I fixed your previous post by quoting and double-quoting the various bits or text, to make it clearer and easier to follow.
You can do that yourself: To quote text in your reply, just select it with the mouse then hit the "quote" button at the top of the panel where you type in your reply. Makes it easier to follow.
I WOULD LIKE 63DB OF ISOLATION.
I'm curious why you came up with that exact number... Why not 60 dB, or 70 dB?
But anyway, 63 dB is not an easy task. I already mentioned that STC-63 is not the same as 63 dB (not even close!). It's not so hard to get STC-63, but it is hard to get 63 dB of transmission loss. It's not impossible, but it is a tall order. You are setting your goals high. Nothing wrong with that! But I do want to mention that what you are asking for is not a walk in the park...
WATER HOOKUPS ARE 18K SO NO WATER LOUNGE ETC...
OK, got it! Makes sense...
THESE ARE 18FT WALLS. THE STRUCTURAL ENGINEER SAID 2X6'S
Ahhh! OK. Makes sense. I missed the note on the height. Check with your engineer: you might be able to go 24"OC with that, instead of 16"OC. Save a few studs like that.
WOULD THAT INCREASE THE NOISE TRANSFER IN THE OUTSIDE LEAF OF THE WALL?
Nope. Not a problem.
BUT DOES RIGIDITY HAVE SOMETHING SOUND TRANSMISSION THROUGH THE WALL? AGAIN INNER WALLS ARE 16 FT OR SO.
You might not be able to use 2x4's then. You can normally only do 12', or maybe 14' with 2x4s, depending on code.
Yes, rigidity is related to sound transmission through walls, but it's not a simple relationship. Different frequencies do different things to different characteristics. It works more or less like this:
four-regions-of-isoaltion--transmission_loss.gif
So rigidity (stiffness) does have an effect, but only at frequencies below the MSM resonance of the wall. If you tune the wall system properly, then that will be sub-sonic, so not really a problem. For a well-designed isolation wall, it's the tuning that maters, not so much the stiffness. (the above graph is actually for a single leaf wall: for a 2-leaf the entire curve rises faster and slides over the the right a bit, but the regions are basically the same).
THE CEILING IN THE CONTROL ROOM WAS TO BE SPLAYED FROM 9-12 FT FROM NORTH TO SOUTH.
The angle is not large enough to be useful. It needs to be at least 12 degrees to deal with flutter echo, and much more than that to create a proper RFZ. Ditto for the wall angles.
LIVE ROOM 15-17FT FROM SOUTH TO NORTH
Ditto. Not a large enough angle to be useful for flutter echo. I would re-think that.
OK SO THE INNER WALL STRUCTURE SHOULD HOLD THE CEILING. CAN ONE WALL BE TALLER THAN THE OTHER TO SPLAY THE CEILING?
Yes, and yes, but there are caveats in there, especially if you go over about 12'. Normally you'd do a double top plate at 12', then stack another section on top of that. But that's getting ahead of where you are. Framing a tall structure is not as easy as framing a more typical 8' or 10' 2x4 structure.
MY DRAWINGS ARE NOT EXACT BUT THE IDEA WAS RFZ WITH AVERAGE ROOM DIM BEING 19x14x10 or 1:1.4:1.9
Your drawing does not show RFZ at all! RFZ needs much larger angles at the front of the room to re-direct the first reflections around the mix position, well clear of the engineer's head: You can't do that with small angles, nor with absorption. Here's a link to a thread about a studio that I designed for one of my customers:
http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471
That is a true RFZ-style room. The entire sweet spot is free from first reflections: And you can see the large angles on the front part of the side walls (or the side parts of the front wall, if you prefer that perspective!), as well as on the ceiling cloud. In order to create the RFZ, you need large angles, and you also need soffited speakers (flush mounted). As you can see from the acoustic analysis graphs, when done properly, it works extremely well.
THE ROOM IS SHOULD BE SYMMETRICAL WITH THE ANGLES ETC.
The shell might be symmetrical. but the interior of the room is not. There are "things" that I'm assuming to be racks, cupboards, chairs, gear, or furniture of some type that are upsetting the symmetry. And symmetry is critical for a high-quality control room. Your left ear must be hearing the exact same acoustic signature as your right ear, or else your mixes will be "skewed". In the room I linked to above, there is less than +/- 1dB of difference between the left and right sides of that room, across the entire spectrum, 17Hz to 21 kHz. That's the type of extreme accuracy you can get in a well designed, well built, and well-tuned room. But you can't do it if you have large differences in basic symmetry.
IF I MADE A RECTANGLE WHAT WITH WOULD YOU SUGGEST?
If you made a rectangle, it wouldn't be RFZ either!
