2. speakers
  3. 1032140637

Speaker placement for 2-ch AND 5-ch same room

I am building a dedicated room for my gear. I have reasonable architectural freedom, but not unlimited space. Right now we're looking at 15 x 21 x 9 or thereabouts.

I have suddenly realized that I have enough equipment to install two separate systems, one for 5-ch and one for 2-ch. I'm looking for advise as to how to position the speakers. The 2-ch mains are MartinLogan Odysseys; if we go with two systems, the 5-ch mains would be ML Scenarios with Cinema center. The screen is retractable and automated, so I could have the screen drop in front of the Odysseys and place the Scenarios outside of them and slightly in front. I think that putting the big Odysseys outside the Scenarios would start to put them too close to the sides of the room (screen is 92" diag = 7' 6" wide plus tensioning).

My priorities is 2-channel, but I got WAF by making the 5-ch movies work well.

Any other suggestions? Am I nuts?
blw
ozfly
887 posts
 
Blw, with the "remote" constraints, I can only say that you have done a masterful job managing the situation. You still may wish to experiment with moving the HT front speakers later (i.e., away from the main speakers when playing music and then back again for HT -- see if it matters and find a simple, wheeled?, way to do this if it does), but apart from that, it sounds like you are far from nuts.
davehrab's avatar
davehrab
380 posts
 
Here is some food for thought,before speaker placement issues,note that your dimension of 15x21x9 have a commom denominator of 3,meaning all dimensions are divisable by 3.When this occurs(all dimension having the same common denominator) there is a chance of peaks(boosts) and vallies(suckouts)at certain frequencies do to the room dimension excessively renforcing each other.Is it possible to stretch the room to 16x23x9 ? I would contact Audiogon member RIVES,and run it by him.I may be overracting,but an ounce of pervantion is worth a pound of cure.
Good Luck
Dave
davehrab

ozfly
887 posts
 
Davehrab is correct. Dimensions which are exact mutliples do tend to reinforce or boost the same frequencies and create dips in some others -- in a 9x15x21 room, those boosted frequencies are at 188 Hz and 377 Hz with some fairly big gaps or dips in the ranges of 81-107, 161-188, 188-215 and 269-296. If the dimensions are off a bit (e.g., 8'9" rather than 9'), it will affect these in a relatively positive way. My understanding is that anything above about 300 Hz is not a big deal so the only real peak is at 188 Hz and that could be managed with specialized treatments. The 27 Hz gaps might be a bit of a stickier problem. Rives knows more about this and will undoubtedly have more to add. Feel free to ask questions though and I'll give it a shot as will other more learned Audiogoners. Good catch Dave.
blw OP
147 posts
 
Haven't been to Rives' site yet (travelling this week, really busy) but I'll do that. Dropping the ceiling 3" would be no problem whatever - we'll just dig 3" less.

Where is there reading material about this? I know about the stuff at Cardas and the much more general stuff by Robert Harley. I'll definitely dig into the room sizing thing.

Anything else on speaker placement of those five front speakers (2 L, 2R, 1C)?
ozfly
887 posts
 
Try the book Sound Studio Construction on a Budget by F. Alton Everest. Good stuff. BTW, don't drop your ceiling yet, I was talking in generalities. I'll be happy to send you a spreadsheet on these calculations so you can test different dimensional impacts. Let me know if you are spreadsheet savvy and I'll work on it over the weekend to make it a bit less subjective and easier to use. Cheers.
More to discover