double leaf effect cost more than triple in most situations.

3 walls are build-up to test possible differences between 3 different RC models. That bad curve is the same wall based on wooden studs without any RC. What you see are structural resonances and flanking.

Eric, I'm just curious here: On that graph that you posted from NRCC-44692, the resonance dip seems to drop from about 120 Hz. on the basic wall to about 60 Hz. with all three types of RC. Is that drop due to the decoupling provided by the RC, or to the deeper air gap, or to something else? - Stuart -

Ted White wrote:

I don't believe inserting a third leaf makes LF worse than before

And that comment from a man that proudly displays a soundproofingcompany.com link in his sig. Well I admit I have no idea to what the suggestion that Mr. White is correct about because whatever his point was...keeps moving :) My opinion has not changed about the initial question, while the initial question has morphed into something entirely different. I thought it was a general acceptance that a three leaf is just like the existence of spiders, your never more than 3 feet away from one at any given time. So you live with it, try to understand it better, but you still live with it. I have my own "proof" that a three leaf is not recommended and can support that the LF will in fact be worse as will the TL and the STC and the FSTC and the IIC. In a nutshell, he may be selling it, but I ain't buying it :)

Soundman2020 wrote:

And if you want the theory behind it, with abundant examples and numerous real laboratory tests, then the best I can recommend is the 1973 Wyle report: http://www.box.net/shared/jcaoavdc8g It might be old, but it is still very, very valid. And very interesting reading. - Stuart -

Stuart, I never reviewed that document before....... One thing I found very interesting was that one of their assesments of 3 leaf construction noted that it might be a worthwhile consideration for construction when seeking to take the minimum TL value of the assembly to greater than 20dB...... something they are not seeing as a reasonable consideration with 2 leaf frames......... Rod

This is an interesting thread and I thank all the participants - unfortunately I've just been through a C:/ drive crash and have been busily rebuilding my computer. Here's a pic to consider - I was amazed that no one picked it up at the time. taken from and this from this thread viewtopic.php?f=10&t=9156

John, what was the story behind that partition? That was a very long thread you linked. Maybe you could give a two sentence brief for us.

John Sayers wrote:

Here's a pic to consider - I was amazed that no one picked it up at the time. <pic removed, to be seen higher up> taken from

Not preserved: STONEHILL-SD-110108 SHEET2 (A3).pdf

and this

Not preserved: STONEHILL-SD-110108 SHEET1 (A3).pdf

from this thread viewtopic.php?f=10&t=9156

Lou, You have all reasons to be proud on your work and studio. But from a building physics point of view, I'm really sorry, that's a stupid design showing that these "The Studio People" don't have related insight and background. I once had a similar discussion with Galaxy and Eastlake Audio at the Catholic University of Leuven. That's a whole story, but the result was that within an hour Galaxy understood that a big name in the studio world and knowing physics are not the same thing. Just some additional references I looked up: http://www.studiopeople.com/clients_st24.asp http://www.studiopeople.com/index.asp http://loustonehill.com/studio4_home.html

Here's a pic to consider - I was amazed that no one picked it up at the time.

I'm looking at that pic, and scratching my head, and thinking: "Isn't that a SEVEN LEAF wall"??? :shock: Or am I misunderstanding the diagram? - Stuart -

Soundman2020 wrote:

Here's a pic to consider - I was amazed that no one picked it up at the time.

I'm looking at that pic, and scratching my head, and thinking: "Isn't that a SEVEN LEAF wall"??? :shock:

Such a picture makes me angry and stunned. It doesn't matter how many leafs this are. This is drafted by people without related knowledge. Such people sell themselves as related experts.

I'm trying to get my head around this. Eric, wouldn't a 7-leaf wall have all kinds of internal resonance issues? Wouldn't it also have a pretty high over-all resonant frequency, for the entire "MSMSMSMSMSM" system? Some leaves are two layers of drywall, some are one, some have large air gaps, some small, some with damping insulation in the air gaps, some not... It must be extremely complex to even calculate the acoustic properties of such a wall, surely? I just don't get it. It flies in the face of everything that I've learned about acoustics and isolation (which, admittedly, isn't all that much). Apart from being really expensive and hard to build, I just don't see the acoustic logic behind the design. - Stuart -

Stuart, I doubt (99 % sure) that anyone can calculate/simulate that. One can calculate simple systems at straight incidence, but room acoustics adds a lot of unknowns and uncertainties. (angle of incidence, bending waves in the panels, and so on). There are animations on the web but I can't find them now. You have as many resonance frequencies as you have cavities (exacter expressed: degrees of freedom), but this are not the individual resonances per adjacent pair of leafs, but the interactions between all these masses. At studiotips we have searched at a certain moment to find enough measured data of triple leaf systems, without much success. One can calculate this in a stylized manner which is based on the mechanical response of mdof systems. This works rather perfectly if one wants to calculate silencers. Room acoustics however adds a lot of uncertainties. If you want to know how a double leaf system works check this animation and play with the parameters and frequency. http://www.walter-fendt.de/ph14e/resonance.htm I also find discussing wrong principles in the context of their purpose in a studio forum a bit a loss of time. (I spent some time trying to find clear animations, but without success for now).

