so I have an good idea of what to expect and where mix position will be
Actually, it's far better to determine that position acoustically, rather than try to do it by ear. In other words, use the math and empirical data to set the mix position where it really will be the best, not just where you think it might be from past experience. Every room is different, and each needs it's own design and treatment, based on the actual acoustic response, not deductions, extrapolations, or guesswork.
Case in point: This room :
http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471 was originally designed based on past experience, but when the owner figured out it was not working the way he expected (from past experience), he brought me in to fix it. I had to make some drastic decisions, and completely re-design the entire interior, and he had to take down some parts that he had already built, then rebuild everything. Fortunately, he trusted me to do that, and is now extremely happy that he did.
where mix position will be and of course I what is shown in the drawing is NOT it.
For sure!
with a architect who has no clue what any of this is. I drew the basics on graph paper and had him create construction docs for city permitting. I was only concerned with the basic shell / layout at that point.
Just the exterior shell, or the inner-leaf as well? There are issues with both of those, but not major ones, fortunately, on the outer-leaf.
I was under the impression a corner is a corner.
Welll.... yes, but not really. A corner can only treat the modes associated with the surfaces on either side of it. It cannot possibly have any effect on a mode associated with another surface. So a bass trap in the rear-wall to ceiling corner will have zero effect on the modes associated with the side wall. Bass trapping in the vertical corners will certainly do that. Of course, bass trapping in the vertical corners won't treat modes associated with the ceiling, but those will be dealt with in other ways in any case, so it's not really an issue.
I plan to put a huge bass trap soffit, bigger than any I could fit in a corner in the upper ceiling corner running the width of the room.
That would help with rear-wall modes and modes in the vertical axis, but won't do much for axial modes running across the room, between the side walls, nor for tangential modes involving those walls, nor for any oblique modes.
But with a 12' ceiling height I have alot of space to work bass trapping into via hangers, membranes ect. I've worked in plenty of sonically amazing rooms that addressed bass trapping in this fashion vs huge corner traps. I realize some will think its foolish but Ive experienced it in real life and I know it works.
Not trying to be negative or demeaning, but once again, all rooms are different, and what might have worked in a other room in the past won't necessarily work in this room. For example, if you had treatment in another room for a mode at 130 Hz (hypothetically), and this room does not have a mode at 130 Hz but does have one at 120 Hz, then you would be treating a problem that does not exist, and failing to treat the one that does. That's a very simplified example, of course, but hopefully you get the point. Ditto for the mix position: if you happen to have set up the mix position in another room that had an SBIR cancellation at 85 Hz and a floor-bounce at 120 Hz, but in this room the primary SBIR null is at 77 Hz and the first floor-bounce artifact is at 116 Hz, then placing the mix position in the same relative location here would be a mistake.
Every room is different, and the layout, geometry, and treatment should be planned accordingly, based on the equations, specs, and predictions.
I will be using the Overly Door STC 55
Firstly, you should NEVER use STC when designing a studio. It is no use at all for telling you how well your studio door (or any other part) will isolate. STC was never meant to measure such things. Here's an excerpt from the actual ASTM test procedure (E413) that explains the use of STC.
“These single-number ratings correlate in a general way with subjective impressions of sound transmission for speech, radio, television and similar sources of noise in offices and buildings. This classification method is not appropriate for sound sources with spectra significantly different from those sources listed above. Such sources include machinery, industrial processes, bowling alleys, power transformers, musical instruments, many music systems and transportation noises such as motor vehicles, aircraft and trains. For these sources, accurate assessment of sound transmission requires a detailed analysis in frequency bands.”
It's a common misconception that you can use STC ratings to decide if a particular wall, window, door, or building material will be of any use in a studio. As you can see above, in the statement from the people who designed the STC rating system and the method for calculating it, STC is simply not applicable.
Here's how it works:
To determine the STC rating for a wall, door, window, or whatever, you start by measuring the actual transmission loss at 16 specific frequencies between 125 Hz and 4kHz. You do not measure anything above or below that range, and you do not measure anything in between those 16 points. Just those 16, and nothing else. Then you plot those 16 points on a graph, and do some fudging and nudging with the numbers and the curve, until it fits in below one of the standard STC curves with only a certain number of "defects". Then you read off the number of that specific curve, and that number is your STC rating. There is no relationship to real-world decibels: it is just the index number of the reference curve that is closest to your curve.
