CONSTRUCTION HELP, WILL THIS WORK?

So it's better to do it as depicted or could I just add angled walls inside a squared isolated room? You can go either way; for compactness' sake, making your inner mass as angled walls saves money and space. The other way would be to make a squared mass-air-mass room, make that part BETTER than it needs to be, and THEN do angled walls inside THAT. Problems here are than now it will act as a 3-leaf, so your outer two masses need to be more massive by about half in order to keep the same amount of isolation. The UP side of that idea is that you can, with some calculation, use the innermost angled walls partially as panel-type bass traps which would lessen the need for interior trapping somewhat. However, doing it that way is a LOT more expensive, and the calculations aren't real easy. Probably your best bet would be to use the sketch you just posted, only move that single layer of wallboard over and add it to the OTHER two on the INSIDE of your framework. This will increase the mass of the inner leaf AND widen the air gap, two GOOD reasons for doing so. Well the first sketch was wider than 700pixels and larger than 150kb so I had to make it smaller as you told me so, hence the bad and small and almost unreadable image on the first page. But I could try to put a new version of it here... let's see..ok here, this is the first one WITH the third leaf.. Also it has all the floor insulation touching the floor..which it shouldn't..correct? ACtually, your floor insulation SHOULD touch the floor; just not a LOT. You want a slight crushing of the insulation when you add the flooring, so that the insulation damps any ringing of the floor. Too much though, and you'll lose isolation. This is kind of a hard thing to describe, because different insulations take different amounts of crush before they get too stiff. Your floor, with two layers of 22mm "massive flooring", is one place you DEFINITELY want some sort of CLD material, such as Green Glue or maybe your "noisekiller yellow glue" - do you have any descriptive info on this stuff at all? Steve

Cheers! I can see why it would be more expensive, but what if the angles or not enough or something is missed in the calculations, isn't it a lot easier if the walls are first built in a squared position, then I measure the interfering frequencies and then I put absorbers or angle the interior walls.. OR :idea: Could I angle the walls towards the floor, I mean that I make the walls facing the floor a bit just like the inside of a cone. Would that work? All the walls would be in a different angle then, right? and the floorspace could be kept at the maximum but the ceiling is smaller than the floor AND also not paralell to the floor. here's a .pdf of NoiseKiller, but it's only in Swedish.. best andreas

"NoiseKiller Gul är ett giftfritt vattenburet dämplim med mycket hög förlustfaktor avsett för laminering av bl.a. golvskivor. Det är möjligt att minska utstrålningen av buller med upp till 16 dB vid resonansfrekvens genom att sandwichlimma golvet enligt principen med NoiseKiller Gul. NoiseKiller Gul skall inte förväxlas med konventionella konstruktionslim då dessa i allmänhet uppvisar mycket låga eller ingen förlustfaktor alls i förhållande till ett viskoelastiskt material. " NoiseKilelr Yellow is a dampening-glue with very high loss, it's developed for laminating floorboards. It's possible to reduce noise with up to 16dB by sandwhiching the floor layers. blah blah yadayada you get the picture. anyway, I think it's worth a try. It also sais things about how to apply it and how long it takes for it to dry and then there's some technical info about its density and that it's fireproof. But I guess you have something similar in the US, right?

Yeah, that's the Green Glue everybody's talking about... Steve

OK, good to know. I just started a new topic here http://www.johnlsayers.com/phpBB2/viewtopic.php?t=5463 about different type of products for floating my construction. Please go there and see if you have any answers. best andreas

Did... 8)