Speaker placement

[Joe Schmoe]

Every change in speaker placement effects the sound. Sometimes is is an obvious change, other times subtle, but there is always some difference.
For a given room and a given pair of speakers, is there any method (other than trial and error) to determine the ideal placement?

 

[Exit]

There are a number of factors that go into speaker placement. Probably the first is the 5.1 or 7.1 placement recommendations. For subwoofers, there is “drawling for base” to determine best placement. I personally don’t like the subwoofer behind me or in a corner. I like it on the front wall. For regular the front left and right you want them placed for good stereo playback – out from the wall about ear height seated and toed in. For the center channel only a few projector screens are perforated for speaker placement in the center of the screen at seated ear height. Most center channels are centered below the screen angled up or above the screen angled down. The surrounds are place per surround sound setup about 6 feet high. To determine effects of speaker placement changes you could use a sound pressure level meter and measure frequency response changes. I know you probably know all this but I really don’t think there is much more to it. I think if you want to wring out more performance for your system you would want to investigate room acoustic treatments. Done properly they should minimize room effects so the speakers sound about the same despite small movements of the speakers

 

[Joe Schmoe]

I was actually referring to optimizing placement of just two speakers (I didn't make that clear.)
There is a distance from the walls that gives the best balance between bass strength and bass clarity. There is also a best relationship between speaker position and seating position for imaging (the equilateral triangle is a good starting point, but not necessarily optimum.) Finally, there is an amount of toe-in that gives the best balance between image size and image focus.
I adjust these variables by trial and error, but I never know for sure that I have arrived at the ideal combination.

 

[jcPanny]

With a mic and RTA software, you could do frequency response sweeps to determine the effect of the speaker location and the room on the performance. Changing the room (treatments) the speakers, or speaker location would effect the results.