When you measure the isolation of a studio door, you want to be sure that it is isolating ALL frequencies, across the entire spectrum from 20 Hz up to 20,000 Hz, not just 16 specific points that somebody chose 50 years ago, because he thought they were a good representation of human speech. STC does
not take into account the bottom two and a half octaves of the musical spectrum (nothing below 125Hz), nor does it take into account the top two and a quarter octaves (nothing above 4k). Of the ten octaves that our hearing range covers, STC ignores five of them (or nearly five). So STC tells you nothing useful about how well a wall, door or window will work in a studio. The ONLY way to determine that, is by look at the Transmission Loss curve for it, or by estimating with a sound level meter set to "C" weighting (or even "Z"), and slow response, then measuring the levels on each side. That will give you a true indication of the number of decibels that the wall/door/window is blocking, across the full audible range.
Consider this: It is quite possible to have a door rated at STC-50 that does not provide even 30 decibels of actual isolation, and I can build you a wall rated at STC-30 that provides much better than 40 dB of isolation. There simply is no relationship between STC rating and the ability of a barrier to stop full-spectrum sound, such as music. STC was never designed for that, and cannot be used for that.
Then there's the issue of installation. You can buy a door that really does provide 50 dB of isolation, but unless you install it correctly, it will not provide that level! If you install it in a wall that provides only 30 dB, then the total isolation of that wall+door is roughly 30 dB: isolation is only as good as the worst part. Even if you put a door rated at 90 dB in that wall, it would STILL only give you 30 dB. The total is only as good as the weakest part of the system.
So forget STC as a useful indicator, and just use the actual TL graphs to judge if a wall, door, window, floor, roof, or whatever will meet your needs.
When a manufacturer specifies performance of studio materials in STC, be very, vary careful. Get the actual TL data from them, and use that to check that it will perform the way you need it to perform. If the manufacturer cannot (or will not) provide you with actual test reports of their products, measured in certified, reputable, independent acoustic lab, then it is safe to ignore that manufacture and find another who does actually trust their own products enough to get them tested, and to show the truth. STC is a feeble crutch that some manufacturers lean on when they don't want to reveal the true performance of their stuff.
Not surprisingly, the data supplied for the door you mention only covers the STC range. So as long as you don't need good isolation below 125 Hz or above 4 kHz, then that door would be OK... but considering that around 80% of the energy produced by a typical contemporary band is below 125 Hz, you probably want something a little better than that... That's where your kick, toms, snare, bass, low end of electric guitars, keyboards, and many other things are putting out stacks of energy...
I think a double door in this situation would be redundant.
I don't!
Simple question: You have a two-leaf wall, yet you want to use a single door: How will you put that single door into BOTH leaves, without tying the leaves together?
Think about that. The answer is that you cannot. It is impossible. Anything you do to the leaf that does NOT have a door in it (to seal it up and maintain the surface density), will create a flanking path that joins the two leaves together. As you probably already know, with two-leaf construction, the leaves must absolutely not be permitted to touch each other at any point, not eve a single nail, since doing so trashes the isolation. If you have any connection between your leaves, then you wasted a hell of a lot of money on building the two-leaf system, since connecting the leaves in any way destroys most of the isolation.
Illustration: If you can get your hands on an old-fashioned tuning fork (what musicians used to tune their instruments, years ago, before digital tuners) then tap the tines on a hard surface and hold it up in the air at arms length. That's how much sound can be transmitted through air without any mechanical coupling. Now tap it again, and set the base down on the desk or table in front of you: that's how much sound can be transmitted by a single nail that connects your two leaves.
Convinced?
You clearly need serious isolation for this studio, since you want monster speakers and want to play loud. The speakers you are talking about go way down into the low 20's, so you need to design your MSM isolation system such that the resonant frequency is around 10 Hz. I'm not sure if you have done that yet (probably not), but when you try, you'll find out just how hard it is to do that, and you'll see why it is critically important in your case that the leaves cannot be permitted to touch: no connections at all between them.
I also HATE double door studios, rarely gets executed in as clean as a single heavy properly manufactured acoustic door.
That's a construction problem from poor workmanship, not due to any inherent problem with double doors.
Here's some photos of the doors on the studio I designed for one of my customers in Australia. These are site-built doors, constructed by a good carpenter who cares a lot about about detail, and carefully followed my design and my instructions on how to build them:
Site-built-door--BRAUS--102+--door-blank-cut.jpg
That's the basic solid door blank, with the hole for the window cut out.
Site-built-door--BRAUS--106+--all-layers.jpg
There you can see all of the layers of the door in the jig, being glued and screwed together.
Site-built-door--BRAUS--109+--frames-shimmed-and-squared-2.JPG
The two independent frames in position, one in each leaf, plumbed and squared.
Site-built-door--BRAUS--112+--inner-door-hung.jpg
Inner door hung, but without the seals on it yet (except for the drop-down seal that you can see in the base of the middle layer of the door)
Site-built-door--BRAUS--114+--both-open-seals-and-gap.JPG
Both doors hung, and with all three full-perimeter seals in place on the inner door.
