Meyer Sound 100, LF, 80 User Manual

OPERATING INSTRUCTIONS

Acheron® Screen Channel Loudspeakers

Acheron 100, Acheron 80, and Acheron LF

Keep these important operating instructions.

Check www.meyersound.com for updates.

DECLARATION OF CONFORMITY ACCORDING TO ISO/IEC GUIDE 22 AND EN 45014

Manufacturer’s Name: Meyer Sound Laboratories Inc.

Manufacturer’s Address: 2832 San Pablo Avenue

Berkeley, CA 94702-2204, USA

Declares that the product:

Product Names: Acheron 80 Screen Channel Loudspeaker System

Acheron 100 Screen Channel Loudspeaker System
Acheron LF Screen Channel Loudspeaker System

Product Options: All

Conforms to the following Product Specifications:

Safety: EN 60065:2002

EMC: EN55103-1: 1997 emission

EN55103-2: 1997 immunity

This device also complies with EN 55103-1 & -2. Operation is subject to the following two conditions:

(1) this device may not cause harmful interference, and
(2) this device must accept any interference received, including interference
that may cause undesired operation.

Supplementary Information: The product herewith complies with the requirements of the Low Voltage

Directive (LVD) 2006/95/EC and the EMC Directive 2004/108/EC.

Signature:

1

2

Ms. Margie Garza
Director of Quality
Meyer Sound Laboratories Inc.
Berkeley, California 94702 USA
Issued October 27, 2008

European Contact:
Your local Meyer Sound dealer or
Meyer Sound Germany, GmbH.

© 2009, 2010
Meyer Sound. All rights reserved.
Acheron Operating Instructions, PN 05.188.005.01 B

The contents of this manual are furnished for informational purposes only, are subject to change without notice, and should not be con­strued as a commitment by Meyer Sound Laboratories Inc. Meyer Sound assumes no responsibility or liability for any errors or inaccura­cies that may appear in this manual. Except as permitted by applicable copyright law, no part of this publication may be reproduced,
stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, recording or otherwise, without prior writ­ten permission from Meyer Sound.

EXP, Intelligent AC, MAPP Online Pro, RMS, QuietCool, and all alpha-numeric designations for Meyer Sound products and accessories are
trademarks of Meyer Sound. Acheron, Compass, Galileo, Meyer Sound, the Meyer Sound wave logo, and SIM are registered trademarks
of Meyer Sound Laboratories Inc. (Reg. U.S. Pat. & Tm. Off.). All third-party trademarks mentioned herein are the property of their respec­tive trademark holders.

ii

SYMBOLS USED

!

!

!

These symbols indicate important safety or operating features in this booklet and on the chassis:

Dangerous voltages: risk of

electric shock

Pour indiquer les risques

résultant de tensions dangereuses

Warnung vor gef

elektrischer Spannung

Para indicar voltajes peligrosos Instrucciones importantes de

ährlicher

Important operating instructions Frame or chassis Protective earth ground

Pour indequer important

instructions

Wichtige Betriebsanweisung oder

Gebrauchsanleitung

funcionamiento y/o manteniento

IMPORTANT SAFETY INSTRUCTIONS

1. Read these instructions.

2. Keep these instructions.

3. Heed all warnings.

4. Follow all instructions.

5. Do not use this loudspeaker near water.

6. Clean only with dry cloth.

7. Do not block any ventilation openings. Install in accor­dance with Meyer Sound’s installation instructions.

8. Do not install near any heat sources such as radiators,
heat registers, stoves, or other apparatus that produce
heat.

9. Do not defeat the safety purpose of the grounding-type
plug. A grounding type plug has two blades and a third
grounding prong. The third prong is provided for your
safety. If the provided plug does not fit into your outlet,
consult an electrician for replacement of the obsolete
outlet.

10.Protect the power cord from being walked on or pinched,
particularly at plugs, convenience receptacles, and the
point where they exit from the loudspeaker. The AC
mains plug or appliance coupler shall remain readily
accessible for operation.

