Ready to start construction. Any last minute advise?

Hey Steve, At first I won't be doing any 5.1 mixing. I'm just preparing the room for it. I intend on starting off w/ just 2 mix stuff, and as budget allows, I'll start purchasing the necessary equipment for 5.1. These walls on the diagrams are more or less the detailed drawings. The thickness is that of the framing (4" actually). With the exception of the outside foundation (block). In other words, where you see green on the drawing, that will be the new walls. Are there any area's of concern on this drawing? Thanks, Aaron

Only areas I see would depend on your definition of a "wall" - where there is only one wall shown between separate areas, I'm going to assume that there's paneling on BOTH sides of that frame - wherever you show double walls, there should be paneling ONLY on ONE side of EACH frame. The key here is 2 mass, one space. Imagine yourself as being a "sound" - anywhere you look on your drawing, if you wanted to get from one area to another, you should have to get thru a MASS, then an AIR space (insulation counts as air space), then ANOTHER mass, then you should BE in the second area. Your drawing is NOT a detail drawing, BTW - a full detail of a wall would show exactly what is connected to what, including framing members, which part goes on top of which, what layers of paneling are made up of and what order they go in, etc - these are the details that determine whether your studio LOOKS cool, or actually WORKS - there are SOME details that, if overlooked, will negate all you've done. There are others that won't, but to keep from making an expensive and disappointing mistake you need to analyze EVERYTHING you plan to do from the perspective of a little "sound termite" trying to get through - or, in the case of treatments, where will that little "termite" bounce to, and how much energy will he have left when he gets there? I have another wall detail almost ready to go, but am out of "attachment space" - Emailed Peter and hopefully that will get fixed soon. Meantime, re-examine your drawing from the "termite" viewpoint, and see if you have any paths with either too many or too few "leaves"... Steve

It may be awhile before I get that kind of detail. At the moment I can't splurge the $200 on purchasing the Smartdraw program (gotta get tires for the vehicle, and going to Chicago for Thanksgiving), and my trial copy is expired. I would use autocad (which I have), but don't know how to use it. For that much detail, I'd might as well go drop a few grand with a designer. But, since this is the real world, and small budget, I'll have to come up w/ another plan. I guess I'll scrub the drive and reload it all. I need to also do a drawing of just the control room alone w/ details. I've got the ideas in my head, just a matter of trying to draw them out is another challenge. I'm going to have questions on the soffits, etc before too long. I'll read through the other threads to try and figure some of that out, and post questions as needed. Thanks again, Aaron

Here's a wall/ceiling detail, showing two mass/one air space between any two areas, with some other info-

Aaron - I'd rethink your raer section - A vocal booth behind you with no vision is a bit useless IMO - you can have a booth to the right of the console where visial communication is excellent. Maybe do something like this. cheers john

Hey John, Actually there is a window in the drawing I posted. Granted I would have to turn around to see them, but for the space, I can live with that. Besides, I'd like to have a little sun light come through once in awhile. Otherwise I would have made a decision to block up the window and relocate the hvac unit and would have had lots more space for the control room. I like the idea though, but I can use that room for other isolation besides vocals. I intend to install another sheet of glass for the window to give a little better isolation from outside. Thanks.

Plus with John's Modification you get additional bass trapping. remember you can almost never have enough. Bryan Giles

Not to mention, I've already constructed the framing for the floating floor for that section,

Steve, Did you ever get a chance to draw up the DIY sway bracket?

Near the top of this page - I replaced the original dwg with a newer one. http://www.johnlsayers.com/phpBB2/viewt ... 8&start=45 Is that clear, or did you need more detail on the first of the two drawings where the wood stud wall meets the ceiling joists? Steve

I think most of that is clear. I'm going to post a question in my other topic under the construction thread to try and keep most of it on there...

Boy am I excited to see this site back up. I've been busy working on plans in autocad (and what a pain to use), and it's coming together well. Most of it is drawn up, but I've still got the fine details to fill in. Here's where I'm at with it today. It's not complete, but coming along. Some measurements are off by a 1/4" or 1/8" here and there, but the general ideas are here. I'll have to attach a pdf file since I don't have another way to paste from autocad...

