Garden Drum Room Build (page 2) | John Sayers’ Recording Studio Design Forum archive

Ushmurray wrote:
Hi Paul, I just had a go at Gregwor's calculator again. I've got a two leaf system, Leaf 1: Knauf Soundshield Plus 15mm TecSound SY 100 Knauf Soundshield Plus 15mm ProSound Reducto Clip 100x50 stud filled with Knauf Earthwool RS60 Leaf 2 is cavity wall. 100mm sand and cement block 100mm kingspan insulation 100mm sand and cement block I could be doing this totally wrong but what confuses me about this is, I fill in "Leaf 1 Sheathing" horizontally , it doesn't list the products i'm using and it doesn't list any Knauf RS60 or similar product. The "leaf 2 sheathing" line doesn't have concrete block as an option so i have to leave it blank. I fill in "Leaf 2 support material" as sand and cement brick 200mm. My results give me a TL of Leaf 1 based on products i'm not using and no acoustic insulation rs60 I don't get a TL of Leaf 2 because it can't be filled in. Either i'm doing something wrong or this calculator just wont work for my construction. Here's my attempt to fill it in
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Looks like you're using a slightly different version to me, I'm using this version: https://docs.google.com/spreadsheets/d/ ... 1543869474 You need to go to file and make a copy first before you can edit it. Yes it doesn't have every single product, but all you need to do is choose anything as the product, then select custom, and then put the surface density for each in the box beneath. So, as long as you know the surface density for each layer of your leaves then it doesn't matter what it's called in the product menu. You do not need to put the insulation in as part of the leaf as it will work out the cavity resonance with and without insulation for you, the type of insulation in the cavity has a negligible effect on TL. For the concrete block support structure you can choose "PCC Concrete (without steel)" for example, then go to the bottom tabs where it says "data" then find box O, 22 and change the value to the surface density of your concrete blocks (kg/m3) then go back to the TL Calculator tab and to see the results. The "GAP BETWEEN SUPPORT STRUCTURE MATERIAL" is the gap between your concrete blocks and the studs. Hope that helps, Paul

Hi Paul, That's helped me tremendously , thank you so much. :D I've entered the wall info as follows Leaf 1 : Knauf Soundshield 15mm @ 12.85kg/m2 Tecsound Sy100 5mm @ 10kg/m2 Knauf Soundshield 15mm @ 12.85kg/m2 Leaf 1 support : 2 x 4 stud Leaf 2 support : PPC Concrete w/o steel Gap between support structure : 50mm See results below

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For the doors i've entered Leaf 1 : (outer door, 100mm sand) Birch ply @ 9k/m2 100mm Dry sand @ 160kg/m2 Birch ply @ 9kg/m2 Mdf @ 11.11kg/m2 Leaf 2 : (Inner door, 50mm sand) Birch ply @ 9k/m2 50mm Dry sand @ 80kg/m2 Birch ply @ 9kg/m2 Mdf @ 11.11kg/m2 Gap between support structure : 150mm

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So if i've done this right it looks pretty good to me. The doors outperform the walls slightly , i'm quite surprised at that. I'm getting 70db TL down to about 160hz and falling to about 40db TL at 50hz. What do you think, is this is a good result?