Masse, châssis Terre de protection

Rahmen oder Geh

Armadura o chassis Tierra proteccionista

äuse

Masse Schutzleiter

11.Only use attachments/accessories specified by Meyer
Sound.

12.Use only with the caster rails or rigging specified by
Meyer Sound, or sold with the loudspeaker. Handles are
for carrying only.

CAUTION: Rigging should only be done by

experienced professionals.

13.Unplug this loudspeaker during lightning storms or when
unused for long periods of time.

14.Disconnect the mains plug before disconnecting the
power cord from the loudspeaker.

15.Refer all servicing to qualified service personnel. Servic­ing is required when the loudspeaker has been damaged
in any way, such as when the power-supply cord or plug
has been damaged; liquid has been spilled or objects
have fallen into the loudspeaker; rain or moisture has
entered the loudspeaker; the loudspeaker has been
dropped; or when for undetermined reasons the loud­speaker does not operate normally.

CAUTION: To reduce the risk of electric shock,

do not expose this loudspeaker to rain or mois­ture. Do not install the loudspeaker in wet or humid
locations without using weather protection equip­ment from Meyer Sound.

iii

SAFETY SUMMARY

English

 To reduce the risk of electric shock, dis-

connect the loudspeaker from the AC
mains before installing audio cable.
Reconnect the power cord only after
making all signal connections.

 Connect the loudspeaker to a two-pole,

three-wire grounding mains receptacle.
The receptacle must be connected to a
fuse or circuit breaker. Connection to
any other type of receptacle poses a
shock hazard and may violate local
electrical codes.

 Do not install the loudspeaker in wet or

humid locations without using weather
protection equipment from Meyer
Sound.

 Do not allow water or any foreign object

to get inside the loudspeaker. Do not
put objects containing liquid on or near
the unit.

 To reduce the risk of overheating the

loudspeaker, avoid exposing it to direct
sunlight. Do not install the unit near
heat-emitting appliances, such as a
room heater or stove.

 This loudspeaker contains potentially

hazardous voltages. Do not attempt to
disassemble the unit. The unit contains
no user-serviceable parts. Repairs
should be performed only by factory­trained service personnel.

Français

 Pour réduire le risque d’électrocution,

débrancher la prise principale de l’haut­parleur, avant d’installer le câble d’inter­face allant à l’audio. Ne rebrancher le
bloc d’alimentation qu’après avoir
effectué toutes les connections.

 Branchez l’haut-parleur dans une prise

de courant à 3 dérivations (deux pôles
et la terre). Cette prise doit être munie
d’une protection adéquate (fusible ou
coupe-circuit). Le branchement dans
tout autre genre de prise pourrait
entraîner un risque d’électrocution et
peut constituer une infraction à la régle­mentation locale concernant les instal­lations électriques.

 Ne pas installer l’haut-parleur dans un

endroit où il y a de l’eau ou une humid­ité excessive.

 Ne pas laisser de l’eau ou tout objet

pénétrer dans l’haut-parleur. Ne pas
placer de r´cipients contenant un liquide
sur cet appareil, ni à proximité de celui­ci.

 Pour éviter une surchauffe de l’haut-

parleur, conserver-la à l’abri du soleil.
Ne pas installer à proximité d’appareils
dégageant de la chaleur tels que radia­teurs ou appareils de chauffage.

 Ce haut-parleur contient des circuits

haute tension présentant un danger. Ne
jamais essayer de le démonter. Il n’y a
aucun composant qui puisse être
réparé par l’utilisateur. Toutes les répa­rations doivent être effectuées par du
personnel qualifié et agréé par le con­structeur.

Deutsch

 Um die Gefahr eines elektrischen

Schlages auf ein Minimum zu
reduzieren, den Lautsprecher vom
Stromnetz trennen, bevor ggf. ein
Audio-Schnittstellensignalkabel ange­schlossen wird. Das Netzkabel erst
nach Herstellung aller Signalverbindun­gen wieder einstecken.

