[advanced101]

Thinking about my options for the front of my room.  The room is 13' wide and has 3 windows behind the speakers.  Thinking about putting Q7Ds in front of the Left and Right Windows and a Polyfusor in front of the Center Window.  Thoughts?

Current Setup

[poseidonsvoice]

Take a picture of your wall behind you and your side walls. Post that as well.  Bear in mind that your current speakers are not dipoles, they are monopoles through and through. So although treating your front wall is a 'good idea', there may be other walls you should treat first, depending on the polar response of your speaker above 250Hz and below 250Hz.  Are those B&W's? Which model?

Also, please list what treatments you already have up in some detail and which wall it is on. List all the walls, i.e. Front wall, rear wall, side front, side rear, floor and ceiling.  It's hard to tell if you have GIK 244's or Monsters, etc...in the photo.

Best,
Anand.

[advanced101]

The rear of the room is completely open, another 20' behind the listening position.  The front wall is the last one to treat.
244s, Alphas and QRDs on the side walls.  Soffits in the front of the room.
B&W 800D2

[poseidonsvoice]

If that's the case, and with a 20 foot distance behind you...then by the time the wave hits that back wall and travels back, some will hit your ear and some will travel past, hitting the front wall, although at much less intensity. I would vote for absorption on your front wall instead of diffusion, although the Polyfusor can be a nice blend of the two. I don't think pure QRD's/pure diffusion on your front wall (i.e. the wall behind your B&W speakers) will be of benefit.  Moreover, the windows are egresses to the outside world, where acoustically, you lose bass frequencies. This can be a hindrance or benefit depending on how your bass measures in your room (<300 Hz).

Best,
Anand.

[advanced101]

Thanks for your input.

[Glenn Kuras]

You get much more upper frequencies in the back of the room, but diffusion can be pretty nice on the front wall as it will help with imaging. You just want to make sure you do not have boundary reflection nulls (SBIR) which you would then use absorption.  A lot of customers use the Alpha on the front wall as it does diffuse and absorb, so you get the best of both worlds.

[advanced101]

Thanks, went with 3 Polyfusors on the front wall.

[Tyson]

Have you treated your ceiling? If not, that's a giant reflective area that will definitely affect the sound in a negative way.

[advanced101]

Have you treated your ceiling? If not, that's a giant reflective area that will definitely affect the sound in a negative way.

I will be looking into the ceiling next.

[Glenn Kuras]

Have you treated your ceiling? If not, that's a giant reflective area that will definitely affect the sound in a negative way.

Agreed 100%. IMO it can have one of the largest impacts on the room.

[poseidonsvoice]

More importantly, I think the height of the ceiling bears some importance. Mine is 10ft and it is all diffusion. I would imagine a ceiling that is 8 ft or less may benefit more with absorption like GIK 244's or Monsters. The midpoint between the speaker and the listener is an important area to start your treatment. Think about treating 1st reflections on the floor, ceiling and side walls and it all makes sense with forward radiating monopoles.

Best,
Anand.

S = Whoops! See my post below

[Glenn Kuras]

More importantly, I think the height of the ceiling bears some importance. Mine is 10ft and it is all diffusion. I would imagine a ceiling that is 8 ft or less may benefit more with absorption like GIK 244's or Monsters. The midpoint between the speaker and the listener is an important area to start your treatment. Think about treating 1st reflections on the floor, ceiling and side walls and it all makes sense with forward radiating monopoles.

Best,
Anand.

10 feet is getting on the border line of diffusion IF you are looking for the full focus from the speakers. I say IF because some people like the effect of diffusion from the side walls and ceiling.  If that was a mastering or mixing room I would most likely use something like our Alpha panels but tilt them to reflect most of any sound (upper frequencies) to the back of the room. 

[advanced101]

I have 9' Ceilings?  Diffusion or Absorption?

[Glenn Kuras]

I have 9' Ceilings?  Diffusion or Absorption?

Personally I would go with absorption with a 9' ceiling.

[poseidonsvoice]

More importantly, I think the height of the ceiling bears some importance. Mine is 10ft and it is all diffusion. I would imagine a ceiling that is 8 ft or less may benefit more with absorption like GIK 244's or Monsters. The midpoint between the speaker and the listener is an important area to start your treatment. Think about treating 1st reflections on the floor, ceiling and side walls and it all makes sense with forward radiating monopoles.

Best,
Anand.

10 feet is getting on the border line of diffusion IF you are looking for the full focus from the speakers. I say IF because some people like the effect of diffusion from the side walls and ceiling.  If that was a mastering or mixing room I would most likely use something like our Alpha panels but tilt them to reflect most of any sound (upper frequencies) to the back of the room.

Correction!

It's 10.5 feet and actually a mixture of GIK Grid Fusors and GIK 244's, per Bryan Pape  And you are right, understanding the vertical off axis response of the particular loudspeaker at hand along with how the room is going to be used, would be important in making this decision.

Best,
Anand.