Optimally 4 to 5 ft to get the delayed response from the back wave sufficiently separate from the direct signal. If you deaden the wall behind the speaker you might get them a bit closer but I think you then kill the added ambient/ reflective sound and if you are going to do that you're better off getting some good box speakers.
Quad owners
Can you tell me what the minimum distance from rear wall I can place ELS 63,I have two feet would that work?
Thanks
YOGIBOY
Thanks
YOGIBOY