 Der Lautsprecher an eine geerdete

zweipolige Dreiphasen-Netzsteckdose
anschließen. Die Steckdose muß mit
einem geeigneten Abzweigschutz
(Sicherung oder Leistungsschalter) ver­bunden sein. Der Anschluß der unter­brechungsfreien Stromversorgung an
einen anderen Steckdosentyp kann zu
Stromschlägen führen und gegen die
örtlichen Vorschriften verstoßen.

 Der Lautsprecher nicht an einem Ort

aufstellen, an dem sie mit Wasser oder
übermäßig hoher Luftfeuchtigkeit in
Berührung kommen könnte.

 Darauf achten, daß weder Wasser noch

Fremdkörper in das Innere den
Lautsprecher eindringen. Keine
Objekte, die Flüssigkeit enthalten, auf
oder neben die unterbrechungsfreie
Stromversorgung stellen.

 Um ein Überhitzen dem Lautsprecher

zu verhindern, das Gerät vor direkter
Sonneneinstrahlung fernhalten und
nicht in der Nähe von wärmeabstrahl­enden

 Haushaltsgeräten (z.B. Heizgerät oder

Herd) aufstellen.

 Im Inneren diesem Lautsprecher herr-

schen potentiell gefährliche Spannun­gen. Nicht versuchen, das Gerät zu
öffnen. Es enthält keine vom Benutzer
reparierbaren Teile. Reparaturen dürfen
nur von ausgebildetem Kundenienst­personal durchgeführt werden.

Español

 Para reducir el riesgo de descarga eléc-

trica, desconecte de la red de voltaje el
altoparlante antes de instalar el cable
de señal de audio. Vuelva a conectar la
alimentacion de voltaje una vez efectu­adas todas las interconexiones de
señalizacion de audio.

 Conecte el altoparlante a un tomacorri-

ente bipolar y trifilar con neutro de
puesta a tierra. El tomacorriente debe
estar conectado a la protección de deri­vación apropiada (ya sea un fusible o un
disyuntor). La conexión a cualquier otro
tipo de tomacorriente puede constituir
peligro de descarga eléctrica y violar los
códigos eléctricos locales.

 No instale el altoparlante en lugares

donde haya agua o humedad excesiva.

 No deje que en el altoparlante entre

agua ni ningún objeto extraño. No
ponga objetos con líquidos encima de
la unidad ni cerca de ella.

 Para reducir el riesgo de sobrecalen-

tamiento, no exponga la unidad a los
rayos directos del sol ni la instale cerca
de artefactos que emiten calor, como
estufas o cocinas.

 Este altoparlante contiene niveles de

voltaje peligrosos en potencia. No
intente desarmar la unidad, pues no
contiene piezas que puedan ser repar­das por el usuario. Las reparaciones
deben efectuarse únicamente por parte
del personal de mantenimiento capaci­tado en la fábrica.

iv

CONTENTS

Chapter 1: Introduction 7

How to Use This Manual 7
Acheron Screen Channel Loudspeaker 7

Chapter 2: Power Requirements 11

AC Connector 11
AC Power Distribution 12
Acheron Voltage Requirements 12
Acheron Current Requirements 12
Powering Up the Acheron 13
Electrical Safety Guidelines 13

Chapter 3: Amplification and Audio 15

Audio Connectors 15
Limiting 16
Amplifier Cooling System 17

Chapter 4: Integrating Acheron LF Loudspeakers 19

Integrating Acheron LF Loudspeakers 19
Galileo Loudspeaker Management System 20
Using Digital Signal Processors and Crossovers with Acheron Systems 20

Chapter 5: Mounting 21

Acheron Floor Mount Brackets 21
Acheron Stacking Bracket 24

Chapter 6: The RMS Remote Monitoring System 29

RMS Software 29
RMS Module 30
Resetting the RMS Module 31

Chapter 7: System Design and Integration Tools 33

MAPP Online Cinema 33
SIM 3 Measurement System 34

Appendix A: Acheron 80 and Acheron 100 Specifications 35

Appendix B: Acheron LF Specifications 39

v

CONTENTS

vi

CHAPTER 1: INTRODUCTION

!

