I am setting up my theater room using the following:

Pioneer Kuro 60 inch plasma 150fd
B&W 804s for fronts
HTM3S center
Ds8 dipolar rears
Sunfire Signature EQ sub
NAD preamp and amp


I want to get the best sound possible. I will sit 10' from the monitor so that i am equal with the distance from my fronts from one another. I am trying to create as close to an equalateral triangle as possible.

!) QUESTION- That will put my fronts around 1' from the side walls. Is that enough? They will be around 2 1//2' from front wall.

2) Because I am only sitting 10' from monitor I will be 13' ft from my back wall. That seems pretty far away from the rear wall.

a) Is that an acoustic issue? Does it help or hurt being so far away?
b) What kind of acoustic treatment should I use on the back wall- absorbant shields or dissonance or none?

3) I want to do a good job with acoustic shielding.

a) I am thinking a shield on the front wall behind each front speaker (excluding center).
b) First reflection points on side wall using mirror trick.

1) Should i do ceiling first reflection point (flat drywall)?
2) I have carpet on the floor.

c) What thickness should I use on the absorbant shields 1" or 2"?

d) How important are bass traps and where should I put them in the top 4 corners or just the middle of the four corners?


THANKS FOR THE ADVICE!!!!!!!!!!!!!!!!!!

I quick answered in the other thread...

1. That seems good, your optimal speaker placement should follow along Dolby recomendations. With that said? Most people do best they can with their screen wall and front sound stage. There are trade offs on how far apart, tow, how high/low ther sit, ect..ect.. when using multiple seating to the front sound stage in particular.

2. In 5.1 the distance to the rear wall usually has little to no bearing, the total volume of the room does impact your equipment choices though.

3. Shielding?? Generally you want gom panels and/or bass traps... Your attempting to absorb the sound at your reflection points. Serious gom panel design will require some running it through some software with yoru room input into it as well.

Most don't use such panels on their cieling. Maybe not a bad idea, but I'd go in first with out it.

Placement of traps can be tricky, many do just end up putting them in the corners. This can by chance still result in odd dips at the sweet spot. But your room seems pretty large front to back so I doubt you would have that happen.

Placing treatments just in corners will only address a few of the issues and ignore many others.

The front wall should be 100% dead. There are a variety of reasons for this but it should be done.

Rear wall can cause some bass anomolies and nulls based on distance from ears to wall behind. Plan on thicker treatment on the rear wall to avoid this.

Side wall reflections between you and the speakers need to be dealt with. You'll have an entire area to cover as you have reflections for each seat off each wall for each speaker. e.g. - 4 seats, 3 people, 12 points on each wall.

If the room is 23', then your ears should be approx 8'9" from the front wall or approx 14' 3" from the front wall to do the best job of avoiding the length modes of the room. 8'9" is not a bad distance from a 60" screen.

Now that you've dealt with all of that, you still need to look at where the decay time is in the room across the entire spectrum considering people, furnishings, room construction, etc. and see where you stand in comparison to where you should be.

Bryan