HT Room Acoustics & Speaker Placements

[varuunn]

Hey Guys,

My dedicated home theater is closing fruition. It's taken longer than usual.
The system so far

Sony VPL-HW40ES-B Projector
VideoSecu Projector Mount
150 Inch locally made screen (Swastika Audio/Video)
Crystal Acoustics T3-7.2-UL System
Marantz 7008 AVR
Mac Mini
Monoprice Cables
Drobo FS
Logitech Harmony One.
Lenovo Keyboard & Mouse N5902

I need some help with room acoustics.
I'm attaching pictures for your reference.

One wall (The long length side) has full fabric with some insulation. the wall opposite that are two arches inbuilt so , i cant do much there.
Odd shape of the room means my speaker placements go haywire as you can see from the pictures. Also, the floor has thick carpet on it.
In need help in placement of the speakers and also what can i do so the sound doesn't go psycho. It's a 7.2 system owing to the size of the room.

Any help/ comments would be appreciated.

Varun

 

[varuunn]

Anybody have any opinions, I would be very greatful

 

[koushik]

In a typical room, there are 12 corners. In yours there are 14 if I am right. These all corners or as many as possible needs to be treated with bass traps. Covering as much surface area as possible will only be more beneficial.

After that, target the first reflection points. This reflections from side walls along with the direct sound from the loudspeakers causes a time smearing effect, technically called comb filtering. This effect clarity of sound.

For these acoustic panels, I would suggest home made (DIY) glasswool panels. Bass traps should be >= 4 inches thick and absorbers at the 1st reflection points can be a bit thinner.

Some sort of diffusers helps a lot. Diffuser work as good as absorber and helps in keeping the liveliness in the sound. Try put a diffuser at the back wall.

Start with these things and keep improvising.

Remember, there just can't be enough bass traps in a room.

 

[varuunn]

In a typical room, there are 12 corners. In yours there are 14 if I am right. These all corners or as many as possible needs to be treated with bass traps. Covering as much surface area as possible will only be more beneficial.

After that, target the first reflection points. This reflections from side walls along with the direct sound from the loudspeakers causes a time smearing effect, technically called comb filtering. This effect clarity of sound.

For these acoustic panels, I would suggest home made (DIY) glasswool panels. Bass traps should be >= 4 inches thick and absorbers at the 1st reflection points can be a bit thinner.

Some sort of diffusers helps a lot. Diffuser work as good as absorber and helps in keeping the liveliness in the sound. Try put a diffuser at the back wall.

Start with these things and keep improvising.

Remember, there just can't be enough bass traps in a room.

Thank you!! i shall start figuring out how to make bass traps now

 

[prana]

Agreed that bass always migrates to the corners of a room but realistically speaking you don't need to cover all 12 corners or 14 in your case. Just put them up in the listening range that you are going to be in, so basically 5 bass traps is what you are going to need. You would also want to put the bass traps at a 45 degree angle in the corners creating a cavity for added absorption as it will help absorb more bass than just mounting the traps on the wall.

Covering primary and secondary reflections is definitely going to help you as mentioned by koushik and you would also wanna take care of the ground to ceiling reflections and vice versa.

As far as diffusion is concerned, a good QRD Diffuser would cost you anywhere between 25k to 35k which is a lot of money. You can try going with the poly diffusers but they would only diffuse or rather scatter the high frequencies and not do anything in the mid and low range.

Also as you mentioned that one of the walls have some insulation covered with fabric, i'd suggest over absorption in a room always kills the ambience of the room. It is very easy for the high and mid frequencies to be tamed but not so much with the low frequencies. So make sure you don't over deaden the room taking away all the ambiance of the room.

You can check out some of the stuff available at Sudeepaudio

Remember the key to a good sounding room is not making it over dead.

Cheers