Meyer Sound ACHERON LF,L6-20,PTD

Description

Overview

Acheron LF Loudspeaker

The Acheron LF loudspeaker can be paired with the Acheron 80 or Acheron 100 screen channel loudspeaker to deliver the low-frequency headroom required by larger theaters. The self-powered Acheron LF with dual 15-inch drivers boosts the headroom on the LCR channels, converting each Acheron loudspeaker to a system with three low-frequency drivers in an aligned column.

The unique multi-way, gradated design offers smooth coverage and maximum low-frequency impact with all drivers active at the lowest frequencies and each rolling off, one at a time, via the integral active crossover. This technique eliminates interference between drivers that would otherwise occur at shorter wavelengths, enabling the system to maintain ideal polar, phase, and frequency responses throughout the low and low-mid operating ranges. As a result, the system can deliver the necessary power to completely fill a large theater with rich, clean sound, thereby ensuring that the full intensity and nuance so carefully crafted into today’s movie soundtracks reach every listener without compromise.

The Acheron LF was designed exclusively for use with Acheron loudspeakers. The Acheron LF’s 37 Hz to 370 Hz operating frequency range and 133 dB linear peak SPL were carefully chosen to compliment the Acheron. The Acheron LF also features the same high-power 15-inch cone driver used in the low frequency section of the Acheron. Engineered to deliver optimum performance, the high-excursion, back-vented drivers include 4-inch voice coils and are housed in a tuned, vented enclosure that shares the same rectangular footprint as the Acheron.

The Acheron LF is powered by an onboard two-channel class AB/H amplifier with complementary MOSFET output stages. Total output power is 2250 W (4500 W peak) and provides the system with enough headroom to easily accommodate the extreme demands of digital soundtracks.

The optional RMS™ remote monitoring system allows comprehensive monitoring of system parameters from a host computer running Compass® software.

Strategically placed 3/8-inch threaded points on the side corners of the Acheron LF cabinet allow the unit to be mounted to floors with optional mounting brackets. The Acheron 100 and Acheron 80 can be mounted on top of the Acheron LF with uptilt or downtilt with optional stacking brackets.

Specifications

ACOUSTICAL¹	Acheron 80	Acheron 100	Acheron LF
Operating Frequency Range ²	37 Hz – 18 kHz	37 Hz – 18 kHz	37 Hz – 370 Hz
Frequency Response ³	38 Hz – 17 kHz ±4 dB	38 Hz – 17 kHz ±4 dB	38 Hz – 340 Hz ±4 dB
Phase Response	700 Hz – 17 kHz ±30°	700 Hz – 17 kHz ±30°	60 Hz – 230 Hz ±30°
Linear Peak SPL ⁴	135 dB with crest factor of 18.5 dB (M-noise), 134 dB (Pink noise), 136 dB (B-noise)	134 dB with crest factor of 18 dB (M-noise), 133.5 dB (Pink noise), 135 dB (B-noise)	133 dB with crest factor > 11 dB (M-noise), 133 dB (Pink noise), 133 dB (B-noise)
COVERAGE
Horizontal Coverage	80°	100°	N/A
Vertical Coverage	50°		N/A
CROSSOVER
	580 Hz⁵		200 Hz⁶
TRANSDUCERS
Low Frequency	One high-power 15-inch cone driver with neodymium magnet; 4 Ω nominal impedance	Two high-power 15-inch cone drivers with neodymium magnets; 4 Ω nominal impedance
High Frequency	One 4-inch diaphragm compression driver; 8 Ω nominal impedance
AUDIO INPUT
Type	Differential, electronically balanced
Maximum Common Mode Range	±15 V DC, clamped to earth for voltage transient protection
Connectors	XLR 3-pin female input with male loop output; optional XLR 5-pin connector to accommodate both balanced audio and RMS signals.
Input Impedance	10 kΩ differential between pins 2 and 3
Wiring	Pin 1: Chassis/earth through 220 kΩ, 1000 pF, 15 V clamp network to provide virtual ground lift at audio frequencies Pin 2: Signal + Pin 3: Signal – Case: Earth ground and chassis
Nominal Input Sensitivity	10 dBV (3.2 V rms) continuous is typically the onset of limiting for noise and music
Input Level	Audio source must be capable of producing of +20 dBV (10 V rms) into 600 Ω to produce the maximum peak SPL over the operating bandwidth of the loudspeaker.
AMPLIFIER
Type	Two-channel with complementary MOSFET output stages (class AB/H)
Total Output Power⁷	3370 W peak		4500 W peak
THD, IM, TIM	< 0.02%
Cooling	Forced air cooling, two internal fans (one ultra low-speed fan, one reserve fan)
AC POWER
Connector	250 V NEMA L6-20 (twistlock) inlet or IEC 309 male inlet
Automatic Voltage Selection	Automatic, two ranges, each with high-low voltage tap (uninterrupted)
Safety Rated Voltage Range	95–125 V AC; 208–235 V AC, 50/60 Hz
Turn-on and Turn-off Points	85–134 V AC; 165–264 V AC
CURRENT DRAW
Idle Current	0.71 A rms (115 V AC); 0.38 A rms (230 V AC); 0.79 A rms (100 V AC)		0.64 A rms (115 V AC); 0.32 A rms (230 V AC); 0.85 A rms (100 V AC)
Maximum Long-Term Continuous Current (>10 sec)	5.8 A rms (115 V AC); 2.8 A rms (230 V AC); 6.3 A rms (100 V AC)		8.8 A rms (115 V AC); 4.4 A rms (230 V AC); 10.0 A rms (100 V AC)
Burst Current (<1 sec)⁸	6.4 A rms (115 V AC), 3.2 A rms (230 V AC), 7.2 A rms (100 V AC)		19.0 A rms (115 V AC), 9.5 A rms (230 V AC), 22.0 A rms (100 V AC)
Maximum Instantaneous Peak Current	26 A peak (115 V AC), 14 A peak (230 V AC), 28 A peak (100 V AC)		39 A peak (115 V AC), 20 A peak (230 V AC), 45 A peak (100 V AC)
Inrush Current	7 A peak (115 V AC), 7 A peak (230 V AC), 10 A peak (100 V AC)		7 A peak (115 V AC), 7 A peak (230 V AC), 10 A peak (100 V AC)
RMS NETWORK (OPTIONAL)
	Two-conductor twisted-pair network that reports all operating parameters of amplifiers to system operator’s host computer.
PHYSICAL
Dimensions	W: 31 in (787 mm) x H: 35 in (889 mm) x D: 20.5 in (521 mm)		W: 31 in (787 mm) x H: 36.18 in (919 mm) x D: 20.5 in (521 mm)
Weight	173 lb (78.5 kg)		185 lb (83.91 kg)
Enclosure	Premium multi-ply birch with slightly textured black finish
Protective Grille	Powder-coated, hex-stamped steel with black mesh
Rigging	3/8-inch threaded points on side corners for optional bracket adapters that allow the Acheron to be mounted to floors with uptilt or downtilt, as well as on top of the Acheron LF (also with uptilt or downtilt)