L-Acoustics MTD 112, Руководство пользователя

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MTD 112 34 06/97
To summarize, the MTD 112 should be aimed at the rear of the part of the audience they
are to cover, unlike constant directivity designs which are typically aimed at the center of the
audience part they are to cover.
d) Subwoofer location
- Front of House applications
For F.O.H. applications, the subwoofers will be operated preferably in mono, fed with a
signal from the "sub" output of a MTD 112 LLCa controller. In this case, the subwoofer(s)
shall be located in a central position, approximately at a distance which is equivalent from
the left and right speakers.
Preferably, the subwoofers will be located on the floor, or against a hard wall. If this can be
achieved, one MTD 118 subwoofer per pair of MTD 112 will provide sufficient output. Two
SB 115 would be needed, whereas one SB 218 will be sufficient for 4 MTD 112.
If the difference of distance between the subwoofers and the MTD 112 at a point which is
roughly in the middle of the direct field area reaches 1.7m, acoustic cancellation will occur
around this point at the crossover frequency. This should be compensated by correct
repositioning of the subwoofers. If, for practical reasons, this cannot be achieved it is to be
done virtually with the help of a delay unit for a proper time alignment (5 milliseconds for
1.7m).