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help with further construction off cinema / music room sloped front and rear wall

20K views 77 replies 7 participants last post by  mikesp1 
#1 · (Edited)
help with further construction of cinema / music room sloped front and rear wall

Hello,

I would love to hear some tips for improving my music/ cinema room
Room is about 3.55m X 6.35m x 2.3m high

I am concirned about the sloped front and rear wall and how to treath them well, should i make the front wall completely death?
I have the idea to instal an acoustic transparant projectioj screen about 1.2 m from the front wall and maybe put the front speakers behind the screen.

Right now everything is harsh sounding with no imaging, kind of compressed sounding, boomy aswell. All energy seems to stay in front of room.

I will do everything that is necessary to turn this in a well balanced sounding room. So all your tips are welcome and much appreciated!

by the way here are first pictures and measurement 1/24 octaaf smoothing:

red is front speakers only
green is with sub x-over 80Hz
 

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#2 ·
What EQ is being used?

1.2m baffle wall with acoustic dampening would definitely deaden the boomy sound.
 
#4 ·
#6 ·
Front wall should be 100% dead with something like 2" 703 or ECOSE. Front corners you will want chunk style bass absorbers. A false wall will allow all of that to be done but not seen for a nice clean look.

Rear wall - I prefer to use 6-8" thick panels, potentially with diffusion pending how many rows and how close the seating is to the rear wall to allow the diffusion to develop properly.

The dip around 120Hz is likely a phase cancellation off of the side walls. Could also be the front wall in which case you'd want to thicken up the center of the front wall to address it.

Bryan
 
#7 · (Edited)
Bryan,

thanks for helping me out.
this raises another question: will this treatment have an effect on the rear ports of the front speakers?
Also my subs are frontwall firing and have a passive radiator pointing in listening direction.

if room is 60% music and 40% movie, does the entire frontwall still have to be 100% dead?
 
#14 ·
Ok sorry. You were talking about the room earlier then mentioned "his," so I thought maybe there was another room you were doing. Was just confused. Understand now.
 
#16 ·
waterfalls looks pretty good. 30 will be tough to address. The ply across the front may be resonating.

Looks like the overall sub level is too high.

Pull the mic forward or back a foot and see what happens to the null around 120
 
#17 ·
Tommorow i will try to adres the 120hz null and post here.
Maybe i can tame the 30 hz region by putting one of the subs behind the listening position and leave the other in place, will try tommorow.

What about 120 till 800hz range, i see many dips aswell?
 
#19 · (Edited)
mic 4.2 foot to the front. this is middle of room!
120Hz problem is smoothed out, altough this position gives best sound this seating position is not doable for me bacause of too close to the screen.
Its strange that in my room sitting in the exact middle gives best overall pereformance, i think it has something to do with the sloped ceilings.
I could install a new backwall without sloped ceiling but that would decrease room size by aprox 3.2 foot, maybe the experts can tell me to do so or not?
There is also a doorway without door on the right side of the couch, i can remove that doorway?
 

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#23 ·
It could be either a modal problem or a boundary interaction from reflections on the side walls. Try going back to where you were and measuring a foot off to one side and see what happens.
 
#24 · (Edited)
Bryan,

I have made the frontwall completly dead like you suggested.
There is much more imaging and i can hear things that i could not hear before because of frontwall reflections. It seems treathing the upper wall, from where the sloping begins made a hugh improvement regarding reflections.

But, i find the room sounds too dead right now, its not pleasant listening to music, ht is fine..

As for the 120hz problem, i have not measured but moving my head one or two foot to the right or to the left does not seem to help. Moving head two foot to the front, and bingo everything is there...but that is on middle of room and not doable with movie watching.
Its not only 120hz related, overall performance is much better two foot the front.

What do you think, has it something to do with the one layer sloped back wall? Is it possible the low frequencies go trough this one layer drywall and are stuck in the 2meter cavity bhind?

Also the entire ceiling is one layer drywall with lots of cavity behind, i am thinking this is acting like a helmholz resonator...

I am willing to do anything to make this room sounds great!

THANKS A LOT!
 
#25 ·
Well, 2 channel and HT are different design goals. If moving forward fixes the problem and nothing else has, then moving is the answer. This is why one gets the seat right first, then picks a screen size.

Bryan
 
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