here it is cheers john

Aaron, first keep in mind that I'm speaking from 100% theory here (sorry the chicken wire didn't work, BTW - I wonder if the tension was its downfall) Anyway, unless you are planning on doing a LOT of surround work and LITTLE stereo, I would consider forgetting the soffits for the surrounds, and just putting heavy absorption in those corners where the surrounds would be. My reasoning can be explained by a test you can do in Autocad - draw a line from the center of either(both, actually, but one at a time) to the forward edge of one of your surround baffle extension walls (soffits, if you will, or flush mount, same thing) now, however Autocad lets you do this, measure the included angle between the baffle extension forward of your new line, and the line itself - duplicate this angle toward the rear (in otherwords, "ray trace" your line from the speaker to the baffle of the surround, then to its next destination - there are several points where that ray will intersect your head. This means early reflections. So, unless you plan to do your baffle extensions as absorbed panels, you will get serious early reflections from the baffle extensions around your surround speakers with those angles. I don't know of any decent way to avoid that - it's just the geometry of it all. If you shorten up the baffles between the surround speaker and the front of the room, you end up with a "dogleg" - Either that, or you could leave your main side wall angles as they are and bring the entire wall in by about a foot - the upside of that would be a longer "RFZ" angled section on each side, so less early reflections reaching the mix position. The downside of that would be an even smaller volume in your CR. I'm not even sure what effect you would see by putting 2" 703 up around your surround speaker baffles in such a way that the front edge of the 703 was flush with the front edge of the speaker baffle - I don't think it would hurt much, since the shallower the angle of incidence the less absorption takes place, so it seems like the speaker wouldn't suffer from using a 703 surround, as long as it was still flush. As I pointed out earlier, this is all theory at the moment - surround is still so new that there's not anywhere the quantity of info available as there is for Stereo. I have a few books by some of the "gods", including TH himself, but haven't had time to get very far through them. So far, my assumptions have been much closer to accepted wisdom than I could have said 20 years ago, so I guess that's a good sign. Confused enough yet? I know I am... Steve

:? That just made my head spin a few times... (As far as the chicken wire, I tried different tensions. It was like a bad spring reverb or something.) I initially plan to be doing only 2 mix until budget will allow. The way things are going, 5.1 mixes will become more standard. I also have contacts w/ people that do DVD work as well, so this will be benificial down the road. I will design and make panels that I can hang on the walls in area's that need it when I do mix 5.1, down the road. For 2 mix applications, I will have hard surfaces on the front wall, and hang absorptive panels when mixing 5.1. I'm assuming this shouldn't be any problem. As far as the rest of the room, I have yet to figure out all the details on absorption, diffusion, etc. Any ideas would be great. I was planning on using the area on the other side of the front left speaker to use as bass trapping. That's about the only spot in the room I have for doing so, the way it's layed out. I was also planning to build/install a broadband diffuser on the back wall. Over the weekend, I've begun the construction of the control room floor. The left side as well as the conduit runs are already in place (about 2/3rds of the conduit anyway). The rest will probably be done by the end of this next weekend. The floating floor in the vocal/iso room next to where the bay window is, has been completed, w/ one wall framed up so far. Since I don't have a digital camera, I'm near the end of this disposable, so I'll post pix when I get them developed. There are a couple other things I'm trying to figure out. The inside wall on the left side of the control room. (where the bass trap will be). How should I construct this wall for materials, and best use of bass trapping? Thanks again, Aaron

Well, I've broke down and decided to purchase a book. I was looking over some of the threads and decided to order the "Master Handbook of Acoustics". Perhaps this will shed some light on some acoustical questions... BTW Steve, What did you mean by... [quote]My reasoning can be explained by a test you can do in Autocad - draw a line from the center of either(both, actually, but one at a time) to the forward edge of one of your surround baffle extension walls (soffits, if you will, or flush mount, same thing) now, however Autocad lets you do this, measure the included angle between the baffle extension forward of your new line, and the line itself - duplicate this angle toward the rear (in otherwords, "ray trace" your line from the speaker to the baffle of the surround, then to its next destination - there are several points where that ray will intersect your head. This means early reflections. Mostly the explanation of "baffle extention"??????? The whole paragraph baffled me... Thanks, Aaron

Ok, Here's some of the latest pix...

Some more...

Aaron, hopefully this will help explain my "baffling" comments - Steve

What, no comments or questions? I thought surely somebody would jump on this by now... :=)

Hey Steve, Still trying to figure it out. don't know how to use the Ortho feature. I can't set the settings on it (grayed out). So I was playing w/ the Polar command. It kinda sorta worked, but this program is quite overwhelming on trying to figure out. I was playing w/ some 3D stuff yesterday. Interesting. So in other words, the instructions and program are a little over my knowledge. Put me in a control room to wire up, and I can wire the whole thing without a glitch, but put me at the helm of this autocad, and whew!!... Aaron