Soundman2020 wrote:

I'm looking at that pic, and scratching my head, and thinking: "Isn't that a SEVEN LEAF wall"???

To add my confusion, that wall is flanked on the north (in the drawing) by 2 doors into the kitchen/soundlock. :roll: A slight mismatch in TL. Andre

Thanks Eric. That's what I figured. And thanks for the link to the animation! Makes it easier to understand, visually, what is going on acoustically. And gives you an idea of just how complex a "simple" MSM wall actually is. Much appreciated. - Stuart -

This is absurd to say the least.......... the amount of money that this man threw away for his studio construction is beyond belief......... To say he was robbed by this company would be an undersatement......... Just goes to show you how easy it is for a bunch of people to present themselve as knowledgable and have a gullible polulation believe them......... a shame

To add my confusion, that wall is flanked on the north (in the drawing) by 2 doors into the kitchen/soundlock.

You know, the more I look at those drawings, the more things I see that confuse me. Like this section around the toilet and vocal booth, for example:

To me, those walls appear to not be decoupled: The two sets of studs are back to back, and coupled through the drywall, aren't they? There also seems to be a direct flanking path directly from the outer leaf through to the CR inner leaf, along the toilet wall. And I don't get the purpose of that thing that appears to be a single sheet of drywall right next to the sink, extending unsupported from the CR wall to the outer leaf. Or that the aim points for the front and rear speakers, that appear to be different. Or several other things. Very curious.

And the worst design mistake... Carpet in the bathroom.

hahahahahaha

can you record in that bathroom? In my opinion move the bathroom and make the vocal room bigger. and decouple those walls dividing the vocal room and control.

Andy, you might want to follow those links back to the original thread: The room is already built, finished, and in use. I doubt that Lou will change a thing today. - Stuart -

It looks like a lot of fun but most of what you guys are doing is making fun of a man who made some mistakes and the cost was to him, not any of you. I think, for me, one of the greatest gifts that Lou gave was that he continued with this effort, mistakes, cost and all, kept the documentation and the community involvement to a nice level. That is rare. Many others would have simply quit with no apparent reason. And to add insult to the injury that you guys are pouring salt in....where exactly were you when this was going on as John has pointed out? If there is any disgrace, it is that.

Eric_Desart wrote:

John Sayers wrote:

Here's a pic to consider - I was amazed that no one picked it up at the time.

Lou, You have all reasons to be proud on your work and studio. But from a building physics point of view, I'm really sorry, that's a stupid design showing that these "The Studio People" don't have related insight and background.

xSpace, Knowing Lou is a member, and reading some of his enthusiastic and professional, super organized work, seeing the interior of his studio I know he can be proud, and my anger (not fun) directs itself to a company selling themselves as experts misusing the rightful trust of potential customers. At the time I certainly didn't see these documents, because I would have reacted without any doubt. Just one glance shows me this typical lack of related knowledge hidden behind the magic/mystics of acoustics, therefore I'm also not looking further for details. This lack of knowledge possibly/likely means that there are still other not visible errors against physical principles.

but most of what you guys are doing is making fun of a man who made some mistakes and the cost was to him, not any of you.

Brien, I really don't see it that way. I don't think anyone is making fun of Lou, or his excellent thread, or his incredible dedication, nor his finished, successful studio. I hope I didn't come across as "making fun of him", because that certainly isn't my intention, and I don't think it was anyone else's intention either. I, for one, greatly, greatly admire Lou and what he accomplished. That's one of the drawbacks of forums like this, I guess: you can make a serious comment in good faith, and have it interpreted by someone else as something totally different from what you actually said, or intended to say. Not being able to see expressions and hear the tone of people's voices is always an issue on forums, especially as here where there are many people from all around the world whose first language is not English, and who make huge efforts to do their best in a foreign language, but can easily be misunderstood by others, due to a slight misuse of grammar or punctuation, or a missed subtlety. So I don't see this thread as being "making fun" of anyone. Rather, I see it as an opportunity to learn: As Eric said, to learn that not all big-name "studio builders" (or even small-name ones) actually know what they are doing. Just because a company has a long list of clients does not imply that they are competent. I'll bet you know that yourself form the building industry! And also to learn that basic errors can slip by even here, where a whole bunch of real experts post regularly, but a design happened to get posted when none of them was looking. And also to learn that it is very, very important to understand the principles of acoustics as well as one possibly can, to hopefully avoid this kind of situation. So, Lou, if you are following this thread and took offense at anything I said, then I apologize: it wasn't my intention at all. I'm just really, honestly curious as to how your studio actually works (acoustically), and I know it does work because you have made many successful recordings in there, and have stated numerous times how happy you are with it. I'm not questioning that it is a successful build at all! I'm curious as to WHY it works so well, despite those issues that Eric, Rod, John, Andre and others have pointed out. That's the purpose of my comments: just trying to understand it, in my endless quest to get a handle on sound and acoustics. - Stuart -

