Meyer Sound ACHERON-100, ACHERON-100-RMS, ACHERON-80, ACHERON-80-RMS, ACHERON-LF Data Sheet

DATASHEET

31.00

[787mm]

20.50

[521mm]

35.00

[889mm]

21.00

[533mm]

20.00

[508mm]

10.75

[273mm]

ACHERON® : Screen Channel Loudspeaker System

Acheron 100

At the heart of Meyer Sound's EXP line of cinema
products is the Acheron high-performance
screen channel loudspeaker. Optimized for
installation behind perforated screens, the two­way loudspeaker combines the advantages of
self-powered technology and innovative horn
design to deliver exceptional, precise coverage
for the left, right, and center sound channels for
cinema.

The Acheron loudspeaker is available in two
full-range models: the Acheron 100, with a
100-degree horizontal by 50-degree vertical
horn, which is ideal for wide theatres; and the
Acheron 80, with an 80-degree horizontal by
50-degree vertical horn, which is suitable for
more narrow theatres and re-recording stages.

The Acheron horn (patent pending) was
specifically designed for cinema use and features
a very soft roll-off outside the extremely well
behaved coverage angle. The horn is fixed within
the enclosure to ensure an accurate acoustic
crossover, phase response, and an incredibly

Dimensions

Weight

Enclosure

Mounting

31.00" w x 35.00" h x 20.50" d
(787 mm x 889 mm x 521 mm)

173 lbs (78.47 kg)
Premium birch plywood
Low gloss, black textured

Finish

3/8" threaded points on side corners for optional
bracket adapters, which 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)

consistent vertical pattern between the low
and high frequencies. The Acheron’s 580 Hz
crossover point places most of the dialog in the
horn, which is ideal for cinema applications.

Boasting a frequency response of 38 Hz to
17 kHz at

±4 dB

, as well as a generous peak
output of 139 dB with very low distortion, the
Acheron stands up to the most demanding
of digital soundtracks, maintaining a wide
dynamic range and full fidelity. Designed and
manufactured at Meyer Sound's headquarters
in Berkeley, California, the Acheron's drivers
include one 15-inch low-frequency neodymium
magnet cone driver and one high-frequency
4-inch diaphragm compression driver. The
drivers yield uncompromising quality and
full bandwidth, making the Acheron suitable
for small and medium theatres, re-recording
stages, and production and postproduction
facilities.

The Acheron's sophisticated onboard amplifica­tion produces consistent and predictable results

in any system design. The proprietary Meyer
Sound power amplifier is a two-channel, class
AB/H amplifier with complementary MOSFET
output stages that yields a total output of
1685 W (3370 W peak). Built-in signal processing
includes an electronic crossover and correction
filters — to achieve a flat phase and frequency
response — along with driver protection circuit­ry. The self-powered design not only ensures
consistent results but also simplifies installation
in both new and existing rooms.

The optional RMS™ remote monitoring system
allows comprehensive monitoring of system
parameters on a Windows®-based computer.

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

Exceptional fidelity and extended high­frequency performance

Constant-Q horn yields uniform
response throughout the coverage area

Extraordinarily flat amplitude and
phase response for tonal accuracy

Wide horn coverage available for larger,
wider rooms with the Acheron 100

Narrow, focused coverage available for
smaller rooms with the Acheron 80

Seamless integration with the
Acheron LF loudspeaker and HMS-10
surround loudspeaker

ApplicationsFeatures & Benefits

Small to medium-sized theatres

Larger theatres with use of Acheron LF

Re-recording stages

Production and postproduction studios

Acheron LCR System with Acheron LF

Network

Remote Monitor System

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Meyer Sound, Berkeley, CA, USA

THIS PRODUCT MUST BE GROUNDED

WARNINGS:

clearance from this surface and adequate ventilation.
To reduce the risk of electric shock do not remove cover.

To reduce the risk of fire or electric shock

Refer servicing to qualified personnel.

No operator or serviceable parts inside.

do not expose this appliance to rain or moisture.

To ensure proper operation, allow at least 6 inches

ACHTUNG:

ATTENTION:

UND REPARATUR NUR DURCH ELEKTROFÃCHKRAFTE

INTERNES NE SONT AUTORISEES QU'AU

AUTHORIZADO A PERSONAL TÉCNICO CALIFICO

ATENCIÓN:

This surface may reach high tempuratures white in use.

Auto-Voltage Select
95-125V ~ 208-235V~

1400W RMS MAX 1400W RMS MAX

50-60Hz 50-60Hz

U.K. WARNING:

REFER SERVICING TO QUALIFIED PERSONNEL.

NO OPERATOR SERVICEABLE PARTS INSIDE.