HOW TO USE THIS MANUAL

Make sure to read these operating instructions in their

®

entirety before configuring a system with Acheron
speakers. In particular, pay close attention to material
related to safety issues.

As you read these operating instructions, you will encounter
the following icons for notes, tips, and cautions:

NOTE: A note identifies an important or useful

piece of information relating to the topic under

discussion.

TIP: A tip offers a helpful tip relevant to the topic

at hand.

CAUTION: A caution gives notice that an

action may have serious consequences and
could cause harm to equipment or personnel, or
could cause delays or other problems.

Information and specifications are subject to change.
Updates and supplementary information are available at

www.meyersound.com

.

loud-

ACHERON SCREEN CHANNEL LOUDSPEAKER

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 two-way 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.

Meyer Sound Technical Support is available at:

■ Te l: +1 510 486.1166

■ Te l: +1 510 486.0657 (after hours support)

■ Web: www.meyersound.com/support

■ Email: [e-mail]

Acheron 100 Screen Channel Loudspeaker

The Acheron loudspeaker is available in two full-range mod­els: the Acheron 100, with a 100-degree horizontal by 50­degree 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 narrow theatres and re­recording, production, and post-production facilities.

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 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.

7

CHAPTER 1: INTRODUCTION

Boasting a frequency response of 38 Hz to 17 kHz at ±4 dB,
as well as a generous peak output of 139 dB at 1 meter 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 post-production facilities. When pairing
an Acheron with an Acheron LF, the system offers enough
headroom for large theatres.

Strategically placed 3/8-inch threaded points on the side
corners of the Acheron cabinet allow the unit to be secured
to floors with uptilt or downtilt using the optional mounting
brackets. The Acheron can also be mounted on top of the
Acheron LF loudspeaker, with uptilt or downtilt, using the
optional stacking brackets. Both brackets are available for
purchase from Meyer Sound.

Acheron 80 Screen Channel Loudspeaker

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.

Acheron 100 with Optional Floor Mount Brackets, Front View

Acheron 100 with Optional Floor Mount Brackets, Rear View

-

8

ACHERON OPERATING INSTRUCTIONS

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 the­atres. The self-powered Acheron LF with dual 15-inch driv­ers boosts the headroom on the LCR channels by
converting each Acheron loudspeaker to a system with
three low-frequency drivers in an aligned column.

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 Windows­based computer.

Acheron LF Screen Channel Loudspeaker

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 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
(at 1 meter) were carefully chosen to compliment the
Acheron. The Acheron LF also features the same high­power 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.

Acheron LF with Acheron 80

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

9

CHAPTER 1: INTRODUCTION

10

CHAPTER 2: POWER REQUIREMENTS

Ground
(green/yellow)

Neutral
(blue)

Line (brown)

Ground
(green/yellow)

X-neutral
(blue)

Y-li ne (b row n)

Blue = neutral

Brown = hot

Yell ow /gr e en =
earth ground
(chassis

!

The Acheron loudspeaker combines advanced loudspeaker
technology with equally advanced power capabilities.
Understanding power distribution, voltage and current
requirements, and electrical safety guidelines is critical to
the safe operation of the Acheron.

AC CONNECTOR

The Acheron AC connector supplies AC power to the unit
and is located on its rear user panel. The Acheron can be
equipped with one of the following AC connectors:

■ IEC 309 male inlet connector.

AC Power Cable with Edison Adapter

The Acheron can be powered from a standard three-prong
Edison outlet with an L6-20 to Edison adapter (available for
purchase from Meyer Sound; PN 27.033.024.03).

L6-20 to Edison AC Power Cable Adapter

AC Connector Wiring

When wiring international or special-purpose AC power
cables and connectors, use the following wiring scheme:

■ NEMA L6-20 (twistlock) male inlet

The Acheron requires a grounded outlet. To operate safely
and effectively, it is extremely important that the entire sys­tem be properly grounded.

If you replace the included AC power cable, make sure to
use a cable that is wired correctly and equipped with the
with the appropriate power plug (on the other end) for the
area in which you will operate the unit.

AC Cable Wiring Scheme

■ Connect the blue wire to the black terminal, or the termi-

nal marked with an N.

