Acoustic treatment at pre construction - asking for guidance

[Damian1973]

First time poster, long time lurker - I would just like to say how informative this website is.

We are constructing a new single side extension to our property and its primary use shall be a home theatre.

The room dimensions are to be 5.9M x 3.6M x 2.4M and essentially it’s breeze block, insulation, stud and plasterboard.

We are aiming for a 7.2.4 Atmos configuration comprising of -

AV X6800H

Sub SVS SB 3000 x 2

L/R KEF R3 Meta

C KEF R6 Meta

Surround KEF R8 Meta x 4

In ceiling (TBC) x 4

Initially i have been looking at treatment from GIK acoustics but their recommendation of 4 x Soffit Traps, 4 x Clouds and multiple panels of reflection, absorption and scatter has me concerned regarding the aesthetic.

Whilst we accept that this will never be a perfect room, we do wish to strike a nice balance between sound and design.

Would it be possible to avoid some of their surface treatment effectively during construction and have Dirac and carpets, furnishings help out?

 

[ErVikingo]

You can reduce the need for treatments with careful consideration of ratios of L x W x H and also IMHO not having perfectly parallel surfaces.

Also follow a LEDE principle (live end dead end) meaning absorto e or difussive surface facing opposite reflective wall. Say for example ceiling is reflective counteracted by deep pile carpet and stuffed furniture.

This has worked well for me in 3 rooms so far. Now some prefer a dead room for movies (multichannel).

Careful choice of materials helps! Also, you could get rid of corners this reducing areas for accumulation of energy.

In theory if you follow the so called golden ratio you would have a great start.

The ratio (“phi”) of height x 1.6 is width and height x 2.6 is length.

Regarding treatments (and I have a lot) don’t forget that you can hide them. My prior listening room had all walls covered in Guilford of Maine fabric hiding treatments.

My neighbor made “ pockets “ on the walls 8” deep on the walls meeting in corners and followed them with Owen’s insulation and covered them in fabric. On the side walls he did something similar but only 4”. His rear wall has an intricate wall to wall bookcase filled with his cds dvds etc which act as a diffuser!

 

[sneakmasterG]

First time poster, long time lurker - I would just like to say how informative this website is.

We are constructing a new single side extension to our property and its primary use shall be a home theatre.

The room dimensions are to be 5.9M x 3.6M x 2.4M and essentially it’s breeze block, insulation, stud and plasterboard.

We are aiming for a 7.2.4 Atmos configuration comprising of -

AV X6800H

Sub SVS SB 3000 x 2

L/R KEF R3 Meta

C KEF R6 Meta

Surround KEF R8 Meta x 4

In ceiling (TBC) x 4

Initially i have been looking at treatment from GIK acoustics but their recommendation of 4 x Soffit Traps, 4 x Clouds and multiple panels of reflection, absorption and scatter has me concerned regarding the aesthetic.

Whilst we accept that this will never be a perfect room, we do wish to strike a nice balance between sound and design.

Would it be possible to avoid some of their surface treatment effectively during construction and have Dirac and carpets, furnishings help out?

You might find these links helpful:

Sound Reproduction

A Routledge Companion Website

routledgetextbooks.com

Sound Reproduction

A Routledge Companion Website

routledgetextbooks.com

 

[alex-z]

Start with the construction, good noise isolation is only possible at that stage. Staggered studs and 5.5" insulation is vastly superior to standard single row studs and 3.5" insulation, especially at low frequencies. Doing a mixed material wall also helps a good amount, Sonopan is particularly effective but availability is poor outside Canada.

If you are concerned by aesthetic you could do a fabric cover. Materials like denim are borderline acoustically transparent, it is possible to hide all your speakers and acoustic treatment behind a false wall.

Carpet and drapes don't have much impact outside of the treble region. Furniture can provide some mid-range absorption.

Dirac doesn't correct room reflections unless you are paying extra for the ART version, and even that only works at low frequencies. It is good software but not a replacement for physical acoustic treatment.

I would recommend ported subs for a home theatre, the extra headroom below 30Hz is valuable. I would also switch away from the R8 Meta for surround duty, they are quite expensive relative to their SPL capability. Perhaps use recertified KEF R3 instead, those sell for $1400 per pair.