Prefab studio and leafs...

Hi John, Steve... First off: great site, great work, great info. I've been reading a ton by know (including the important first posts :D ) and the more I read, the more I want to know. I want to have a good isolated practice room in my new house (in The Netherlands, that's Europe) where I can play at night with a band. So we'll have to bring some 120 dB back to a lot less. I own a prefab studio made by Esmono http://www.esmono.nl. It's basically a mass-air-mass construction. It's still too loud outside for my neighbours so I have to do more work. On the site they claim to stop some 45dB... but I cannot find any real testresults... If I would build this prefab studio inside a room in the big, big garage, would I be making a three leaf, two airgap construction? Or in other words: If I want extra insulation outside this studio: do I build a box in a box, or do I only put extra mass to the outside walls??? I know: you need more info. The room is big: it's like 9 meters x 14 meter and over 3 meters high. Space is no problem there. The floor is concrete. The walls are brick walls. Only one wall is in direct contact with the neighbours, the other three face the garden. I'm willing and able to do some work there! For me it's very important to keep the dB's down: we play a lot! I play drums with two bands and my wife is a pro-percussionist who wants to play her (LOUD) djembé's and stuff any time of the day (or night) Long question, maybe a short answer will do... And please forgive me for my English. I'm not a native speaker, so any stupid mistakes are not intended as such. Thanks for your help! Rob

Hi Rob, welcome; here's the basic concept, explained fairly basically - http://www.johnlsayers.com/phpBB2/download.php?id=3651 Your brick walls may be able to be rendered both sides for a higher mass outer leaf - then you would need at least 300mm or more insulated air gap and an inner mass leaf, such as double MDF or triple 15mm gypsum wallboard on a frame - for heavy percussion 24 hours a day, a HEAVY floated floor is mandatory - something like 150mm concrete floated on 50mm elastomer blocks, or on "jack up" spring units. Your inner walls should sit on top of this inner, floated floor, and a new ceiling frame (with also triple layer of 15mm gypsum) supported on those inner, floated walls. Ventilation will need to be included, there are threads here regarding that as well. This is a reachable goal, but won't be cheap - if you HIRE it done, you will still need to learn as much here as possible or your contractor will very likely mess it up BADLY. The DIY approach takes longer, but will cost quite a bit less. If you can post either pictures or a sketch of your space, it would probably help; also, more info on your surrounding neighborhood. Re-reading the "don't even think about" announcement will give you an idea of each point needing to be covered. Also, don't worry about your English; it sure beats the crap outa my Dutch or Frisian... Steve

Thanks Steve ("Dankjewel!") for your fast reply. I'll try to Sketch Up some pics of the room and put up more info about the materials and such this weekend... Rob

Hey Erwt, Steve's concept of a floating floor studio is described in the most famous studio building diary around: Paul Woodlocks diary at the www.studiotips.com forum :D

Thanks Bert... While I do understand a lot (but totally not all yet, by far) about building floating floors and building a box in a box, I'm still bugged by this question: Can I use a prefab studio (it's a good size: 4.00 x 3.70 meter) inside a box in a box construction, when I keep enough airspace, or would I be making a three leaf, two airspace kind of thing, which might HURT me badly? So: KEEP the studio and do EXTRA insulation, or SELL the thing and start building a small Pentagon in my home? The prefab studio is two layers of metal with insulation inside. It's accoustically dead inside (which won't hurt us, being drummers) but still a tad too loud on the outside. Mostly (ofcourse) low freq's leaking. More info on the site of the Dutch vendor: http://www.esmono.nl Cheers, Rob

Not sure of exact values, but even placed in the center of your large room the "3-leaf" effect wouldn't be entirely gone; best way to see if this works would be (since you already HAVE this box) set it up in the center of your larger space, close all the doors and windows, put someone inside beating the crap out of your loudest toys, and measure/listen outside with the outer doors closed and open; if your lowest frequency stuff is quieter outside with the outer door SHUT, you win: Be aware that this may NOT get you better iso at lower frequencies, so this is a TEST; it may or may not work. Frankly, I don't know which way will be quieter (although the extra leaf WILL help at mids and highs) ... Steve

A prefab studio could be a valuable thing, but when I look at the specs I think it's all a bit light weight. But my mate Steve will kick my ass as soon as I begin to BS :D It's a load of trouble, but when you want to have it done properly, you should go to the long road. Heavy floating floor, walls on it and a decent roof, all i the same weight class. A "pens met werk", forgive me, but cheap solutions work out cheap often :P Could you give a very detailed scetch of your situation? With distances to neighbours, are the houses attatched, constructons etc? Groeten, Bert

