John Sayers' Recording Studio Design Forum

Hi!

Sorry about my tiny question but I dont want to waste money and havent find the answer by searching.

I have a room in officebuilding and it has gypsum walls with rockwool inside it (single leaf wall). I want to make it little more soundproof. If I install rockwool on top of the existing wall and make new wall against it with airspace and rockwool (like doubleleaf construction method) is it a really doubleleaf wall or do I have to take the gypsum out of the existing wall first, then build the new wall against it. I dont want triple leaf walls.

I attached picture below about it.

Thanks for advance and sorry my bad english!

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if it works, someone else did it!

What you show in the graphic looks to be a 'triple-leaf' design.

So it doenst isolate more, even if it has more mass than ordinary double-leaf? You think it is better to take the gypsum off from the existing wall?

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if it works, someone else did it!

Actually, that's a two-leaf wall, not a single leaf. Yes, the two leaves are coupled through the studs, but they still act as two leaves, not one.

plan "B" is right: take the drywall off the existing 2-leaf wall, making it into a single leaf, then build your new single-leaf wall nest to it.

Like RJ said: what you show is a 3-leaf wall.

By adding the new third-leaf in front of it, you actually re-tune the MSM resonance of the wall. It will now have two resonant frequencies, F+ and F-, instead of just one (F0), and they will both be higher than what F0 would have been. Depending on how the existing wall is built, and what it's current MSM characteristics are, that might or might not be a problem, but most likely it will be a problem.

The big question here is: how much isolation do you need, and for what purpose? Isolating enough for an acoustic guitar for a house out in the country is very different from isolating enough for a heavy-metal rock band next to a day-care center for sleeping babies!

- Stuart -

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I want this studio to amaze people. "That'll do" doesn't amaze people.

Huge thanks for your reply!

Plan B actually suits us better, we cannot afford to lose any space or money for nothing . This sounds very bad I know, but we are trying to isolate our next door neighbour, a band with death metal DB. So your second supposition happens to be quite right. Good advices are welcome

We start by taking the gypsum off and build the second leaf with 50mm rockwool. Whats the minimum airspace suggested for 50mm rockwool and thickness for the gypsum approximately in this situation? I know it is frustrating to guide if dont know how much must the isolation exactly be but lets just say we want to do this as good as it is possible. Budjet is somewhere around 1500€ (1872.64USD) so we know we cant afford making dead silent neighborn by constructing or any other method .

Thanks for advance!

edit: Sorry, I forgot to mention that the deadly band that we are trying to isolate isnt behind our wall, there is empty room between us. Purpose of our space is mixing and producing music.

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if it works, someone else did it!

I have a room in officebuilding and it has gypsum walls with rockwool inside it (single leaf wall). I want to make it little more soundproof. If I install rockwool on top of the existing wall and make new wall against it with airspace and rockwool (like doubleleaf construction method) is it a really doubleleaf wall or do I have to take the gypsum out of the existing wall first, then build the new wall against it. I dont want triple leaf walls.

Im having hard time with the floor issue! The floor is concrete and band next door is playing with the same concrete floor as we do so is it waste of money to try to make our floor floating? If it isnt can someone really tell how to do it right for our cr room? Our CR is dimensions are 4.5m x 3m height is 3.12m.

We are trying to avoid the floating floor becouse of the cost of it but if theres no option to make well isolated CR without it we will manage money for that. Ofcourse all other options are more than welcome!! The first leaf is now sealed tight with akuseal and it is waiting for rockwool to be installed. The next important thing is the floor. Do we have option to make the "new" leaf from the concrete floor to the concrete ceiling or does the new leaf have to be or is it better to be on top of the floating floor if it is made. I have seen many posts that say it is worth nothing to make this so called floating floor as seen in "youtube" and so on... Our original plan was to make it float by using neoprene rubber (we have it in stock... hardness 65) and 100mm thick rockwool between the 600mm width joists that I guess isnt the way to do it?

Thank you!

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if it works, someone else did it!

