Small bedroom turned into a Studio (construction phase)...

Here goes the Design topic: viewtopic.php?f=1&t=18618 And here are some pics from the progress "on-site ": :)

What's the purpose of that resonant box on the floor, in the first few photos? I can't seem to figure out what that is supposed to do... Also, the HVAC silencer box looks well built and seems to be a good size, but it is not lined correctly. That white fluffy stuff is not what you need. You should be using proper duct liner. That needs to be fixed before you progress too far. - Stuart -

Hi Stuart and thanks a lot for the advises ! 1) The resonant box is actually a floating floor. If you check the design topic (in the beginning of the first post there is a link) you will see a cross section with the layers. I have combined Mr.Sayers construction with some additional layers (deadsheet and gypsum board) as in Newell's book. A small recording booth will be on top of it, "room-in-a-room" style, no connection to other walls and ceiling. 2) The "fluffy" thingie is actually the backside of BITUVER FONAS 31 bitumen deadsheet... thin enough and I though it might do the job. I can change it still, however :) Thanks again for taking time to check my modest progress :) Cheers, Yavor

And an update from last night. Booth stud construction ready. Please note all studs are at least 20mm. from wall/ceiling. Actually in corners the distance is 40-45mm. The room is pretty far away from a perfect rectangular shape .... :mrgreen:

1) The resonant box is actually a floating floor.

You probably should read this thread before you go any further with your floating floor! : viewtopic.php?f=2&t=8173 What is the original floor in the room made of? And what is under that original floor? How is it supported from below?

2) The "fluffy" thingie is actually the backside of BITUVER FONAS 31 bitumen deadsheet... thin enough and I though it might do the job.

According to the data sheet for that product ( http://bituver.it/en/wp-content/uploads ... 1-rev4.pdf ), it is designed for reducing impact noise, not absorbing resonance in HVAC ducting. There is no impact noise going on inside an HVAC silencer. Also, those fine fibers will slowly erode from the air flow over time, and they will end up all over your room, and inside your equipment and instruments. What you need is proper duct liner, which is suitable THICK (not thin), and has a specially bonded surface to prevent the fibers from coming loose: http://www.armacell.com/www/armacell/AC ... .12.09.pdf http://www.industrialnoisecontrol.com/m ... -liner.htm http://www2.owenscorning.com/around/sou ... BERGLA.PDF http://www.hamiltongv.com/DataSheets/AeroflexPlus.pdf http://www.specjm.com/files/pdf/AHS-370.pdf

I can change it still, however

That would be a really good idea! :) - Stuart -

Hi Stuart, Big thanks again ! 1. Re: floor. Yep, i have read the thread. Still decided to make a FF, hope i did not do a bad thing... You may check in detail if you want the cross section in the design topic, basically bellow is another floating floor with 60mm concrete screed/ 30mm hard glasswool/ 240 (or so) mm concrete slab and another 400mm light glasswool. The construction is rigid enough to hold the new load if that is one of you concerns. The room is on the 3rd floor of a house, upper floor is mine as well, the one bellow has a different owner. 2) Re: flufy thingie: I am stupid, fullstop. Will be changed with some 20mm glaswool slabs I have. Actually i'll use an Ecophon ceiling plate with glass tissue on one side to avoid particles spreading... Thanks a million again! Cheers, Yavor

The construction is rigid enough to hold the new load if that is one of you concerns.

