Did you go with the Martin Logans? If so the speaker placement method that they recommend on page 8 of the owners manual of the Purity is wonderful. Especially the light reflection used to set toe in. Start from the placement that they recommend and experiment from there.

After trying a number of other methods when I did this with my Martin Logan CLS they really came to life.

Most speaker level signals are not affected by the types of devices you list. If you are in doubt, move either the speaker or the offending device to make certain all is OK.

Different types of speakers will work best in different locations within the room, dipole electrostats will probably not work well in the corners but horn loaded speakers might. However, most rooms have similar requirements for speakers with generally similar construction, all monopole speakers with acoustic suspension enclosures should work well when positioned within a few inches of "ideal" placement in a specific room.

Read a bit about speaker placement. I generally suggest people begin with the WASP placement method and work from there. http://search.yahoo.com/search?ei=utf-8&...ement&type=