Speaker Positioning Advice needed

Hi,

As a new member to Audiogon and a learning audiophile, I am trying to gain as much understanding about designing a good set-up as possible.

SPEAKER SET-UP:

A. How is the optimal distance beween speakers determined? Is it governed by room size, or where the listener is sitting? Currently, my speakers are 60" apart.

What distance do you have your speakers apart?

B. What is the recommended distance in inches to place the speaker from the back wall. I understand this effects the bass / lower frequency response. My speakers have down-firing woofers.

C. Is is recommended that speakers be placed specifically in the corners of the room?

Thanks

Dave