Site-built-door--BRAUS--115+--Finished-Entry-door-from-outside.jpg
Completed door system, seen from outside.
Site-built-door--BRAUS--116--Finished-Entry-door-from-inside.jpg
Completed door system, seen from inside.
Site-built-door--BRAUS--117+--both-open-from-outside.JPG
As seen from outside, with both doors open.
That setup gets a little better than 60 dB TL. Way superior to what your STC-55 door can do! If you wanted a single-leaf door to give you 60 dB of isolation, it would have to have a surface density of 524 kilograms per square meter (a little over 107 pounds per square foot). Do the math yourself if you don't believe me. Use the Mass Law equation, which is what applies to single-leaf barriers. You'll need to use the version for high-mass systems, not low-mass systems, or you'll get ridiculous results.
This customer has a neighbor about 5m away (15 feet, roughly), with no fences or barriers in between. Just a direct line. The neighbor hears practically nothing at all, even when it's really loud inside the room. That would be practically impossible to achieve with a single-leaf door.
That door will be for a small amp closet.
ummm... an amp closet in your MSM air gap?
I can't see that working very well at all!!! How on earth will you ventilate and cool something that is inside your MSM air space, without trashing your isolation, considering that the basic principle of MSM isolation requires absolutely air-tight seals on both leaves? There can be no air circulating in the MSM space. It mus be hermetically sealed on both sides, or you don't get isolation. The principle is simple: it air can get through, then so can sound...
Major problem.
and I dont like amps in the control room bc of the heat they introduce
Absolutely agree! So build a proper machine room for your amps and other noisy, hot gear, some place in your studio that makes sense! It doesn't need to be very big (just fit in one 40R rack, with space to get around the back), and it can double as your HVAC AHU closet, and also your electrical closet, and perhaps even for storage too, if you make it a bit bigger.
I choose these dimensions bc I want a focused sweet spot in the mix position.
That's probably a mistake. Either that, or "focused" was not the word you wanted!
The sweet spot should be as broad as possible, covering as large an area as is feasible. A focused sweet spot limits your engineering position to a very small area.
Many people think that the speakers create the sweet spot, but that's only partly true. In reality, it's the room that creates the sweet spot, with help from the speakers. It's a system.
Did you do any acoustic ray tracing to ensure that you get no first-order reflections in any part of the sweet spot, within 20ms or at levels higher than -20 dB below the direct sound? If so, then please mark on the drawing the extension of your sweet spot. I have a feeling it's not as focused as you want it to be, and it certainly isn't where the desk is right now! (But you already knew that... )
This is my personal mix room that only selected clients will be in so I didnt want wider angles focusing music more toward the rear of the room. Im selfish and wanted the mains set up for me
OK, so you DID mean "focused" in the sense that I suspected! And that is a mistake... Sorry to be so harsh and in-your-face, but designing a large, expensive room like that with a tiny sweet spot, greatly limits the acoustic response and flexibility and overall effect of the room. You should probably take a look at ITU BS.1116-3, or EBU Tech-3276, to understand what a critical listening room really needs to be like, for maximum performance. If your room does not meet those specs, then you have a problem: It is not a critical listening room, which is sort of what control rooms have to be!
Having the speaker axis intercept too far forward will distort your sound-stage and stereo imaging. The best place for that is around 18"
behind your head, in most studios the size of yours, maybe a bit more. That will produce a broad, balanced, even, smooth sweet spot that is large enough to allow for good engineering, even if you want to use a large format console. As nice by-product, it will also proved pretty decent coverage for the client couch at the rear of the room, such that they will be hearing more or less the same as what you are hearing. If each person in the room hears something different, then the room is very poorly designed, and your musicians will not be happy when listening to the playback mix. They'll be arguing about who did what wrong, when you at the mix position think it sounds fine! Or even worse, you at the mix position will clearly hear a problem with someone's performance but they won't be able to hear it, and will be rather upset that you are a "falsely" accusing them...
A basic design goal for a control room is that everyone should hear the same sound, as close as physically possible. In Studio 3, when we were doing the final tuning, I discovered an issue at the client couch location with uneven bass response, so I added another sub and re-tuned everything to fill in that defect, without affecting the rest of the room. So now the mix position and the client couch have pretty much the same response: No agreements, finger-pointing, or disagreements, since everyone hears the same thing. In fact, even along the sides and at the back of that room, there's no major differences in response. It is smooth and even throughout.
The 215H is the box I am using,
OK, cool. At least I have something to go on now. So a pair of 215H's, plus a pair of TAD 1801's, mounted in .... ??? what box?
