What speaker placement and listener position is optimum?
Box-speakers should be moved away from the walls. Loudspeakers radiate sound from all directions, not just from the front where the drivers are located. The lower the frequencies are, the more the sound will “wrap” around things in the listening room. Because of this “wrapping” effect, the initial sound wavefront from a loudspeaker can reflect off nearby walls, including the wall directly behind the speaker. If the speaker is too close to the rear wall, two things happen: the bass response will be increased due to reinforcement from the back wall and secondary reflections of mid-bass and mid-range frequencies will cause a secondary sound wavefront that is slightly delayed from the initial wave-front to come directly at the listener. Humans can detect slight differences in arrival times like this. This is how humans are able to use their ears to pinpoint the location and distance of a distant sound with some accuracy. In general, if the secondary reflections are very closely timed from
