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Farkinca71 3rd June 2020 11:28 AM

Too dampened ht room, advice needed
 
8 Attachment(s)
Dear All,

I have a 90% ready ht room, I did some measurements with REW, and realised that the RT60 value is 150 ms from 3-4-500 hz and above on all of the channels except the sub. More details follows.
The room dimensions are width : 374 cm, height: 230 cm and length: 612 cm.
The floor is carpet and 6 mm rubber floor. Ceiling is halltex soundproofing tiles.
Walls are made of 10 cm rockwool 70 kg/m3. one layer of Osb and one layer of blue accoustic gypsum sheet. Behind the at screen rockwool absorption panels.
I will attach pics about the left front chanel, but the RT60 value is basically the same for all of them. Finally I will include the whole rew file , maybe it will be useful for somebody willing to help me !
I need your help to decide how badly is dampened my room, and how can I improve the above mentioned RT60 value. Around the side walls I have not installed any treatments, so I am sure I will have to install some. In the first run, I want to install some reflective surfaces on the sidewalls, like plywood, to increase the total amount of reflective surfaces. Please, advise me.

Thanks a lot in advance for your prompt help ! :)

BR,

Zoltán

Farkinca71 3rd June 2020 12:18 PM

Pictures about the current state
 
3 Attachment(s)
Here are some pics about the current state with the temporary seatings.

Farkinca71 3rd June 2020 12:53 PM

And finally here is my equipment list

Denon avr-x4500h
Digital Projection dVision 35 WQXGA
146” Screenline, Microperforated
Speakers: K.C.S.
LCR: 3 * S-2000 (C-115-PLF) Crown CDi 4/300
Surround: 10 * SR-12-N (THX) Crown 1002, 1502
Sub: Behringer NX3000D - 2 * C-218-A (THX)

thethrillfactor 4th June 2020 04:44 AM

A couple of things in your measurements:

1) You are driving the sub too hard. Your distortion and noise figures in the sub low end are too high. Something is wrong at 50hz which looks like a grounding problem.


2) Is your room too dampened?

The recommended decay for a listening room your size is around .2sec
Right now in the high end your in the sub .15 sec range already. Adding more trapping will dampen it even more, so it has to be treated so it doesn't absorb above 300hz.

3) There are weird vibrations (350hz) and resonances that need to be take care of.

Treatment is needed for the 1st order modes, 1-0-0, 0-1-0, 0-0-1 as the decays are too long.

Farkinca71 4th June 2020 07:34 AM

Hello

First of all, thank You for the fast reply ! kfhkh

Quote:

Originally Posted by thethrillfactor (Post 14780259)

2) Is your room too dampened?

The recommended decay for a listening room your size is around .2sec
Right now in the high end your in the sub .15 sec range already. Adding more trapping will dampen it even more, so it has to be treated so it doesn't absorb above 300hz.

I am trying now to install reflective surfaces wherever I can, e.g. between the columns underneath the black fabric. I do test plywood and tiles. Moreover, I will install perforated HDF sheets in front of the corner bass traps. Thus trying to increase the RT60 up to 0.2. I am on it.

Quote:

Originally Posted by thethrillfactor (Post 14780259)

3) There are weird vibrations (350hz) and resonances that need to be take care of.

Where and what may be the cause ?

Quote:

Originally Posted by thethrillfactor (Post 14780259)

Treatment is needed for the 1st order modes, 1-0-0, 0-1-0, 0-0-1 as the decays are too long.

With this, You completely lost me. If the decay is too long, somewhere I should place absorption, right? Any guidance for finding that spots ?

Once again, thanks a lot for help and patience !

Br,

Zoltan

Jens Eklund 4th June 2020 09:05 AM

https://www.gearslutz.com/board/stud...l#post14713531

https://www.gearslutz.com/board/stud...l#post14291770

Farkinca71 4th June 2020 07:15 PM

Thanks a lot, I will verify the links kfhkh