# Advice for acoustic treatment pls



## EccentricDyslexic (Apr 7, 2012)

Hi,

i have built a dedicated room for home cinema and listening to music. It is built out of solid concrete blocks 6" thick. I plan on insulating the walls with 2" rockwool battens held in place by plastic sheeting, all hidden by a black velvet fabric strung ceiling to floor. 
The floor is solid concrete but will be laid with thick carpet underlay and a deep pile carpet. The ceiling is 3/4" plywood screwed to the ceiling joists, above this there is 6" of rockwool insulation and an attic floor of thick chip wood floor boards, again screwed down.

The room dimensions are 22'3" long (6.8m), 13'6" wide and 7'3" high.

I plan on using KEF R700 fronts, R600c Centre, R300 surrounds with an 8 x 18" Fi318 IB Subwoofer mounted on the front wall like in this thread of mine - Opps cant post it untill i have 5 posts if you look on the AVForums site in the Home Cinema DIY forum you will find it near the top of the list of threads, its called "My Home Cinema Project (Imaginative title eh?;-)) "

I'd like some feedback please on whether you feel i may need some acoustic treatments?

Thanks in advance!

Steve


----------



## robbo266317 (Sep 22, 2008)

Hi Steve,

Welcome to HTS.
All rooms will benefit from room treatment and speaker/listening location.

There are many more here who can advise on the best aproach to take.

Cheers,
Bill.


----------



## bpape (Sep 14, 2006)

Having 2" insulation covered with plastic is going to give you likely way too much midrange absorption with pretty much nothing in the bottom end. You'll need some thicker absorption in the front corners and likely on the rear wall and the ceiling given the low height (just at the reflection zone and over your head.

At the reflection points, you don't want things to be high frequency reflective. You'd want them more broadband.

Bryan


----------



## EccentricDyslexic (Apr 7, 2012)

Hi both!

Thanks for the help Bryan, should i mix it up a bit then with some denser rockwool in some places rather than keeping to the 2", and maybe use some polystyrene sheet in some places? Also could use plywood to cover the rockwool, basically i can fit anything over the concrete blocks upto 3"(so it will get hidden by the velvet) so suggestions welcome.

At this stage in the construct i am pretty free to do anything!

By reflection points, what do you mean?:dontknow:

Steve


----------



## EccentricDyslexic (Apr 7, 2012)

Ok, have googled about these reflection points and I need a strip of broadband absorbive material about 6' wide on the side walls and ceiling. Having looked around, it seems like people are using a dense rockwool panel about an inch thick. This will work well for me as I can simply use that in place of the 2" soft rockwool, in these reflective areas. I can even cover with fabric and screw them to the ceiling just in front of, and above the listening position. Does that sound ok Bryan?

The front wall will be difficult to bass trap the corners(you can see why in the thread I referred too) but I can easily make the rear corners or even the whole rear wall a bass trap. What is best to go for?


Cheers

Steve


----------



## bpape (Sep 14, 2006)

1" will do upper mid and high frequencies only. 2" will go a bit lower - down into the male voice range and a tad lower. Thicker is better, especially on the ceiling.

I'm not a fan of the polystyrene in this application. Just fill with insulation and cover with plywood where you dont' want absorption.

Bryan


----------

