L-Acoustics MTD 112, Owner'S Manual

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MTD 112 32 06/97
* The "control" display LED's indicate that the threshold of limiters operation has been
reached. They are assigned to the two channels independently.
*
The "signal" display LED's indicate that a signal is present at the input, the threshold
being set at -15 dB.
*
The power switch is provided with a led display indicating that the unit is being mains
supplied.
To summarize, the mono output provides 2 configurations to the user :
1 . Sub-Low extension :
The 2 front panel switches, are respectively in position SUB and X-OVER and
the rear panel switch is in position OUT PHASE.
2 . Central full range extension :
The right switch of the front panel is in position SUM.
The selection of the left switch depends on the choice of use.
The rear panel switch is in position IN PHASE.
6.4 SOUND SYSTEM DESIGN
The art of designing a sound system is a profession in itself, and the relevant skills and
knowledge are supported by a few pertinent books. It is therefore neither to be described
extensively, nor even summarized in a product user manual.
Further, we would like to underline how useful it is to involve a specialized engineer in any
sound system design, whether he is an independent consultant or a house engineer, as the
best products can produce the worst results if unproperly set-up.
The object of this paragraph is to help the sound system designer in his task when MTD
112 systems are to be installed, simply by reminding a few features which are specific to
this type of design.
a) Passive, "processed".
The MTD 112 are practically very loud with respect to their size, and are capable of
covering wide audience areas. There is no "magic" behind this: The MTD 112 LLCa
controller ensures that the signal fed to each driver is acceptable for this driver, and this is
performed in real-time. This means that there is no need to keep a safety margin, when
using the MTD 112. Even an inexperienced user can use the MTD 112 system at its full
potential without risk.
The only true risky situation occurs when the amplifiers are clipping, providing very high
frequency components at full level. This is likely to occur when the amplifiers driving the
loudspeaker are underrated, that is, not powerful enough.
MINIMUM REQUESTED AVAILABLE VOLTAGE OUTPUT OF THE AMPLIFIERS FOR
DRIVING THE MTD 112:
49 volts permanently, continuously for more than 10 seconds (300 W / 8
Ω
;
600 W / 4
Ω
)
60 volts for a few milliseconds (450 W / 8
Ω
; 900 W / 4
Ω
)
b) Single source
Due to its dual-concentric technology, the MTD 112 can provide a true point-source. This is
a great advantage which is lost when coupling enclosures together. Although it is feasible,
IMPORTANT NOTICE: DO NOT CONNECT THE LOUDSPEAKER IN PARALLEL WITH
THE "SENSE" CABLE AT THE OUTPUT OF THE AMPLIFIER!