However the biggest problems here are the sound blasts from the Studio and CR every time someone goes between rooms. A small air lock to the studio probably helps a little, and the CR could have a "dim" switch that attenuates the monitor amp every time the door opens... but the ingress/egress is inelegant...
Can you move your doors on the CR outer leaf wall? I see you have two doors there, one of which will be blocked off. I'm guessing those are existing doors in the building itself? I would suggest just moving one of those to roughly the middle of the CR right side wall.
Compare to my best design for the north facing design:
There's lots more problems with that, to be honest! The East facing design is better.
the sliders to the left of the CR lead into the lounge, which will not blast sound leakage to the hallway either.
With the East facing design, you could also have doors in the rear wall. Not ideal, but possible with careful design.
On the other hand, you could just put sliders across between your speaker soffits, in the middle of the front wall: that gives you easy access between LR and CR. Simple, effective. Great sight lines, and you can still get good isolation.
I'm not sure you know this, or would agree, but the best and most experienced guys in this biz know how to pull great sounds in imperfect rooms. Certainly a lot of the guys I know of.
Sure you can! A good engineer can mix in a not-so-good room... But it is more tiring than mixing in a good room. There's more mental effort involved in "ignoring" the defects in the room. Even though it is mostly subconscious for an experienced engineer, it still takes effort to "listen through" the poor acoustics. So why make your life more difficult and more tiring? In a great room that only tells you the absolute truth, it is easy to get mixes that translate well with less mental effort, less fatigue. It's rather like the old original LEDE rooms: they were accurate for mixing, but mentally very fatiguing because the sound was not natural or pleasant. Hence, all those more recent modifications to and extensions of the LEDE concept, to keep the good part and get rid of the bad part, creating rooms that are even more accurate, but without the negative fatiguing.
So, absolutely, the best engineers can mix in a less than stellar room... but the average engineer can't...
Either way, the new guy advises that I should still put a 60mm high floating floor in the CR and suspend an RC ceiling taking up 80mm space.
For what reason, with regards to the floor? Assuming you'll be mixing at sane levels, around 80-85 dB, and the room is correctly treated, you might be able to get away without it. Yes, it would be better to fully isolate your CR with a properly floated floor, but you still have your building floor loading limit problem: that floating floor in the CR will add mass, which you will then have to subtract from the LR mass...
I do agree with the ceiling, though: you do need some type of isolated, decoupled ceiling up there.
He claims any resonance is soaked up by the 60kg/m3 insulation.
The purpose of insulation in a decoupled wall (floor, ceiling) is many-fold. Yes, one thing it does is to damp resonances, and there are multiple types of resonance potentially going on in there. The MSM resonance is only one of those, and no, it will not "soak it up" completely. That would be impossible. At best, really good insulation might be able to knock off 20 dB from the resonance (0.9 coefficient). The theoretical limit is about 0.95, which aprox. 27 dB, so you can never have more than 27 dB reduction in resonance, even if you had perfect absorption. But of course there are no "perfect" absorbers anyway that attain the theoretical limit, and 60 kg/m3 insulation is far short of perfect...
The other things that insulation does, is to slow down the speed of sound, which is why the cavity should be completely filled, for maximum effect (despite some misguided statements from so-called "experts" who should know better): The lower c in the cavity also makes the cavity "seem" deeper by a factor of up to 1.4 (roughly), so the sound waves "think" they are traveling though a distance that is 1.4 times greater than what it really is. And the insulation also changes the way that air deals with heat, from adiabatic cooling to isothermal cooling, which obviously makes it more efficient at removing the energy from the compression phase of the sound waves, instead of just returning most of it in the rarefaction.
So you have all of those going on at once: If he thinks that all the insulation does is to "soak up MSM resonance", he is sorely mistaken. Which is why it is so important to choose the CORRECT insulation for the job....
BTW, he has since confessed that the fibre wood (canite) part of the sandwich doesn't get used any more as he's never been convinced it is worth the expense or the 13mm space.
Well that's interesting! So his "perfect and proved in a thousand studios" sandwich, isn't so perfect after all!
How surprising...
Which leads to the obvious next question: what OTHER parts of his method don't work, are are not effective? What other materials might he eliminate, add, or modify in the future, as his mood changes? How would he ever know which parts work and which don't, if he never had his sandwich tested, nor any variations of it? "Not being convinced" about something doesn't seem like a good way of designing a multi-thousand dollar isolation project... Is there a money-back guarantee if you don't actually get the 85 dB isolation he is promising you?
He's not a fan of the "inside out" module, not just because of extra materials and expense, but more so because he feels 450mm centres (not 600) is a critical part of his stiffness-centric approach...
Whooaaa!!! Hang on a sec! So he wants his walls to be MORE stiff, not LESS stiff, in order to get his isolation to work? Ummm.... he seems to be a little confused. What I was talking about yesterday, in relation to stiffness, is to use LESS stiff products for those ranges I mentioned. That is what maximizes isolation! Reducing stiffness raises the frequency of the coincidence dip, and raises the dip itself. The best isolation comes from high mass and low stiffness. This is why materials like lead and MLV provide high isolation; they are "limp mass": high mass, low stiffness: they have no coincidence dip at all!