Maybe Fitz can help with the Autocad ortho modes - I use a "wannabe" DOS cad proggie that scared Autodesk enough they BOUGHT the company and eventually phased it out (no Windows version, but runs fine as a DOS app) It will be very valuable to you to learn what you can about your own ortho modes - my drawing speed at least DOUBLED when I discovered that feature. Meantime, if your geometry skills are still good you can use basic compass/protractor methods and get there using my drawing and part of the instructions. You're just duplicating the incident angle for the reflective angle, so the method is the same... Steve

Bump

John, or anyone, What should I use to construct the interior walls of the control room? I am attaching a drawing of the control room. Not really sure if the walls should be solid, or if they should be designed differently for the bass traps? Or should I ask this question under the construction forum? Thanks, Aaron

Not sure if John has access whilst in Sydney or not, but I'll give it a shot (John, if I blow it I know you'll yell - I'll try to stick to what I know for sure though...) OK, here goes - Left, center and right front walls - massive. 6" concrete is good... :? Seriously, the stiffer the better. You'll be mounting your mains behind the walls, presumably on something like Barefoot's isolated speaker mounts (speaker forum) and the stiffer your "baffle extensions", or walls, the less they will flex so the less they will add their own character to the sound. Same with front center, by association and juxtaposition - plus, if you soffit a center channel speaker there... This does NOT mean you can't put a trap in those sections, just keep any (absorbed) openings at least 4-5 woofer diameters away from the speakers, in order to maintain a long enough path around the baffle extension so as NOT to cancel the "half-space" effect that is the main reason for the flush mounts in the first place. If you're not into pouring concrete walls on your floated floor, the next best thing would be something like 1-1/8" flooring plywood framed with 2x6 wood, faced with 3/4 MDF, faced with whatever wood or wall board you want, and in this case I'd make an exception and fully laminate all materials together to get the lowest resonance. Ideally, this speaker wall should be founded on bedrock and isolated from all other structure. Realistically, it should be at least isolated physically from your floated floor but I've not actually built this type construction before, so I'm almost completely talking out my ass here. I would look for some type of elastomeric isolator and "super glue", but a word of caution - when using isolators, you need either dumb luck or science. The science in this case is yet to become part of my vocabulary in any depth, as I said. All I know is that choosing the WRONG material/elasticity/thickness, etc, can be WORSE than not isolating at all. If you happen to hit the resonant frequency of the combined mass of your soffit wall and speaker and room combo, then you'll end up with a HUGE resonant spike in response and may have to start again from scratch. The least you would need to do to fix such a problem would be to add yet another layer to the wall to CHANGE its resonance relative to the suspension material, and you might need to reduce the thickness (or increase it) to solve the problem. The good news is, this isn't likely to be a problem if you use Barefoot's isolated mounts - big studios get away from it entirely by literally pouring concrete pedestals for speakers that are on large deep concrete footings - then the walls are built around (but NOT touching) the speakers. The walls into which surrounds will be flush mounted should be treated the same way, other than their surfaces should be absorbed whether or not you're mixing surround. This isn't as critical as the fronts, unless you plan on using MASSIVE mains and identical surrounds instead of a subwoofer(s). If you're NOT flush mounting surrounds and you DON'T need those rear side walls as part of the sound isolation, you could conceivably use those walls for bass trapping - Even just using 1/2" wallboard single layer would create a panel trap effect, but you'd probably get better performance making those into deep traps with absorbent between studs, hangers inside, and cloth over. Same with the rear center. Without taking the average height, width, and length of your CR (to hard walls) and running a modal analysys on it, I'm not sure if you'd need any specifically targeted traps - in most cases, broadband doesn't color the sound nearly as much. Kind of like EQ - you can sometimes get away with a sharp notch, but when boosting it better be low Q unless you're "firing for effect"... Also, the overall room treatment needs to be considered as a complete system so you don't end up with drastically different reverb times at different frequencies - so you have to consider ALL your treatments as a whole and calculate absorption coefficients in order to find out if you're going to be "in the ballpark - this is a fairly tricky area that I've NOT gotten into in any depth yet - it includes factoring in the panel trap effect of whatever wallboard you use, spacing of studs, flexibility of studs, carpet, furniture, ceiling paneling/trap effect, floor resonances, and probably a dozen more I've neglected. If your room was really large, you'd even need to include the hf absorption of AIR. OTOH, Everest made the comment in a few of his books that he didn't bother with other than axial modes, because the minute another person or piece of gear is added it changed things. To keep things in perspective though, he's also NOT a proponent of non-parallel walls - Part of that may be due to his generation's lack of access to computers, or just working with what he knew, etc... Not sure if this was help or hinder, but I think it just confused ME more than usual... Steve