Okay, many thanks for the input. I'm back to the drawing board now. No prefab studio, but the REAL thing! It's no problem to sell the thing, I had it second-hand myself. There won't be much loss of euro's there. I'll go out and measure EVERYTHING, draw a pic of the situation, including the materials, neighbouring places etc. Wow! The ´many steps of insulation´ really are true, aren´t they... Feels like I'm back to: "Darn, there's a lot to learn!" Cheers! Rob

Rob, You should find out if and how your house is constructional connected to the neighbours house. To get insight in flanking paths of the sound (falnkerende geluidsoverdracht).

http://irc.nrc-cnrc.gc.ca/fulltext/rr103/rr103.pdf Warning; this doc is about 288 pages; choose "save to disk" or be prepared to wait a long time... Steve

Erwt wrote:

Wow! The ´many steps of insulation´ really are true, aren´t they... Feels like I'm back to: "Darn, there's a lot to learn!"

Looks like Rob is at #11 on Stages of Soundproofing Enlightenment! ;)

:P And counting... Okay, thanks so far for the imput. Things changed. Today I bought another house. From another musician who makes me want to go to the thread "How to finish a poorly begun job", because he built himself a terrible studio... I'll measure everything soon and come back with my first ideas about soundproofing this new place... I'm a happy little Rob now... with the house... (I'm happy little all the time: www.hl3.nl)

Erwt wrote:

:P And counting...

Progress is good! :-)

Today I bought another house.

Congratulations! That's exciting. :-)

. . . From another musician who makes me want to go to the thread "How to finish a poorly begun job", because he built himself a terrible studio...

Oh wow -- that will surely be a challenge. :shock:

I'll measure everything soon and come back with my first ideas about soundproofing this new place...

Yeah, can't wait to see the photos and the cutaway views of this thing. :)

I guess you could use pics of his "audiotorium" as a lesson in how not to sounproof a place... He used a lot - and I mean a lot - of wood and insulation, but really didn't care about getting it airtight (he left the ceiling totally empty, because of accoustics). The floating floor doesn't float. It's just sitting there on the floor... It's fun... I only get the key in August, but I'll have a chance to take pics before that... The good thing is that I have more time to think about my plans... And one thing I've learned at this forum is that good and long thinking and rethinking is a very good thing, which in the end will save a lot of time and effort... I'm looking forward for this project! Cheers, Rob

Steve, Reading through this thread and having read many, many, many pages about soundproofing one question keeps bugging me... When we are talking about Sound Isolation and building a room in a room, I do understand the two leave-construction when separating two inner rooms (i.e. the control room to live room walls etc.)... BUT: Whenever you build a construction facing an "outside" wall, building a mass-air-mass construction will consequently ALWAYS give you a triple-leaf-system.. or not? I've been reading Paul Woodlock's interesting (and VERY LONG) diary about this. He opted for a very heavy single-mass construction, leaving an air gap and using the outside walls of his garage as the second leaf. I'll have to soundproof a garage as well. It will become a one room practice place... With four walls, a ceiling and a floor to consider.... I don't want to mess up by making it a three leaf construction with complaining neighbours. So.... do I build an mass-air-mass construction inside the garage or is it preferable to construct a very heavy one mass wall on a floating slab... then have an airspace to the outside wall and maybe put some extra mass to those outside walls.... ???? Very curious, as it is not only a practical question that might help me out in THIS case, but also might change existing theories a tat? Cheers, Rob

This one, definitely - preferable to construct a very heavy one mass wall on a floating slab... then have an airspace to the outside wall and maybe put some extra mass to those outside walls Even a single thickness of outer siding on a garage, when followed by an insulated, WIDE air gap and a heavier inner mass, is far superior to ANY triple or quadruple leaf construction for low frequency isolation - and since this is the most difficult to isolate, the LF should be the deciding factor in construction... Steve

Erwt wrote:

Okay, many thanks for the input. I'm back to the drawing board now. No prefab studio, but the REAL thing! It's no problem to sell the thing, I had it second-hand myself. There won't be much loss of euro's there.

I am moving to a new house which has a very large garage. I am considering buying an esmono pre-fab studio the same size as yours. I do not need huge sound isolation as my work is mainly acoustic. What I really want to know is what you think of the acoustics inside? Does it need much additional treatment to get a good sound? Cheers Ian