This is an amazing resource that I had no idea it existed. Many-many thanks for being around!
I am currently researching and planning for the acoustic treatment - and partial sound isolation - for a small TV post-production Dolby Atmos premixing room.
Somebody will come and calibrate the room. Part of the calibration has been to create a schematic about where the all the speaker’s acoustic axis should be positioned. This has been made and I already have it.
TO BEGIN WITH:
0.1 I cannot massively interfere with the structure of the building or the room.
0.2 Anything I do to improve the acoustics I’d need to be able to someday revert to how the room was when the keys were handed over to me.
0.3 I understand that they will be compromises along the way but I am happy to go along anyway.
1. PRELIMINARY BUILDING & ROOM INFORMATION
1.1 The building has been constructed from very-very thick concrete. I’d dare say bunker-quality, in an A-graded listed building.
1.2 Luckily the adjacent rooms are being used for storage. One of them will be the machine room.
1.3 The room below is an ad-hoc meeting room.
1.4 There is no room above me (roof)
1.5 The room has a window (on the the 2.27m side. see below for the room dimensions) facing the exterior, and needs to be isolated as much as possible.
1.6 Adding to the above, I’d be happy to construct an additional stud wall in front of the window, to further isolate from any exterior noise coming in the room.
1.7 The wall - were the window is - starts sloping at about 2.4m height.
1.8 The room has a very think carpet layer which I am thinking of changing to laminate without removing the carpet. I will be layering material on top.
1.9 The height of the room is also a bit “unusual” (4.24m)
1.10 At this first, v1 of the installation, a big LED TV will be used instead of a projector. Hence, no perforated screen for the LCR speakers to mount behind will be used.
2. ROOM DIMENSIONS:
The room dimensions are perhaps a bit irregular and are:
WIDTH: 2.27m
DEPTH/ LENGTH: 4.86m
HEIGHT: 4.24m
3. SPEAKER INFO:
3.1 The speaker configuration would be 7.2.4.
3.2 The full frequency speakers need to be - ideally - able to achieve at least 100db max Peak SPL.
3.3 All speakers are made by Genelec and are:
7.0.0 - Genelec 8040Bs,
0.0.4 - Genelec 8030Cs,
0.2.0 - 1x Genelec 7060 and 1x 7350).
3.4 The speakers will be calibrated using the Avid MTRX/ DAD AX-32 SPQ card.
4.1 ISSUE TO ADDRESS 1: FILL THE WINDOW CAVITY TO REMOVE/ REDUCE EXTERIOR NOISE:
As per 1.5 this particular window the recess is 18cm. I am not sure if allows for enough material.
I’ve done this in the past with great success using: Rockwool, plasterboard, Techsound, Rockwook, 2” MDF, Rockwool) but the window recess was much bigger.
Questions:
4.1.1 Any suggestions there?
4.1.2 If it doesn’t then, I am thinking of the possibility to construct another stud wall or just another layer of Rockwool and acoustic transparent fabric.
4.2 ISSUE TO ADDRESS 2: REDUCE (as much as possible give the fact that I cannot massively structurally interfere) SUBWOOFER FREQS TO THE ROOM BELOW
As per 1.8. I have been advised to use something like:
Rigid Rockwool (I am thinking of Rockfloor by Rockwool)
Double layer of T&G Plywood
And ideally, I’d go with laminate flooring on top.
Questions:
4.2.1 Would this have any success in minimising/ reducing structural noise to the room below?
4.2.2 Is the idea to use laminate flooring acoustically a better one?
4.2.3 Any other recommended alternatives?
4.3 ISSUE 3: MOUNTING THE CEILING SPEAKERS AND THE LED TV
I already have the appropriate ceiling mounts from the speaker manufacturer and a Ceiling Mount VESA for the LED TV.
My idea has been to get three 2.4m custom made beams. One would be for the LED VESA ceiling-mount (that has adjustable length) and the other two for the two pairs of speakers.
The ceiling mount plate is about 170mm wide so the minimum dimension for these beams would be 170mm x 170mm x 2400xx. I’d be happy with 200mm x 200mm x 2400mm.
I’ve looked into using scaffolding pipes instead and it is possible but aesthetically rather displeasing. I would like a bit of wood “feel” in the room if possible.
Questions:
4.3.1 Does anyone know where to find such timber in the UK? I’ve spoke to many of the usual timber merchant around and so far, nobody does that custom size.
4.3.2 I do not really know how to mount them on the wall. I am assume that there is not a joist hanger of sorts for these dimensions. Would anyone have any ideas?
4.3.3 The total weight of the two speakers - plus the ceiling mounts - is about 20Kgs per beam. My understanding is that this is nothing for structural timber like this so no chance of shagging due to weight overload. Would this be correct?
4.4 ISSUE 4: CORNER/ BASS TRAPS
Unfortunately, as the room is quite narrow, I would not like afford really chunky bass traps. The door one the one side, the window on the other, and the speaker placement (wall-mounted) makes the any thinking wider borderline impossible.
The fairly stock 60cm width (as a lot of off the shelf solution come at) is possible though.
I was ready to embark and make triangular corner traps from top to bottom. But then, I stopped to check with you guys first
Questions:
4.4.1 Are a triangular corner trap a good idea for such a room?
4.4.2 If 4.4.1 is a yes, what would be advisable to use as the filling material?
4.4.3 I am also now thinking about the Vicoustics Victotems. Anyone have any opinions on these specific ones?
https://vicoustic.com/product/victotem- ... ght%20Grey
4.5 ISSUE 5: CLOUD TRAPS AND CEILING ABSORPTION
From a previous installation, I have several of the GIK bass traps 120cm x 60cm
Questions:
4.5.1 Could I use them to create a cloud for sound absorption and further reducing the RT?
4.5.2 What would be recommended to affix on the ceiling and or the wall-to-ceiling corners?
Thanks to anybody who is taking the time to read this!