How bad is the problem? That would be the first issue to look at. Is the floor really a flanking path, or not? For example, when the rock-band next door is in one of their sessions, can you feel, vibrations in the slab when you touch it gently with your fingertips? Another method: get a stethoscope, and listen to the slab with it: can you hear anything in the slab? IF you come up negative on those, then the slab is not the problem: the walls, windows, doors, ceiling, HVAC and electrical systems are the problem.

But if you do clearly have a problem with the slab, then this should help you to decide if you need to float your floor or not:
viewtopic.php?f=2&t=8173

And if you want technical information on how to do it right, and what to expect as a result, then this goes into greater depth:
http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir802.pdf


These threads might also be helpful:
viewtopic.php?f=2&t=8134
viewtopic.php?t=8135

But one thing is for sure: I wouldn't trust the YouTube path, unless the author of the video is a recognized acoustician or studio designer, demonstrating how a professional studio was done, and proving the results with suitable tests... It's just so easy for any ignorant idiot with a camera and a half-baked idea to make a video and claim magical results. For example, take a look on YouTube to see how many "home studios" you find with egg crates on the walls and carpet in the ceiling, where the author thinks he has done something wonderful...


- Stuart -

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I want this studio to amaze people. "That'll do" doesn't amaze people.

Thank you Stuart! I like your style telling the things just how they are in this forum...cold truth with warm touch .

We think that our engineer talents are not even close to make the floating floor work. So we put our effort and money to walls, doors and windows. Maybe we make floor on top of 50mm rockwool inside the innerleaf so it seems like it floats . Makes the floor warm if nothing else...

Again, huge thanks to you!

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if it works, someone else did it!

Have anyone done slatestone soffit panels? Could it work? Im thinking to install slate to drywall (gypsum). Does it help to get the panels thick and heavy in right way?

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if it works, someone else did it!

Slate would work fine. You want the panel as massive (heavy), solid and rigid as possible, so if you can figure out how to cut the slate to fit the speaker, and how to support the weight, that would work fine.

Oh yes! Thick and heavy is good. Tom Hidley even used concrete for some of his, apparently.

Slate would probably look pretty cool, too.

- Stuart -

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I want this studio to amaze people. "That'll do" doesn't amaze people.

Thanks Stuart!

Does it matter if the finish of the panel isnt as smooth as plywood or mdf would be?? How about the symmetry of the panels? Its impossible to make two identical slates . I´ve already started to do it so please give me some good news

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if it works, someone else did it!

OK, good news! The surface does not have to be perfectly flat and smooth. The frequencies that cause all the problems are lows, not highs, so minor imperfections won't have any effect.

The not so good news: symmetry is still important, within reason. The left and right panels need to be roughly the same size and shape, and angled the same. Of course, you don't have to get the sizes precise, down to fractions of a millimeter, but within a cm or so would be good.

How different are they?

As we say around here: "Photos, or it didn't happen!"

- Stuart -

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I want this studio to amaze people. "That'll do" doesn't amaze people.

Photos will come as soon as we get camera somewhere . I had to change the plans about the slate. It is just too heavy to install without very heavy structure. So we used 16mm gypsum panel with concrete finish (about 2-5mm using fast concrete).

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if it works, someone else did it!

Our room length is 395cm, width 255cm and height 235cm. Im trying to solve sidewall slat heights and slots. I´ve used Bob Gold room mode calc. but dont understand it so good. Am I trying to absorb as good as possible this -> Room Modes dominate: 43hz to 152hz and more accurate those that have more % shown in calculation? Im going to make two slot walls (70cm width, deepest 20cm, lowes 5cm) to both sides in 12 degree as seen in Johns example room. I was planning to use same slot measurements as in Johns example but in his example the room is littlebit shorter.

Do I have to make different sizes of slats or can I just use same size slat with variable slots? Whats the difference? And how many exact hz is it reasonable to try to absorb with one wall? Is it smart to use two walls to absorb same hz and make two other absorb different or does it loose its effectiveness when doing so? And how to make wider Q to it so it would absorb nearby hz also?

(sorry, our slotwall dimensions arent exactly as in Johns example but the principle is the same I think)

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if it works, someone else did it!