Turn on 165V~ Turn off 264V~

Turn on 85V~ Turn off 134V~

Operational Voltage Range:

PERSONNEL TECHNIQUE QUALIFIÉ

THIS APPARATUS MUST BE EARTHED.

ENTRETIENET REPARATIONS

GEHÃUSE NICHT OFFENE WARTUNG

ACCESO INTERNO SOLO

To meet the SPL require­ments for large rooms, the
Acheron 80 and Acheron 100
can be daisy-chained with
the Acheron LF loudspeaker,
which has been carefully
designed so its frequency and
phase responses compliment
the Acheron.

The Acheron LF has the same
low end frequency response
as the Acheron (38 Hz) and
rolls off at 320 Hz to avoid
any interference in the cross­over region of the Acheron.
This coupling is optimized to
allow a single parametric filter
to achieve a flat frequency
response with approximately
10 dB more of headroom in
the low frequencies (depend­ing on the room acoustics and
loading conditions).

Right

Center

Left

Cinema Screen

Acheron 80

Acheron 80/100 Architect Specifications

The loudspeaker shall be a self-powered, full-range system; the
transducers shall consist of a 15-inch diameter cone driver and
4-inch diaphragm compression driver. Two horn options shall
be available: 80-degree horizontal by 50-degree vertical, and
100-degree horizontal by 50-degree vertical. The loudspeaker
system shall incorporate internal processing electronics and a
two-channel amplifier, one channel for each driver. Processing
functions shall include frequency and phase correction, signal
division, and protection for the low- and high-frequency
sections. The crossover point shall be 580 Hz.

Each amplifier channel shall be class AB/H with complementary
MOSFET output stages. Burst capability for the low-frequency
channel shall be 1125 watts total with a nominal 4-ohm
resistive load and 560 watts for the high-frequency channel
with a nominal 8-ohm resistive load. Total burst power shall
be 1685 watts (3370 watts peak). Distortion (THD, IM, TIM) shall
not exceed 0.02%. Performance specifications for a typical

production unit shall be as follows, measured at 1/3-octave
resolution: operating frequency range shall be 37 Hz to 18 kHz;
phase response shall be ±30° from 700 Hz to 17 kHz; maximum
peak SPL shall be 139 dB at 1 meter, free field.

The audio input shall be electronically balanced with a 10 kOhm
impedance and accept a nominal 10 dBV (3.2 V rms, 4.5 V peak)
signal. Connectors shall be XLR (A-3) type male and female. RF
filtering shall be provided, and CMRR shall be greater than 50 dB
from 50 Hz to 500 Hz.

The internal power supply shall perform automatic voltage
selection, EMI filtering, soft current turn-on, and surge
suppression. Power requirements shall be nominal 100 V, 110 V,
or 230 V AC line at 50 or 60 Hz. UL and CE operating voltage
ranges shall be 100 to 240 V AC. Maximum peak current draw
during burst shall be 6.4 A at 115 V AC, 3.2 A at 230 V AC, and

7.2 A at 100 V AC. Current inrush during soft turn-on shall not

Acheron 80 Horn

80-degree horizontal by
50-degree vertical coverage

Acheron 100 Horn

100-degree horizontal by
50-degree vertical coverage

Circuit

breakers

Limit LEDs

Power LED

Acheron Rear Panel

Audio input and

loop output

connectors

exceed 7 A at 115 V AC, 7 A at 230 V AC, and 10 A at 100 V AC.
AC power connectors shall be locking NEMA L6-20 male inlet or
IEC 309 male inlet.

The loudspeaker system shall include support for the optional
RMS remote monitoring system module.

All loudspeaker components shall be mounted in an acoustically
vented enclosure constructed of premium birch plywood with a
black textured finish. Dimensions shall be 31.00" wide x 35.00"
high x 20.50" deep (787 mm x 889 mm x 521 mm). Weight shall
be 173 lbs (78.47 kg). Optional bracket adapters shall allow
the Acheron to be fixed to floors, as well as on top of the
Acheron LF, with uptilt or downtilt

The loudspeaker shall be the Meyer Sound Acheron.

RMS user panel

(optional)

AC power

connector (NEMA

L6-20 shown)

Acheron LF Loudspeaker

31.00

[787mm]

20.50

[521mm]

36.18

[919mm]

9.90

[251mm]

20.00

[508mm]

Acheron LF

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 theatres. The self-powered
Acheron LF with dual 15-inch drivers
boosts the headroom on the LCR channels
be 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

Dimensions

ranges. As a result, the system can deliver
the necessary power to completely fill
a large theatre 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 136 dB maximum 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, back­vented drivers include 4-inch voice
coils and are housed in a tuned, vented
enclosure that shares the same rectangular
footprint as the Acheron.

