Abbingdon Music Research LS-77 owner manual Positioning, Symmetry and room modes

Section 4 - Positioning

Always try to place the speakers symmetrical in the listening room.

The LS-77 Reference Class Professional Monitor is a Transmissionline port loaded loudspeaker design with no unusual or extraordinary positioning demands, neither in stereo nor in multichannel applications. Despite this, every room will typically have its own particular sound characteristics as shaped by its own acoustic properties. Rooms are also shaped, decorated and furnished uniquely, and therefore remain quite independent regarding options for positioning loudspeakers. AMR suggests that you consult your experienced AMR retailer for further assistance if needed. The following steps are general suggestions that will optimise the speaker placement.

4.1 Symmetry and room modes

It is preferred to establish a loudspeaker layout that provides an adequate and equal left/right image. The basis for this symmetry, meaning that the distance from the listening position to the left and the right speakers should be identical; and if not listening in the near field (1m or less), then additionally identical distance to the side-walls should be maintained.

In all normal rooms certain low frequencies will be boosted or reduced by standing waves developing between parallel walls. If the speakers are placed directly at walls or at half way or quarter way between walls these standing waves will influence the speakers’ performance to the largest extent, hence such placement is best avoided. Equally, it is preferable to locate the listener not at any half way or quarter way point between parallel walls. You may also wish to review the material in Appendix F - Acoustics Background Information for more details.

4.2 Distance between the loudspeakers

AMR recommends a distance between the speakers from slightly less (closer together) to slightly wider (further apart) than the distance from the point centered in-between the pair of speakers and the listening position.

The closer the listening position is in relation to the loudspeakers, the closer the speakers need to be positioned to each other, though as a starting point it is recommended that the speakers be about 2.0 - 3.0 meters apart from each other.

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