Man I can't tell you how loud exactly lol, but this I can tell you, just as sure as the sun comes up, my clients WILL turn the volume knob as loud is it will go
Yup, I sure do know what you mean! Which is why you w0ll probably want to put some type of limit on how loud they CAN go.
and my room will be tuned and it will sound AMAZING when they do!
Ummm.... that would be a major mistake. Big-time major! Control rooms should NEVER be tuned to sound good. They should be tuned to sound flat! That's the entire point of having an amazing control room with amazing speakers. It must sound totally flat at all listening levels. Take a close look at ITU BS.1116-3, to see what makes a control room "great".
The entire reason why a control room exists is so that the engineer can hear exactly what is in the mix, perfectly clearly, crustal clear, pristine, sound, not colored in any way by the speakers, or the room, or anything else. The response must be ruler-flat (see the response graphs for the room I linked you to above), with perhaps a slight house curve, such as the famous B&K curve, to reduce ear fatigue and enhance long-session listening accuracy.
If the room does not tell the full, ugly FLAT truth, in all aspects (frequency, time, and phase), then the engineer will not be able to easily produce mixes that translate perfectly. It's that simple. Tuning a room to "sound good" is always a mistake, and unfortunately it's a common mistake made by first-time studio designers. Then they always wonder why the room just does not turn out good mixes that translate wonderfully to all other platforms, when the room sounds just so cool!
It is supposed to sound flat, neutral, boring, precisely because yo need to make your
mixes sound great. If they sound great anyway because the room is enhancing them, then you have a problem...
Ive been at it day in and day out for over 10 yrs and I know when to use ear plugs
Your speaker setup can easily put out levels well in excess of 120 dBC. At that level, NIOSH says you have about seven and half minutes until you suffer permanent and irreversible hearing damage. I'm not sure if you are aware of that, but it's the reason why so many musicians want to turn up the sound to eleven in the first place: because they are already deaf, and really can't hear anything quiet...
my clients could care less about the future / safety they wanna hear their music BANG
Yup! Like I said, you don't see too many hip-hop or rap artists in their 50's and 60's.... Even big-name rock and pop artists have the same problem. Rumor has it that Phil Collins no longer tours much, because he's too deaf to hear what he is playing on stage these days, and can't hear his band.... They have to follow him, because he can't follow them...
You're right about that but when I'm mixing I don't mix loud and I take breaks every 15 to 20min as not to loose perspective over what Im doing.
Smart move! Somewhere I have a research paper about hearing tests conducted on the musicians in a symphony orchestra, and the findings are quite amazing (but not surprising, if that makes sense). I don't recall all the details, but one I do remember it is that all of the violinists were deaf in their left ears, but had decent hearing in their right ear. You only have to look at where a violin sits in relation to your left ear when played normally, to understand this. Not surprisingly, most orchestra conductors do NOT have hearing problems, since they are located quite a distance away from where all the noise is generated, up on their raised platforms, and often with a music stand, podium, or "pulpit" of some type, protecting their ears from direct sound coming from the first rows of musicians. It was quite an interesting read... I'll see if I can find it.
So in system 1 you are talking about squeezing the speaker cab into a rubber lined soffit box?
Not really, no: you squeeze the speaker cab into a massive wooden box that is NOT lined with anything! Just the wood box itself, gripping the entire cab like life itself depends on never letting go. To my way of thinking, that's not a nice way to treat an expensive piece of delicate, precision gear: Forcing it into the box puts stresses and strains on the cab itself that can weaken or damage it structurally and acoustically, and at the very least, scratch it! Studio reference monitors are not FOH live performance speakers, and are not built to take that type of punishment. They are solid and robust, yes, but still, the idea of shoving and thumping a precision device to make it fit in a tight space, just does not sit well with me. That's why I design most of my soffits with the "floating" approach: it treats the speaker gently, delicately, the way to should be. I have great respect for precision engineering that goes into multi-thousand dollar speakers, so I'm not inclined to take a hammer to it, to force it where it does not want to go!
Now, that's just me: other studio designers don't seem to mind doing that... personal choice, I guess.
There's also the issue of resonance: since all objects have one or more natural resonant frequency(ies), shoving the cab in a box produces an object that has just such a set of frequencies... so how do you stop those getting into the soffit structure? Good question.. I've never heard a satisfactory answer.
...and that should be sufficient enough if it the tolerance is tight enough?
That's the theory, yes, but I don't buy into it very much. Letting the speakers float within a precision suspension system that is carefully tuned to allow the speaker do what it does best across its full spectrum, without transferring any of that energy into the soffit structure, just seems to be the logical and sensible approach. It has worked wonderfully in ever single room where I've used it. Of course, it does require careful design, and lots of calculations, to ensure that it really does float across the entire spectrum of the speaker, with no unwanted resonances.
- Stuart -
.... 