All,

Google Sketchup (http://www.nwrep-intrepid.com/TheaterRoom.skp)

Above is a google sketch up of my theater room. Basically my floor standers are far enough off the back wall (they are rear ported), but due to the size of my screen they are only 1'-2' off the side walls. I realize this presents a problem for reflections/acoustics. What is the best step if the speakers need to be this close? Should I line the lower 1/2 of the side walls with absorption materials out to just beyond the first reflection points?

Any thing else you all can suggest to improve sound?

Get a smaller screen or an AT screen. :D

Actually, 2 feet may be OK but putting absorbent material at that first reflection point on the side wall is essential. Also, definitely use bass management as the SBIR from that wall is significant.

All,

Google Sketchup (http://www.nwrep-intrepid.com/TheaterRoom.skp)

Above is a google sketch up of my theater room. Basically my floor standers are far enough off the back wall (they are rear ported), but due to the size of my screen they are only 1'-2' off the side walls. I realize this presents a problem for reflections/acoustics. What is the best step if the speakers need to be this close? Should I line the lower 1/2 of the side walls with absorption materials out to just beyond the first reflection points?

Any thing else you all can suggest to improve sound?

Gary, I have the exact same problem. My theater was only able to be 12' wide and with the smallest screen I could stand it put my speakers within a few inches of the side wall (I have a couple feet behind). Honestly, I didn't notice a huge problem with front reflections (I know it's less than ideal), but GIK 242's at the first and second reflection point certainly helped to tighten the room up. Pic attached below at framing stage.
http://pic50.picturetrail.com/VOL426/2023328/10303602/147937830.jpg

Those GIK panels sound really tempting...

Do you all think that adding these sound absorption panels at the first reflection will make me hear as if I had a much wider room? I used to have a 16' wide room with no treatments. I was hoping to get at least that performance back if I could ;)

I might just try picking up a few 242s or something. Any other points worth it? From what i've been reading it seems as if adding panels to the room is a bigger upgrade than better wire, etc especially for the cost of the GIKs....

It really depends on who you talk to. I believe adding a lot of panels actually narrow the soundstage a little bit. You are cutting down on the reflection off the walls and you are hearing sound more direct from the speakers. Fortunately your standard panels are not that effective at killing off angle sound reflections. They do more to cut down on the fluttering you get and seem to tighten things up a bit. Another really good alternative is ATSacoustic. They seem to be a hair less money per panel and their shipping rate is much more reasonable. For that size of room 400 dollars would take you a long way in cleaning up the sound.

Thanks for you comments...

Given a 400 dollars budget what would recommend? My mains are 100" inches apart and I am sitting 137" from each speaker assuming a 1.5 foot clearance for each speaker from the side wall...

1) Any change in speaker positioning?

2) What treatments to get? Obviously 2 panels for the first reflections on the side walls. Anything else? Multiple side wall panels or other walls/types?

Thanks,
Gary

How far off the sidewall is the reccomended distance for a front speaker?

How far off the sidewall is the reccomended distance for a front speaker?Depends on how low the speaker's frequency response is and its radiation pattern. SBIR is the LF issue that results in cancellation at a frequency whose wavelength is 4x the distance to the wall. Radiation pattern relates to the magnitude of the first (early) side reflections. Depends.

Thanks for you comments...

Given a 400 dollars budget what would recommend? My mains are 100" inches apart and I am sitting 137" from each speaker assuming a 1.5 foot clearance for each speaker from the side wall...

1) Any change in speaker positioning?

2) What treatments to get? Obviously 2 panels for the first reflections on the side walls. Anything else? Multiple side wall panels or other walls/types?