My concern is that, with a concrete slab under you, you don't need to float your floor at all! A simple "drum riser" type of floor would be all you need if you plan to have something in there that vibrates the floor or creates impact noise (bass cab, percussion, drums, etc.), or if that is just a vocal booth, then you don't even need that: just simple laminate flooring on a good underlay is all you need for vocals. What you have done there is to create a resonant box with two cavities that is NOT a floating floor, since it does not have enough mass to be one, and is not decoupled on resilient supports. It is some type of 3-leaf system, so it will not be good at isolating low frequencies, and you have lost 28 cm of ceiling height in addition (since the floor is 28 cm thick). So you have reduced the volume inside your booth, and made the ceiling much lower than it needs to be, thus harming the acoustics of the room. But what concerns me even more is that you see to be building your walls on top of that "floor"! :shock: That's plain dangerous. There is NO structural support for those walls. You cannot do that safely. You cannot build walls on insulation batts! That needs to be fixed. Walls MUST be attached to the floor, either directly or with proper resilient supports that are specifically designed for the purpose. What you are doing is dangerous, and should be taken down and re-built correctly, before someone gets hurt.

Will be changed with some 20mm glaswool slabs I have. Actually i'll use an Ecophon ceiling plate with glass tissue on one side to avoid particles spreading...

I would not recommend that. Duct liner is the only type of material you should be using: that's what it is designed for: to be used inside ducts that supply the air that goes into your lungs. I would not use anything else, since lungs are rather valuable! I would not risk unknown products with unknown properties when dealing with the air that I breath.... Healthy lungs are worth a lot more than the cost of a few square meters of duct liner... :) - Stuart -

Thanks Stuart, Seems like I have a lot of things to reconsider... The only good point is I am in the beginning, and changes still can be made... with your guidance. All's well when it ends well :) Thank you !

OK, last input from my side. All points mentioned by Stuart taken in consideration and construction changed. Thank you for the time and the advises ! I would allow myself to disagree on one point though. Such a (relatively) light construction might be and is completely safe to build on a heavy mineral wool base. I was using a stone wool slab with a density of 160kg./m3. Generally speaking, dedicated floating floor slabs (glass- or stonewool) are able to withstand a load of 500 up to 1.000kg./m2, without any deformation. My construction, as built till now has a combined mass of approximately 300kg./m2. The slab that I used will not deform by a load on top less than 1.000kg/m2 (10 kPA). I do not want to get into an argument, just giving a side opinion. Best regards to all!

Hi Guys :) Nope, I did not give up... no way... And here's the current status. Call me stubborn and stupid if you want. However, I have decided to stick to the initial design. Some pictures of the development in November and December, without comments: Only components still missing are the bass-traps (both in booth and room, after the last panorama pic was taken I installed all rest absorbers in booth). Will be finished in a couple of days... My observations: 1) The construction is rock-solid. Nobody was, or will be hurt, ever. Believe me. I have been in the mineral wool business for some years and I was sure it would work out the way it did. Rigid floor slabs are supposed to bear weight with no deformation. And they do. If you know how to handle them. 2) Insulation: I am happy with the result. I have stopped troubling whether the system is 2-3 or 4 layers or whether the floor is a resonant box. Bottomline - in the control room the SPL is not exceeding 60 dBA with 110-115 dBA in the booth. That measured in front of the double glass window (normally and logically the weakest point of the whole system). Upstairs and downstairs it is DEAD silence. Yep. No bass frequencies, no whatever frequencies passing. As simple as that :) Check that link out and see for yourself: http://youtu.be/cM5NZCCHIzs 3) With most of the absorbers already in place (used dedicated 40mm. ACOUSTICHOC stone wool panels with special fixation profiles produced by EUROCOUSTIC), still no bass traps installed, I will do the REW measurements in a couple of days. I can tell you the bass traps absence is pretty audible, however. All in all, the control room feels pretty OK... with a pair of new ADAM A7X (just arrived) I feel I would not dare to ask for more. Bottomline: it was a challenge, given the small dimensions and all. I am happy, though exhausted and tired as a dog. Everything passed thru my two hands... I would like also to suggest there is always more than one road leading from point A to point B, and sometimes both roads may be the right ones :) Thanks from all of my heart for all the concern and advises ! Merry Christmas to everybody, my sincere wishes for a very Happy, healthy and successful New Year. Be strong and be loved ! Cheers, Yavor