Center Loudspeaker Enclosure Location; Center Loudspeaker Enclosure Orientation - Genelec Home Theater System Design And Installation Manual

Residential and home theater loudspeaker systems

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Figure 2. - Mounting the center loudspeaker above an unperforated projection screen

2.5.2 Center Loudspeaker Enclosure Location

Ideally, the center loudspeaker enclosure should be mounted at the same height as the picture so that the

sound comes from the same place as the picture, however this is not always possible as demonstrated

in the following two cases:

Perforated projection screens

The loudspeaker enclosure can be mounted in the center of the picture but there is a compromise

to the frequency response - see Graph 1 in Section 3.7 Acoustically 'Transparent' Screens. Some

perforated projection screens are acoustically more transparent than others, however, this should

be weighed against corresponding compromises in the picture quality.

Large CRT's, rear projecting displays and unperforated projection screens

The loudspeaker enclosure should be placed ABOVE the screen. This will reduce the effects of the

floor reflection as the reflection distance and angle are both increased. Doing this will cause the

ceiling reflection to become significant but this can be easily treated by adding some thin (5 cm / 2"

rock wool) damping material to the ceiling - see Figure 2. The loudspeaker enclosure should never

be placed behind an unperforated projection screen - See Section 3.7 Acoustically 'Transparent'

Screens.

2.5.3

In the case of Genelec's larger three-way center channel systems, the bass/mid crossover frequency is

much lower so the horizontal off-axis cancellations do not occur here. There will however be a cancellation

at the mid/treble driver crossover but this can be overcome by orienting the DCW

crossover cancellation is then in the vertical direction, i.e. not audible due to the fixed listening height.

Two-way systems should normally be positioned vertically to avoid audible off-axis cancellations at the

crossover frequency. When positioned in this way, the crossover cancellation will be in the vertical direc-

tion (not a problem as the listening height is fixed) and the horizontal listening window will be wide and

clean of abnormalities. However, if there is limited space, for example, when large CRT or unperforated

projection screens are used, then the loudspeaker enclosure can be placed horizontally but with this

known compromise. See Section 2.10 Selecting the Right Model for a table on which center loudspeaker

to select for a given room volume and listening distance.

vertically so that the

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