Simple demonstration for yourself: pick up any acosutic guitar you happen to have around, and pluck a string: any string. Now increase the stiffness of that string, by rotating the tuning peg to make it tighter: the tone goes up (duh!). Now do the opposite: REDUCE the stiffness by rotating the peg he other way... and keep on going as you loosen, pluck, loosen, pluck... the less "stiff" the string, the lower AND QUIETER the note... sooner or later you'll get to the point where the string is "limp": not stiff at all... and no longer makes any sound.
QED.
If you want better isolation from a wall, you INCREASE the stud spacing from 400mm OC to 600mm oc (16" to 24"). That LOWERS the resonant frequency, and improves isolation. Check out IR-761, if your guitar didn't already convince you. There are several examples of otherwise identical walls performing better at 600 OC than 400 OC. Those are real world real walls actually tested in real acoustic labs: no fairy tails and "not too convinced it does anything useful"...
Hooo boy....
The other bombshell relates to the deflection of the mounts supporting the floating floors. He said I could always add more mass to the floor after the fact, even as much as double, without upsetting the working deflection range of the Embleton "blue" rubber mounts.
Got a link for those guys? For the specs, I mean. What is the loading that he is proposing, what deflection does that produce, and what is the resonant frequency of such a system?
On the other hand, doubling your floor mass might move your studio form the 7th floor down to the 6th, unexpectedly...
You are already close to the load limit...
You might want to ask him if he recognizes the implications of these two equations:
T=2*pi*sqrt[m/k]
k=F/d
I'm guessing he won't have a clue what they are, and could consider them meaningless even if he did recognize them... Hint; they are related to springs and resonant frequencies...
If the spec worsens by doing this it would apparently be so slight as to be virtually insignificant.
That would be going the wrong way! Yet another misunderstanding. Increasing the mass of a floated floor will INCREASE the deflection on the springs, which LOWERS the resonant frequency, thus IMPROVING isolation. With two caveats: the springs are not overloaded, such that the deflection is outside the working range (in simple terms; the springs are not squashed flat), and 2) adding the extra mass does not cause structural failure! Once again, you hit your load limit on the slab under your studio.
In simple terms: If you didn't have a load limit for your floor, it would be dead easy to solve your problem: Float each room completely, and give it a high enough mas, with enough spring deflection, that resonance is way down in the single digits, and isolation is way up high. The problem is not that you need a magical combination of esoteric materials that somehow forms an esoteric sandwich that defy the physical laws of the universe: the problem is a lot simpler: your floor can't take the load needed to get the isolation you want. And there are no magical materials! Unicorn hair and pixie dust seems to be in short supply these days...
John Sayers also used to make certain claims that defied the accepted practices, insisting that experience trumps any theory that is commonly touted. You obviously left his site a while back,
Yup. About six months back, to be precise. And I'm not going to speak badly about him, if that's what you were expecting. I also think you misunderstood what he was saying. The point he was making with those claims was that, if you have enough experience, you don't need to do the math since you already know what will happen. Some people might think that in his case he never even did the math at all, ever... which isn't true in most cases; he even posts the calculators that he uses, some of which he developed himself, along with the equations. (He even wrote a book about acoustics, filled with all the usual equations). So he perfectly understands the math, and used it at one point... except later he no longer needed to do it, since he had done it so often that he knew what it would say. The same is true of most experienced studio designers: they can look at a product or a design, and give you a rough "guesstimate" of the performance without needing to do the math, and they won't be far wrong. And that's fine for typical situations! But when it gets to unusual things, beyond the norm, you still need math and theory. Once things are outside the realms of "common" and "normal" and "typical", then it's time to break out the equations and the calculator. You can't rely on experience for areas where you have none! On the other hand, your guy doesn't seem to accept math or equations or theory or science at all!
Even worse, he wont use math to check his own guesses.... He rejects your attempts to check his designs, and gets upset every time you try.... Red flag! Big one!
but would you say you and he diverged in opinion about various practices?
In essentials, no. He knows his stuff, as far as his experience goes, and I learned a lot from him that I later found to be correct when checked with math and science.
Would you dare to say that you had misgivings regarding some of John's methods (some which also refute common accepted "science")?
Seldom. And I don't agree that his studios are designed using principles that "refute science". I'd agree that he doesn't like theory too much, and does some strange things occasionally, but none that "refute science".
Has he ever been "wrong" about anything?
I imagine he probably has! So have I! So has everyone. We are all human, and sometimes make mistakes. Honest folks admit it, correct it, and carry on. Only a dishonest person would claim that he never makes mistakes, that all his efforts were perfect, flawless, with no failures, not even after building a thousand times....
any disappointed clients you know of? I understand if you'd rather not say,
I'd rather not say...