In my opinion, RFZ is the best possible design for a room, but it cannot be done with rectangular rooms. The basic premise of RFZ is that there are angled surfaces at the front of the room that force the first reflections away from the head of the engineer, redirecting them into the side and rear walls, where they are absorbed/diffused, before eventually coming back the the engineers ears as a low-level diffuse reverberant field that is at least 20 dB down from the direct sound, and also delayed by at least 20 ms. That's part of the definition of what an RFZ room is, and the way to attain that is to steeply angle the front parts of the side walls enough to do that: The rest of the side walls can be splayed less steeply, or can even be parallel, but the front parts need steep angles. Ditto for the front part of the ceiling: it also needs to be angled steeply, or there needs to be an angled cloud hung below it, hard-backed.
What you show in your diagram is not an RFZ room. The wall angles are way too shallow, and the rear-end treatment is wrong.
THAT IS MY ERROR IN THE DRAWING. SORRY
Not really... for a true RFZ room, the speakers should not even be in the room at all! Rather, they should be flush-mounted in the angled sections of the front wall, which is often referred to as "soffit mounting". Once again, refer to the above linked thread.
BASS TRAPPING WOULD BE IN THE REAR CORNERS ETC. I HAVE SOMEONE WHO IS HELPING ME WITH THAT
That would not be enough for that room. In order to get perfectly neutral acoustics (such as you see in the graphs on that thread above), you need major bass trapping. What you can't see in those photos is the huge amount of bass trapping that went into that room. There are large, deep superchunk-style traps arranged both vertically and horizontally in the walls, as well as several feet of bass trapping above the visible ceiling, acoustic hangers all across the front of the room inside the soffit modules, and membrane traps and poly-cylindrical diffusers on the rear upper and walls, respectively. Your room would be about the same size as that one, so it would need similar trapping. A couple of small things in the rear corners is not going to cut it. Sorry.
I WAS LOOKING FOR A LARGER CONTROL ROOM TO HAVE SOME PERFORMERS ACTUALLY PLAY IN WHILE THE DRUMS WERE IN THE OTHER ROOM. THERE WOULD BE TREATMENT DIFFUSION ETC.
No problem at all with that, but you are missing the point I was making: The client couch is
up against the rear wall,
where there will be terrible bass build-up. That's a terrible position for the client couch! That's where the producer, client, musicians, etc. will be sitting while they listen to your mix. If the couch is up against the rear wall, which is also untreated, all they will hear is the loud mushy boomy thumpy thuddy mess of the deep bass, totally out of whack with the mids and highs... it will sound awful.
My point is that the couch needs to be several feet forwards from where you show it, well out of the SBIR zone, and with several feet of deep bass trapping on the back wall. Take a look at the smaller photo lower down in that thread above: the client couch is about 9 feet away from the back wall, and even then it took a couple of days of careful tuning to get the response smooth for that position.
THE PLAN WAS TO SCOOT BACK A BIT AND LOOK OVER OUT THE SLIDING GLASS.
Wouldn't it be a lot easier to just position the glass at a location where you don't have to do that?
There's no reason under the sun why you could not do that: you have plenty of wall space, just begging to be used more effectively...
I WAS TRYING TO KILL 2 BIRDS WITH ONE STONE AND ONLY HAVE ONE ENTRANCE AND STUDIO WINDOW COMBINE.
I would really, really suggest that you add a small entrance lobby, where people )including yourself) can hang their jackets, wipe their feet, leave their wet umbrellas, dump any stuff they are carrying such as instrument cases, food, drink, etc. Then have individual doors to the rooms coming off that lobby. Even put an easy chair and a mini-fridge in there, so they can relax and chill out in peace while the session carries on in the actual studio area. It would take up a few square feet, sure, but the utility far outweighs the small amount of "lost" area. Without that, people will be wiping the mud and dirt of their feet and hanging their wet cloths in the Live Room, thus messing up the tuning of the musical instruments and the tone of the condenser mics, due to the sudden overload of humidity in the room... It's far better to have that small "buffer" room to protect your gear, instruments, and the studio itself.
Sort of like your vestibule, but re-arranged so it butts up against both actual studio rooms, with doors to each...
DO I NEED AN INTERIOR DOOR? SORRY CONFUSED HERE
I should have been more clear about that comment: what I meant to say is that the vestibule construction as show creates flanking paths that couple the LR inner-leaf to the outer leaf, and since the vestibule is technically part of the outer leaf, yes, it does need another door on there, and another leaf.
OK. YOU HAVE MY ATTENTION
The best way to get good levels of isolation at low cost is by using the "fully-decoupled 2-leaf MSM isolation" method. That means that you have a cavity inside your walls that totally separates the two leaves. The same applies to the ceiling: also two-leaf with a separating cavity. If you were to put something inside the cavity, such as random times that you want to store for a while, then you are re-tuning the MSM system, and changing the isolation properties. Most likely for the worst...
Secondly, if you want to store stuff in there, then you'd need some type of access door or hatch into the cavity. That means you'd have to build that just the same as all the other isolation doors, with very high mass, multiple seals, over-size hinges, etc. An awful lot of work just for a storage area!