■ Connect the brown wire to the red terminal, or the termi-

nal marked with an L.

■ Connect the yellow and green wire to the green (or green

and yellow) terminal, or the terminal marked with an E.

CAUTION: When creating AC power cables

and distribution systems, it is important to pre­serve AC line polarity and connect the earth ground
on both ends of the cable. The Acheron requires a
grounded connection. Always use a grounded outlet
and plug. It is extremely important that the system be
properly grounded to operate safely and properly. Do
not ground-lift the AC cable.

11

CHAPTER 2: POWER REQUIREMENTS

!

Line 1

Line 2 Line 3

Neutral

Earth Ground

!

AC POWER DISTRIBUTION

All components in an audio system (self-powered loud­speakers, processors, etc.) must be properly connected to
an AC power distribution system, to ensure that AC line
polarity is preserved and that all grounding points are con­nected to a single node or common point using the same
cable gauge as the neutral and line cables.

NOTE: Improper grounding of connections

between loudspeakers and the rest of the
audio system may produce noise or hum, or cause
serious damage to the input and output stages of the
system’s electronic components.

CAUTION: Before applying AC power to any

Meyer Sound self-powered loudspeaker, make
sure that the voltage potential difference between the
neutral and earth-ground lines is less than 5 V AC.

Figure 1 illustrates a basic three-phase AC distribution sys­tem with the loudspeaker load distributed across the three
phases. All loudspeakers are connected to common neutral
and earth-ground lines.

ACHERON VOLTAGE REQUIREMENTS

The Acheron operates safely and continuously when the AC
voltage stays within 85–134 V AC and 165–264 V AC at 50
or 60 Hz. The loudspeaker allows any combination of volt­age to GND (neutral-line-ground or line-line-ground).

If the voltage drops below 85 V (brownout), the Acheron
uses stored power to continue operating temporarily; the
loudspeaker will shut down if the voltage does not rise
above the low boundary before the stored power is used.

If the voltage rises above 275 V, the power supply could
become damaged.

CAUTION: The power source for the Acheron

should always operate within the required volt­age range, at least a few volts from the upper and
lower ranges. This ensures that AC voltage variations
from the service entry — or peak voltage drops due
to cable runs — will not cause the loudspeaker’s
amplifier to cycle on and off or cause damage to the
power supply.

TIP: Since the Acheron does not require a dedi-

cated neutral line, and it can tolerate elevated
voltages from the ground line, it can be connected to
line-line terminals in 120 V, 3-phase Wye systems.
This results in 208 V AC between lines (nominal) and
therefore draws less current than when using 120 V
AC (line-neutral). Make sure that the voltage remains
within the Acheron’s recommended operating win­dows (85–134 V AC and 165–264 V AC). The ground
line must always be used for safety reasons and the
line-to-ground voltage should never exceed 250 V AC
(typically 120 V AC from line-to-ground).

Figure 1: AC Power Distribution System

12

ACHERON CURRENT REQUIREMENTS

The current draw for the Acheron is dynamic and fluctuates
as operating levels change. Since different cables and cir­cuit breakers heat up at varying rates, it is important to
understand the following types of current ratings and how
they affect circuit breaker and cable specifications.

■ Idle Current — The maximum rms current during idle

periods.

■ Maximum Long-Term Continuous Current — The

maximum rms current during a period of at least 10 sec­onds. The Maximum Long-Term Continuous Current is
used to calculate temperature increases for cables, to
ensure that cable sizes and gauges conform to electrical
code standards. The current rating is also used as a rat­ing for slow-reacting thermal breakers.

ACHERON OPERATING INSTRUCTIONS

!

!

Earth ground

Chassis ground

■ Burst Current — The maximum rms current during a

period of around one second. The Burst Current is used
as a rating for magnetic breakers. It is also used for cal­culating the peak voltage drop in long AC cable runs
according to the following formula:

V pk (drop) = I pk x R (cable total)

■ Ultimate Short-Term Peak Current — A rating for fast-

reacting magnetic breakers.

