# Treatment and Speaker Placement Considerations - Opinions?



## grinthock (Dec 17, 2010)

Please see attached diagram...

I am looking for the professionals opinion here on both treatment and speaker placement. This room is NOT complete, however I am still partially in design mode (inner shell not even started yet) 

What type of treatments should I consider in my design?

What type of speaker placement decisions should I consider before build? (I need to consider how I will wire and mount speakers, so things like pillars and electrical for subs) 

Thanks...

--J


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## bpape (Sep 14, 2006)

In order, the way to plan a room layout is:

Identify seating requirements and placement.

Based on seating location, identify screen size and type (AT or non-AT will determine limitations of LCR placement. Screen size, type, and where it's going to be (false wall or flat on real wall) will also then determine throw distance requirements and brightness requirements for the PJ.

Identify whether you want optimal surround for the 1st row at the expense of the 2nd or if you want the best compromise for the 2 rows. If the former, use dipole side surrounds located directly to the side of the first row. If the latter, then use the same dipoles but place them approx 1/2 between rows. In either case, you want them at least 6.5' off the floor.

Rear surrounds - I prefer monopoles but there are other preferences. Spec says 135 degrees to viewing axis but that usually puts you too close to a corner. Pending seating width, a good compromise is to align the rear surrounds to the outer arm of the outer chairs.

Sub location - a very good arrangement is to use 2 subs - 1 centered on the front wall and 1 centered on the rear wall. That would require shifting door location and also require walkway to seating be on one side only most likely.

Treatments:

Broadband bass control in the front corners.
Full front wall absorption floor to ceiling with something like 2" OC703
Side wall reflection panels 
Rear wall bass control.

How much of each will be determined by exact room volume, how many seats, expected number of people, actual room construction, etc. - which all impact the starting decay time curve in the room, what the target curve should be, and what is required to bridge the gap between the 2.


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## grinthock (Dec 17, 2010)

Bryan;

Just the man I was looking for...

Is there a sizing guide for the front corner traps? 

For the rear wall bass control, could i keep my door and put one on each side? or direct on the door?

Are you suggesting treating the entire front wall OCO703 ? and then hanging my screen over top?


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## bpape (Sep 14, 2006)

Corner absorbers - as big as you can stand. Usually, they're 17x17x24" triangles floor to ceiling.

You can do that on the rear wall or shift the door over to one side unless that would interfere with surround placement.

Yes - full wall coverage. You can leave out a spot for the screen and mount flat on the wall which will give it an interesting and clean recessed look.


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## grinthock (Dec 17, 2010)

For corner absorbers, I was planning a soffit/pillar right in the front corner (to allow speaker wiring to get down to the floor along with electrical and some other things) so if my corner isn't a real corner, How can I trap it?

Is there a significant different between something like your tri-trap -- triangular trap that basically fills the corner, and a flat panel that spans the corner?


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## bpape (Sep 14, 2006)

Confused on the wiring. If the corners isn't 'real' in terms of sealed hard surfaces, then there's no point in doing double drywall and green glue.

You can certainly do flat panels straddling - they'll just take up a lot more space. For the amount of material it takes to do a 2'x8'x6" panel straddling a corner, you can use the same amount and make 17x17x24" triangular chunks that will top where the rear of the straddling panels would start - and then stick out 6" at 45 degrees.


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## grinthock (Dec 17, 2010)

Bob.... No no, the corners are built like soffits (pillars) on top of the double 5/8 W/GG Wall..

Somehow I have to get speaker wiring to the front stage without piercing the main sound wall.... 

starting to think a false front wall is making more and more sense every second..


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## bpape (Sep 14, 2006)

Got it. 

You could just as easily cut an inch or 2 off the back side of the corner absorbers and slide them down that way.


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## grinthock (Dec 17, 2010)

that's what i was thinking... slide stuff down the inside of the trap instead of building the pillar... and then run behind the stage.

Should the corner trap not touch the wall?


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