Thirdly, your HVAC ducting and silencer boxes need to be in thee cavity, if you want to make efficient use of space. Those will be BIG! The key to silencing the HVAC system is to move a lot of air at very slow speeds, instead of a bit of air at high speed. To move enough air at the speeds that are allowable for studios (under 300 FPM, and preferably around 100 FPM), you need very large vents and ducts. And to keep the sound in while allowing the air to move through, you need very large silencer boxes. You can either put those inside the rooms, where they take up a lot of space, or inside the ceiling and wall cavities, where they don't.
If you want, I could send you some images of typical HVAC systems that I have designed for my paying customers, but I would have to do that off-line, not in public, as I don't have their authorization to put their studio details out in public. PM me if you'd like to see some of those.
SO YOU ARE SUGGESTING I RE ARRANGE THE ROOMS AND HAVE A CONVENTIONAL STUDIO WINDOW? $$? THEN A DOOR AS WELL WITH OR WITHOUT AN AIR LOCK?
Not really. I guess I didn't explain that too well! What I was trying to suggest was that instead of buying very expensive sliding glass doors, you could build conventional hinged doors that have large glass panels in them. It would be much cheaper, and just as good. When you open a sliding glass door fully, you have less than half the width as actual open area. A hinged door can actually provide you a wider opening that a sliding glass door... Better for getting gear through... It's not that hard to site-build such doors. Once again, I'd be happy to show you examples off-line.
THANK YOU....I NEED TO STOP DRUMS FROM COMING THROUGH THE WALL. ANY IDEA HOW MUCH I NEED?
I wish it were as easy as saying "You need 61.384 dB TL to do that", but it isn't. It is all relative. Let me explain:
If you are playing your drums at 100 dB in a typical house in a noisy city suburb, then you might only need 40 dB of isolation to keep your neighbors happy, as the ambient noise would mask the drums. Move the same scene out to the countryside, and you might need 50 dB of isolation, because there is a mot less ambient noise to mask the drums. But move that into a studio, and the question becomes: how well isolated is the studio? The better the quieter it is inside, the more noticeable the drums will be even when well isolated. Let's say you get your CR is at NC-35, and your drums are at the same 110 dB level in the next room. You'd need about 65 dB of isolation to get them to the point where you can barely hear them. But if the same CR is actually NC-15 (instead of NC-35, which is noisy for a studio), then you'd need more like 75 dB isolation.
In all four cases, we have the exact same drums and drummer, playing at 110 dB, but in the best case you only needed 40 dB to make them inaudible, while at the other extreme even ten thousand times more isolation did not do the trick: (Yes, 70 dB really is ten thousand times the isolation of 40 dB. It blocks ten thousand times more sound intensity...).
That's why I can't give you a simple answer: because the question is not as simple as it looks. The quieter you get your studio inside, the higher the level of isolation you would need between rooms. That's one reason why modern office buildings are specifically designed to have "noisy" HVAC systems, where the air noise has a specific signature that masks typical office sounds really well. So you can't hear the guy at the nest desk talking on the phone. The NC-rating is very high, on purpose. But for a studio, to needs to be very low.
And of course, the more isolation you need, the more expensive it gets. It goes up exponentially, because the decibel scale is also exponential (logarithmic, to be more accurate): The very best isolated studio on planet earth gets about 100 dB of isolation, and cost millions of dollars to build. That's Galaxy Studios, in Belgium. Each room consists of a hugely massive concrete bunker inside another hugely massive concrete bunker, resting on massive steel springs with neoprene pads. And even then, it does not isolate perfectly: you can easily hear a gunshot in the next room. Heavily muffled, but audible.
So that's the 64,000 dollar question: what level of isolationism should you design for? 50 is relatively easy to do, 60 is quite a bit harder, 70 is really tough. 50 is easily in range of a budget in the tens of thousands of dollars, while 70 would need a budget with an extra zero on the end...
I would suggest that you shoot for 60-something. That's probably about as high as you can go in your case. Drums will still be vaguely audible in the next room, but very dull, muffled, soft, and distant.
I MIGHT BE ABLE TO USE 2 AND FOR THE NEW STRUCTURE AND DO THE OLD CR IN PHASE 2 OF THE PROJECT.
That would work.
I HAVE BEEN DEBATING OVER THIS AS THE RAMP WOULD BE ABOUT $1500 OR SO
The ramp would not need to be concrete: You could do a nice wooden ramp for less money that that. Or maybe a stone ramp (rocks) with just a bit of concrete for the surface.
ANY ADVISE ON METAL STUDS FOR THE 18FT WALLS?
It might be possible. I don't work much with metal studs. Most of my designs are for wood. But you might be able to go higher with metal than you can with wood, Your structural guy can probably answer that.
THANK YOU. WILL FOLLOW UP.
Looking forward to following your build, whichever way it goes: It's a really nice large space, with great potential and a decent budget. It has the makings of a fantastic place, if designed carefully and built carefully.
- Stuart -