Thanks,
Gary

The "rule" is, your speakers should be the same distance apart as you are from them. Also they should triangulate so the mains intersect about a ft behind the main listening position. As far as AT go, I have been asking the same q's.
It is recommend to definitely treat the wall behind the mains. You should also treat the first reflection points. The rest is just based on your room requirements. Doing the "clap" test in my room, manifests quite a bit of ringing. It is a dedicated room so there are less objects around to soak up/reflect sounds (hutches, curtains, etc). Your room might be different. I decided to treat the entire front wall, the ceiling, and the second seating row. I'll let you know how much improvement I hear.

Given the width limits, i'd have to move the front speakers like 4 feet off the front wall in order to give me a equilateral triangle. (My seating is 13 feet from the front wall)....
Won't this ruin my imaging?

I can treat the first reflection points with a couple panels. What is recommended for the front wall? Traps in the front corners?

Actually moving the speakers forward should open up the soundstage as well as improve the acoustic response in the room. Having mains directly against a wall can exaggerate lower frequencies and muddy up the sound. I would experiment and do what sounds best while maintaining the rooms function.

I just had a very lengthy discussion with Bryan over at Gik about the same matter. The guy is a class act. I'd recommend giving them a call. Here is the general consensus. You should have a 2" panel (unfortunately due to width I had to limit the reflection point panels to 1") at the first reflection points for each seat. The entire front wall should be treated. I have a screen wall so I ordered 1" OC 703 for the entire front wall and 2" OC 703 for the back wall and rear corners. If you don't have a screen wall, to maintain aesthetics you should at least bass trap the corners and try to install some absorption panels in attractive arrangements along the wall.

Those GIK panels sound really tempting...

Do you all think that adding these sound absorption panels at the first reflection will make me hear as if I had a much wider room? I used to have a 16' wide room with no treatments. I was hoping to get at least that performance back if I could ;)

I might just try picking up a few 242s or something. Any other points worth it? From what i've been reading it seems as if adding panels to the room is a bigger upgrade than better wire, etc especially for the cost of the GIKs....



I have the same type of problem. My room is 15' wide but the screen is a 119". Because of the existing cabinet space, I am forced to place the speakers right next to the walls in the cabinets. I recently orderes the ATS Acoustic panels for the reflection points.http://www.atsacoustics.com/ (http://www.atsacoustics.com/)
Very affordable and built well.

Actually moving the speakers forward should open up the soundstage as well as improve the acoustic response in the room. Having mains directly against a wall can exaggerate lower frequencies and muddy up the sound. I would experiment and do what sounds best while maintaining the rooms function.

I just had a very lengthy discussion with Bryan over at Gik about the same matter. The guy is a class act. I'd recommend giving them a call. Here is the general consensus. You should have a 2" panel (unfortunately due to width I had to limit the reflection point panels to 1") at the first reflection points for each seat. The entire front wall should be treated. I have a screen wall so I ordered 1" OC 703 for the entire front wall and 2" OC 703 for the back wall and rear corners. If you don't have a screen wall, to maintain aesthetics you should at least bass trap the corners and try to install some absorption panels in attractive arrangements along the wall.


Actually the mains are already 3ft off the front wall and the seating is 13.5 feet from the front wall. I can only place the speakers 100" apart in order to maintain that the 1-1.5ft distance from each sidewall to the speaker (1' back of speaker / 1.5 ft. front of speaker as they are toned inward).

This would mean I have to put the fronts FIVE feet off the front wall (and will still be 1/1.5 ft off the side wall). Is this advisable to get an equilateral triangle at all costs (100" between each speaker, speaker to prime seat)? The room is 20' deep so I can't really move the seating up for aesthetic purposes and rear placement. Five feet seems like a lot though considering the far left and right seating will have a main 8 feet in front of them 5ft off the front wall...

I don't mind doing that if its the right way to do it...

Gary, I think a lot of us get too caught up in the numbers and don't really do what sounds the best. I would say experiment with the different positions and do what sounds best to you. Some say an equilateral triangle is the only way to set up your speakers, some say just the opposite. I don't care what the rule of thumb is, if it doesn't sound good to me, it doesn't really matter does it. ;)