L-Acoustics MTD Series, Руководство оператора

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L-ACOUSTICS MTD Manual V1.2 11/30/2004
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1.4 MTD112b SPECIFICATIONS
The MTD112b is a passive, two-way, coaxial full range loudspeaker containing one direct radiating,
bass reflex-loaded 12 inch low frequency transducer and one 1.4 inch exit, 3 inch voice coil diameter,
titanium alloy diaphragm compression driver. As a full range system, the frequency response is 70 Hz
to 14 kHz with less than ± 3 dB variation and the usable bandwidth is 55 Hz to 16 kHz (-10 dB).
The cone body of the low frequency component provides pattern control loading of the compression
driver, yielding an 85-degree (± 20-degree) conical dispersion pattern that is axi-symmetrical. The 2
nd
and 3
rd
order passive filters employed in the MTD112b provide a 1.2 kHz crossover point between
low and high frequency components. Long term power handling is 450 Wrms at a nominal 8 ohm
impedance and connection to the loudspeaker is made via two parallel 4-pin Neutrik Speakon
connectors.
The MTD112b has a truncated wedge shape with a curved front profile. When used on its rear side,
the front baffle of the enclosure is oriented at a 45 degree angle with respect to vertical, allowing the
enclosure to be used as a floor monitor.
Dimensions are 54 cm (21.3 in) high, 41 cm (16.1 in) wide at the front of the enclosure, 16.5 cm (6.5
in) wide at the rear of the enclosure and 37.5 cm (14.8 in) deep. Enclosure weight is 26.5 kg (58.4 lbs)
and cabinet construction consists of 18 mm (0.70 in) and 30 mm (1.18 in) Baltic birch plywood with
internal steel bracing and joints that are sealed, screwed and rabbeted. The finish is maroon-gray high
resilient paint and the front of the enclosure is protected by a black powder-coated, 1.5 mm (0.06 in)
thick steel grill that is covered with 10 mm (0.4 in) thick acoustically transparent open cell foam.
The MTD112b has a 36 mm (1.42 in) diameter pole mount socket mounted on the bottom side and a
single stud anchor plate mounted on the rear side along with four threaded inserts for attachment of
an optional Omnimount bracket. Four recessed attachment locations are available (two on each top
and bottom side) for rigging the enclosure with the optional ETR1 adjustable U-bracket accessory.
The MTD112b is used with the LLC112b-st stereo analog controller that monitors power amplifier
outputs and employs sense return processing to provide thermal protection and cone excursion
limiting for the loudspeaker components. The analog controller provides band limiting and corrective
component equalization with three settings that are designed for front-of-house, floor monitor or
two-way operation with subwoofers. The LLC112b-st controller also performs signal summation of
the two input signal channels and provides a line level output signal with selectable band limiting and
equalization for use of the MTD112b in conjunction with SB115, SB118 or SB218 subwoofers.
Figure 4: MTD112b passive 2-way (12” LF + 1.4” HF) coaxial loudspeaker