31.00" w x 36.18" h x 20.50" d
(787 mm x 919 mm x 521 mm)

185 lbs (83.91 kg)

Weight

Enclosure

Mounting

Premium birch plywood
Low gloss, black textured

Finish

3/8" threaded points on side
corners for optional bracket
adapters, which allow the
Acheron LF to be mounted to
floors; The Acheron 100 and
Acheron 80 can be mounted
on top of the Acheron LF with
uptilt or downtilt

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 on a Windows-based
computer.

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.

Acheron LF Architect Specifications

The loudspeaker shall be a self-powered bass system. The
transducers shall consist of two 15-inch cone drivers (with
4-inch voice coils), each rated to handle 1200 AES* watts.

The loudspeaker shall incorporate internal processing electronics
and a two-channel amplifier. Each amplifier channel shall be
class AB/H with complementary MOSFET output stages. Burst
capability shall be 1125 watts total with a nominal 4-ohm
resistive load. Total burst power shall be 2250 watts (4500 watts
peak). Distortion (THD, IM, TIM) shall not exceed 0.02%. The
audio input shall be electronically balanced with a 10 kOhm
impedance and accept a nominal 10 dBV (3.2 V rms, 4.5 V
peak) signal. Connectors shall be XLR type male and female.
RF filtering shall be provided, and CMRR shall be greater than
50 dB (50 Hz – 500 Hz). Performance specifications for a typical

production unit shall be as follows, measured at 1/3-octave
resolution: operating frequency range shall be 37 Hz to 370 Hz;
phase response shall be ±30° from 60 Hz to 230 Hz; maximum
peak SPL shall be 136 dB at 1 meter, free field.

The internal power supply shall perform automatic voltage
selection, EMI filtering, soft current turn-on, and surge
suppression. Power requirements shall be nominal 100 V, 110 V,
or 230 V AC line at 50 or 60 Hz. UL and CE operating voltage
range shall be 100 to 240 V AC. Maximum peak current draw
during burst shall be 19.0 A at 115 V AC, 9.5 A at 230 V AC, and

22.0 A at 100 V AC. Current inrush during soft turn-on shall not
exceed 7 A at 115 V AC, 7 A at 230 V AC, and 10 A and 100 V AC.
AC power connectors shall be locking NEMA L6-20 male inlet or
IEC 309 male inlet.

The loudspeaker system shall include support for the optional
RMS remote monitoring system module.

All loudspeaker components shall be mounted in an acoustically
vented enclosure constructed of premium birch plywood with a
black textured finish. Dimensions shall be 31.00" wide x 36.18"
high x 20.50" deep (787 mm x 919 mm x 521 mm). Weight shall
be 185 lbs (83.91 kg). Optional bracket adapters shall allow the
Acheron LF to be fixed to floors.

The loudspeaker shall be the Meyer Sound Acheron LF.

*Driven continuously for two hours with a band-limited noise
signal having a 6 dB peak-average ratio.

Acheron Specifications

Acoustical Acheron 80/100 Acheron LF

Operating Frequency Range

Frequency Response

Phase Response

Maximum Peak SPL

Dynamic Range

1

37 Hz – 18 kHz

2

38 Hz – 17 kHz ±4 dB
700 Hz – 17 kHz ±30°

3

139 dB
>110 dB

37 Hz – 370 Hz
38 Hz – 340 Hz ±4 dB
60 Hz – 230 Hz ±30°

4

136 dB
>110 dB

Coverage

Crossover

Acheron 80:
80° horizontal x 50° vertical
Acheron 100:
100° horizontal x 50° vertical

5

580 Hz

N/A

200 Hz

6

Transducers

Low Frequency

High Frequency

One high-power 15" cone driver
with neodymium magnet
Nominal impedance: 4 Ω
Voice coil size: 4"
Power handling: 1200 W (AES)

One 4" compression driver
Nominal impedance: 8 Ω

Voice coil size: 4"

Diaphragm size: 4"
Exit size: 1.5"
Power handling: 250 W (AES)

7

Two high-power 15" cone drivers
with neodymium magnets
Nominal impedance: 4 Ω
Voice coil size: 4"

7

Power handling: 1200 W (AES)
N/A

Audio Input

Differential, electronically balanced

Type

Maximum Common Mode Range

Connectors

Input Impedance

DC Blocking

RF Filter

Nominal Input Sensitivity

TIM Filter

Input Level

±15 V DC, clamped to earth for voltage transient protection
Female XLR input with male XLR loop output
10 kΩ differential between pins 2 and 3
Pin 1: Chassis/earth through 220 kΩ, 1000 pF, 15 V clamp network to

