this though...from what I've seen of surface mounted mic panels, there is one small hole in the drywall that allows the snake through...but from what I can tell by your post, there should be NO holes at all...I guess I'm confused as to how there can be absolutely no holes in the drywall and still allow for the cables to run into each room...does the penetration happen through the floor where the conduits in the concrete empty out? And then the snake is run around the room via a wall surface mount if other panels are required in the same room? Am I thinking about this correctly? That's also good to know about the doors! I figured that was the case...but since I'm no home builder (or anything close to it), I had no idea what those standard sizes were. And yes I will definitely account for the weight of the doors! Since I'm using 2x6 studs, is it still necessary for three on each side of the framing? In regards to the HVAC, I have been getting into more detailed research... wow I must say it is pretty overwhelming! I have so many calculations ahead of me! :shock: But after the meeting with my builder today he told me that if I figure out the specs for what I need (BTU output, fresh air needs, conditioning, volume/velocity of circulation, etc) then he can let his HVAC guy direct me towards the best type of unit that will accomplish my needs. Basically it will save money if I do all of that work myself. These calculations will also allow me to figure out how big the ducts need to be in order to achieve the proper velocity coming out of the vents (I read that should be 100-300fpm maximum in Rod's book). Knowing the size will then allow me to properly design the trusses to accommodate both the silencer boxes and ducts within the roof/ceiling structure. One question on this...I read somewhere that the silencer boxes need to be accessible even after the build is complete...does this mean I have to make soffits so that each silencer box actually resides within the inner leaf (double drywall)? Or can there be some kind of access door to the attic space (which poses another potential isolation breech)? One other update...in our meeting today my builder, Joseph, expressed further concern about the large tree by the foundation. The two major problems are potential root damage to the concrete (over time), as well as the possibility of a bad storm causing the tree to fall either by lightning or wind (that would be a lot to risk for such an expensive structure!). So, I decided to call a tree specialist who is going to meet with me ASAP to assess the situation. We will then come to a decision about whether to cut it down or not... :cry: Honestly, I'm not looking forward to seeing this thing go...I'm still hoping for the best but it's not looking good. Anyways, thanks Stuart for yet another great reply!! I've got plenty to keep me busy in the meantime... Cheers Trevor

A couple more updates... 1.) I met with a tree specialist a couple of days ago and he basically informed me that the wisest plan of action would be to take the tree down during the demolition phase of the existing structure (so before we dig and pour the additional concrete). He said if I were to keep the tree, there is a high probability that it would die sometime in the next 5 years due to the soil becoming compacted during construction. This cuts off proper oxygen supply to the roots which leads to all kinds of problems for the tree :( . This is not to mention the obvious danger of a bad lightning and/or wind storm causing the bone-wrenching reality of walking out to a studio with a caved in roof :shock: . So anyways...the beautiful Silver Maple has to come down... :cry: (moment of silence) 2.) Now that the tree is no longer an obstacle, I have drawn up two more layouts. The first one (Layout 11.3) is just like 11.2 but has concrete in the upper right corner to square off that notch where the tree would have been. I was able to incorporate a small storage room alongside the bathroom...no angled walls here as I tried to keep it as simple as possible. The second layout, which I'm going ahead and calling Layout 12, is a whole other beast in and of itself. This one has additional concrete extended 2' 9.5" on the entire right side of the structure. This squares off the outer shell (34'2" x 34'2") which accomplishes several things: - The line of sight between the control room and live room is at the absolute optimum due to being completely on axis from corner to corner. - Both the booth and live room are a little bit larger (not to mention the shape of the live room feels better all around). - There is room for a decent size storage/mechanical room between the CR and LR. This would be a huge step up from previous designs but obviously will have a price tag too. - The bathroom is also a bit larger. Anyways, let me know what you think of these layouts. I know this just keeps growing bit by bit...however our reasoning behind this is to go ahead aim for the most ideal design, get a quote, and scale back from there if we have to. Our builder wants to help us do this as cheap as possible and isn't looking to make the kind of money he makes on normal home construction. His team will be in the neighborhood for awhile because they keep buying new properties to build on and/or renovate considering it's the perfect "up-and-coming" neighborhood for a good profit margin. So he will not have to make special trips with equipment to get the job done. Fortunately, there's this convenience factor that he is taking into account. In the meantime I have been reading a lot in the construction threads as I need to learn as much as I can there...ceilings are my new priority as I am probably the most clueless in that area of the build. Thanks in advance for any input!! Trevor

So I'm pretty sure I might be nearing the record for "most proposed designs" for a single studio on the forum...that being said, I've got one more for ya!! :horse: :shock: :D Anyways, after increasing the potential size of the foundation to a perfect square (34'2" x 34'2") I realized I needed to rethink other possible layouts, just in case I came across something better than the corner style control room. And by "better" I mean something more suited to my needs, as listed earlier in the thread (large live room, small but workable control room with a RFZ being the priority, etc). I think I may have found just that...and I'm calling it "Layout 13" **insert dramatic music** 8) Alright alright so here are the specs and reasons for why this might be a better direction to go in: -HUGE live room (473sq ft)...a solid 47sq ft increase from the largest corner CR layout (layout 12). -Complete RFZ in CR with first reflections coming in at 20ms after the direct signal reaching the ears...wooo!!! -Less square footage in CR (57 sq ft less) which allows for extra space in LR and storage room. -CR now has a back wall...perfect for hangers/absorption and whatnot (and not just a corner trap). -One less door is used in this layout as well as less glass at the front of the CR (money saver). -Drum booth square footage remained the same. Let me know what you guys think...I personally feel like the benefits of this design far out weigh the negatives. However, I need input to help me either confirm that or set me straight! :lol: Thanks in advance!! Trevor