xspace, my comments were not directed at Lou in the least - but rather at the people he paid good mony to - in good faith. People who present themselves as "professionals" in the field of acoustics - who don't seem to even have a grasp of the basics....... This (to me) is a shame (to say the least) and these sorts of firms get me rather outraged. The fact that the design works and suits Lou's needs is (in my opinion) secondary to the fact that he could have acheived the same exact results (from an isolation point of view) for a ton of less money........ I (for one) try as hard as I can to catch what I can - as I am sure the rest of the folks do - but no one is going to catch everything....... I do not often even visit the design side of this forum - but contribute what I can to the construction side - although (in all honesty) I can't remember ever seeing this particular build. Please do not interpret my outrage as being directed at anyone (or anything) other than what it really is directed at - which certainly does not include Lou. Rod

Soundman2020 wrote:

I'm just really, honestly curious as to how your studio actually works (acoustically), and I know it does work because you have made many successful recordings in there, and have stated numerous times how happy you are with it. I'm not questioning that it is a successful build at all! I'm curious as to WHY it works so well, despite those issues that Eric, Rod, John, Andre and others have pointed out. That's the purpose of my comments: just trying to understand it, in my endless quest to get a handle on sound and acoustics. - Stuart -

Stuart, you might well never find the answer to that pparticular question.......... sometimes things work in spite of themselves.......... Sometimes you can overcome a bad design just through the amount of mass you have in place - perhaps this is one of those cases....... Regardless - why it works isn't (in my mind) worth figuring out - rather I ask why anyone in their right mind would design along these lines (anyone with real knowledge that is). It just doesn't make sense. Rod

Holy shit - Er uhm?...............................................Sort of thanks guys I guess? To the two 'newbies' that very clearly haven't read my entire thread or looked carefully at the 1500 plus pics, the restroom is laminate flooring, I picked up on that when the drawings came through. Why have a self-contained toilet? Sorry dudes, but I wont even dignify that with a reply. And, everything was built inside the 'outer leaf' so there is no flanking path to the outside world. Studio sounds great, isolation awesome, acoustics unreal, everyone over the moon, gotta' go 'cos I'm too busy producing MUSIC Please take up any other design issues with the people involved, (I'm hacked off with being the middle man here - let me know how you all get on!) but bear in mind Jeff did change a shedload as he went along, so in all honesty those drawings do not now accurately reflect what was actually built. When any of you want to come and take a look/listen at what's here, please do get in touch, Eliot at Songcave Studios in the Australian Blue Mountains did, and he was knocked out! Better still, why not call Mutt Lange? He was Jeff's client before me! Fondest regards, Lou. :lol: P.S. Thanks Brien :wink: P.P.S. Thanks Eric (Sorry we missed you in Brugge last Christmas!) P.P.P.S. Rod - I Hear where you're coming from, and you have seen my thread because you kindly commented on it twice I believe. Once re: my original wiring plans, and to say shame about my 'hat channel' instead of RC. :wink:

Hi guys. I don't know if this is the best place to put this, but it seems more relevant here. The more I read, the more I search, and the more I search, the more confused I get. Rod wrote this:

sometimes things work in spite of themselves......... Sometimes you can overcome a bad design just through the amount of mass you have in place - perhaps this is one of those cases.......

Perhaps this is too, but I'm really confused WHY a PRO ACOUSTICS company, would use a SIX LEAF system in the first place???????? Is there a point WHERE 2 Leaf systems with the same MASS, will NOT perform as well as a 6 leaf system? http://www.studioschemes.co.uk/for_case_study_2

Regardless - why it works isn't (in my mind) worth figuring out - rather I ask why anyone in their right mind would design along these lines (anyone with real knowledge that is). It just doesn't make sense.

Rod, in this case, it IS worth it to me figuring out WHY IT WORKS if indeed it does better than a 2 leaf? Otherwise, I've been missing something for YEARS. Here is a statement on the same page as these pictures.

Isolation Specification The isolation specification is based upon both the isolation from the building and isolation between rooms. Low frequency cross-talk (isolation) between adjacent studios. The specification of acoustic requirements includes an agreed sound isolation between each of the studios. The design of the wall must exceed this specification, as it needs to perform in ‘real world’ site conditions where it is penetrated by ductwork, fire alarm and electrical cables etc. The detailing of these penetrations is critical to the performance of the wall.

I don't understand what the penetrations have to do with the quantity of leafs? :? Rod wrote this as well.

Just goes to show you how easy it is for a bunch of people to present themselve as knowledgable and have a gullible polulation believe them......... a shame

Would this apply here, and if not, PLEASE...can someone tell me what I'm missing, cause I'm missing something. I mean, I see these sort of things in Mr. Newells book as well. What is going on? :? :? :?