Wiring

provide virtual ground lift at audio frequencies
Pin 2: Signal +
Pin 3: Signal –
Case: Earth ground and chassis
None on input, DC blocked through signal processing
>50 dB, typically 80 dB (50 Hz – 500 Hz)

CMRR

Common mode: 425 kHz; Differential mode: 142 kHz
Integral to signal processing (<80 kHz)
10 dBV (3.2 V rms, 4.5 V peak) continuous is typically the onset of
limiting for noise and music
Audio source must be capable of producing +20 dBV (10 V rms,
14 V peak) into 600 Ω to produce the maximum peak SPL over the
operating bandwidth of the loudspeaker

Amplifier

Type

Output Power

Total Output
THD, IM, TIM

Load Capacity

Cooling

Complementary MOSFET
output stages (class AB/H)

8

1685 W
1125 W low channel
560 W high channel
3370 W peak
<.02%
4 Ω low channel
8 Ω high channel
Forced air cooling, two
internal fans (one ultra low­speed fan, one reserve fan)

Complementary MOSFET
output stages (class AB/H)
2250 W
1125 low channels

4500 W peak
<.02%
4 Ω low channels

Forced air cooling, two
internal fans (one ultra low­speed fan, one reserve fan)

AC Power

Safety Agency Rated Operating Range

Max. Long-Term Continuous Current (>10 sec)

Max. Long-Term Continuous Current (>10 sec)

Automatic Voltage Selection

Turn-on and Turn-off Points

Ultimate Short-Term Peak Current

Ultimate Short-Term Peak Current

Burst Current (<1 sec)

Burst Current (<1 sec)

Connector

Current Draw:

Idle Current

Inrush Current

Current Draw:

Idle Current

Inrush Current

250 V NEMA L6-20 (twistlock) inlet or IEC 309 male inlet
Automatic, two ranges, each with high-low voltage tap (uninterrupted)
95–125 V AC; 208–235 V AC, 50/60 Hz
85–134 V AC; 165–264 V AC

Acheron 80/100

0.71 A rms (115 V AC); 0.38 A rms (230 V AC); 0.79 A rms (100 V AC)

5.8 A rms (115 V AC); 2.8 A rms (230 V AC); 6.3 A rms (100 V AC)

9

6.4 A rms (115 V AC), 3.2 A rms (230 V AC), 7.2 A rms (100 V AC)
26 A peak (115 V AC), 14 A peak (230 V AC), 28 A peak (100 V AC)
7 A peak (115 V AC), 7 A peak (230 V AC), 10 A peak (100 V AC)

Acheron LF

0.64 A rms (115 V AC); 0.32 A rms (230 V AC); 0.85 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)

9

19.0 A rms (115 V AC), 9.5 A rms (230 V AC), 22.0 A rms (100 V AC)
39 A peak (115 V AC), 20 A peak (230 V AC), 45 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)

Equipped with two-conductor twisted-pair network, reporting all
operating parameters of amplifiers to system operator’s host computer

Notes:

1. Recommended maximum operating
frequency range. Response depends
on loading conditions and room
acoustics.

2. Measured free field with 1/3-octave
frequency resolution at 4 meters.

3. Measured free field with music
referred to 1 meter.

4. SPL for the Acheron LF calibrated to
complement the Acheron 80/100 in
the common frequency range.

5. At this frequency, the transducers for
the Acheron 80/100 produce equal
sound pressure levels.

6. Below this frequency, both
Acheron LF transducers are active.
Above this frequency, one transducer
rolls off to avoid interaction in the
higher frequencies (shorter wave-

7

lengths) of the Acheron 80/100.

7. Power handling measured using
AES standards: transducers driven
continuously for two hours with a
band-limited noise signal having a
6 dB peak-average ratio.

8. Amplifier wattage rating based on
the maximum unclipped burst sine­wave RMS voltage the amplifier
will produce into the nominal load
impedance: low frequency channel,
67 V rms (95 V peak) into 4 ohms; high
frequency channel, 67 V rms (95 V
peak) into 8 ohms.

9. AC power cabling must be of
sufficient gauge so that under
burst current rms conditions, cable
transmission losses do not drop
below the loudspeaker's specified
operating voltage range.

Acheron — 04.188.004.01 D

Copyright © 2010
Meyer Sound Laboratories Inc.
All rights reserved

meyer sound laboratories inc.

2832 San Pablo Avenue
Berkeley, CA 94702

T: +1 510 486.1166
F: +1 510 486.8356

[e-mail]
www.meyersound.com