And to be very honest, I don't know of any studio designer who has a 100% perfect track record, with every single client being totally satisfied. I'm aware of some having higher success rates than others, but that's all I'll say. I'll also say that, personally, I would not trust anybody who said they had one thousand clients and every singe one of them was 100% perfectly satisfied, with no "disappointments".
but it is interesting how some of the old school guys seem to thumb their noses at the Gervais / Newell books that seems to be accepted as the industry's "Bibles"...
I don't have any beef against Rods' book (except maybe that he could go into more detail in places), but I'll happily jump on the bandwagon and thumb my nose at some of Newell's stuff! So will many other acousticians, both "old school" and "new school" (to coin a term....)... there just so much in "Recording Studio Design", for example, that makes no sense and flies in the face of science. Did it work? Sure! He got results. But was it all necessary? Nope. In many cases, the results he got by combining multiple layers of unusual material in exotic, undocumented ways, could have been obtained (or even exceeded) with more conventional materials in a far simpler (and proven) arrangement. A lot of his explanations are speculation, not science. "Layer 5 absorbed the low mids, and layer 7 cancelled the resonance, and layer 14 did something else, and all together we got 50 dB of isolation with only 23 layers..." Ok, I exaggerate, but that's the style of his book. You just have to take his word for it, most of the time... yet real theory and practice show that the multiple layers were not necessary, and the same results (or better) can (and frequently are) be obtained in far simpler ways. Don't get me started on Newell and his strange stuff... we had a discussion about that on the forum a while back... the general consensus was that we all agreed: Everest and Gervais and Toole and Cox and D'Antonio and Long and many others, all know their stuff, and use science, research, testing, theory, and careful documentation, with proven, repeatable, consistent, coherent, logical results. But Newell doesn't do that, for most of his book. The parts where he does have equations and theory and explanations are fine, for sure, and correct... but the parts where he describes how he actually built places, do not really use much of the theoretical stuff he spouts... it's just sort of "winging it": Not to mention that he only includes his successes in the book! As far as I recall, he doesn't discuses his failures...
So, no, I would not consider Newell's book to rise to the level of "Acoustic Bible Gospel Truth": maybe "cult ramblings" would be a kind way of putting it. Everest's MHoA is probably the one that most acousticians would call the "Acoustic Bible". Maybe Marshall Long's "Architectural Acoustics" too. And a coupe of other, less well known ones.
Anyway, getting back to the "old school" guys: my beef with them is that they know their "old school" stuff rather well, but acoustics is a young science, and is not static: it advances all the time, and just staying up to date is a challenge! There are new things coming out all the time, some of which can be incorporate into studio design, and some of which improve on the "old school" methods. There are now better ways of doing things, which had not been discovered 20 or 30 or 40 years ago when the "old school" guys were in their hay-day periods: They built rooms back then that worked, and sort of got "locked in" to that method... then didn't want to change and adapt as the science moved ahead, breaking new territory. And they still design studios the same way today! The studios still work, of course: just like they always did. So if you want a 70's or 80's style studio, then great! Use an old design from an old-school designer! Nothing wrong with that. But there are better methods today, better understanding of how acoustics works, how humans perceive sound, how that can be used to improve studio designs, better materials, better tools. So if you want an up-to-date studio design that performs better than the old school designs, then you have that option today.
For example: LEDE again. It was al the rage in the 70's and 80's, until the shortcomings were identified, and along came NER, RFZ, CID, and few others, which improve on, and extend the original LEDE concept. No modern designer would do a traditional LEDE room today! Yet a very few people still want true LEDE rooms, and one or two "old school" designers still do them, even though they suck, when compared to modern designs. There are far better design concepts today. You probably know that I'm a fan of RFZ myself, and pretty much all my designs are based on the RFZ concept... but I don't do standard RFZ rooms! I use the basic concept, but I do some things differently, because the science of acoustics has also moved on from when RFZ first came around. There are ways to improve on, and extend, traditional RFZ design, and that's what I do in my rooms. You can see the results in the rooms I have designed.
And maybe if another design concept comes along, with new research to show THAT it works better, and WHY it works better, then you'll see me leaving RFZ behind, and moving on to the new one. Because I don't plan to get bogged down in the past, like some of those "old schoolers" have done, who carry on building studios "the way I've always done it". Their studios might still work OK... as long as what you want is a design from 20 or 30 years ago, limited by what was known back then, and the materials that were available back then. But me? I prefer to stay up to date, and to things as well as they can be done today, based on current acoustic science and knowledge, not obsolete stuff from the last century. I want to give my clients the best that they can afford, the best available. Not a Model T ford, but rather a Bugatti or Lamborghini.. or perhaps a Tesla....
And here endeth my rant for today!
- Stuart -
I have plenty of diagrams and most of the usual information at hand to respond with incase you have questions, but let me just start with the basic proposed layout:
. Another excellent and much appreciated post. (I sent you a PM btw...)
They would not be in business very long, if they said that. Would you go to a restaurant that advertised how lousy their food was, after the installed XYZ cookers, and ABC food processing equipment?