■ Inrush Current — The spike of initial current encoun-

tered when powering on.

You can use Table 1 and Table 2 as guidelines for selecting
cable gauges and circuit breaker ratings for the system’s
operating voltage.

Table 1: Acheron 100 and Acheron 80 Current Draw

Current Draw 115 V AC 230 V AC 100 V AC

Idle Current 0.71 A rms 0.38 A rms 0.79 A rms

Maximum Long-Term
Continuous Current

Burst Current 6.4 A rms 3.2 A rms 7.2 A rms

Ultimate Short-Term
Peak Current

Inrush Current 7 A peak 7 A peak 10 A peak

Table 2: Acheron LF Current Draw

Current Draw 115 V AC 230 V AC 100 V AC

Idle Current 0.64 A rms 0.32 A rms 0.85 A rms

Maximum Long-Term
Continuous Current

Burst Current 19 A rms 9.5 A rms 22 A rms

Ultimate Short-Term
Peak Current

Inrush Current 7 A peak 7 A peak 10 A peak

5.8 A rms 2.8 A rms 6.3 A rms

26 A peak 14 A peak 28 A peak

8.8 A rms 4.4 A rms 10.0 A rms

39 A peak 20 A peak 45 A peak

The minimum electrical service amperage required by an
Acheron loudspeaker system is the sum of the Maximum
Long-Term Continuous Current for each loudspeaker. An
additional 30 percent above the minimum amperage is rec­ommended to prevent peak voltage drops at the service
entry.

POWERING UP THE ACHERON

When AC power is applied to the Acheron its Intelligent AC™
power supply automatically selects the correct operating
voltage, allowing it to be used internationally without manu­ally setting voltage switches. In addition, Intelligent AC sup­presses high-voltage transients up to several kilovolts, filters
common mode and differential mode radio frequencies
(EMI), and sustains operation temporarily during low-voltage
periods.

When powering up the Acheron, the following startup events
take place over several seconds.

1. Audio output is muted.

2. Voltage is detected and the power supply mode is auto­matically adjusted as necessary.

3. The primary ultra low-noise fan turns on.

4. The power supply ramps up.

5. The green Active LED on the user panel lights up, indi­cating the loudspeaker is ready to output audio.

CAUTION: If the Active LED does not light up,

or the Acheron does not output audio after ten
seconds, remove AC power immediately and verify
that the voltage is within the required range. If the
problem persists, contact Meyer Sound Technical
Support.

CAUTION: If either of the loudspeaker’s circuit

breakers trip (the white center buttons disen­gage), make sure to disconnect the AC power cable
and wait one minute, to allow the stored power to
dissipate, before resetting the breakers. If necessary,
contact Meyer Sound for repair information.

ELECTRICAL SAFETY GUIDELINES

Pay close attention to these important electrical and safety
guidelines.

■ The Acheron requires a grounded outlet. Always use a

grounded outlet and plug.

NOTE: For best performance, the AC cable

voltage drop should not exceed 10 V, or
10 percent at 115 V and 5 percent at 230 V. Make
sure that even with AC voltage drops that the AC
voltage always remains within the operating win­dows.

13

CHAPTER 2: POWER REQUIREMENTS

■ Make sure the AC power cable for the loudspeaker has

the appropriate power plug (on the other end) for the
area in which you will operate the loudspeaker.

■ Do not operate the unit if the power cable is frayed or

broken.

■ Keep all liquids away from the Acheron to avoid hazards

from electrical shock.

14

CHAPTER 3: AMPLIFICATION AND AUDIO

The Acheron drivers are powered by a two-channel propri­etary Meyer Sound amplifier with MOSFET output stages. The
audio signal is processed with an electronic crossover, cor­rection filters for phase and frequency response, and driver
protection circuitry. Each channel has peak and rms limiters
that prevent driver over-excursion and regulate the tempera­ture of the voice coil.

The Acheron rear panel has an audio Input and Loop output
connector, Limit LEDs, and an optional RMS module for
connecting to the RMS remote monitoring system (see
Chapter 6, “The RMS Remote Monitoring System”).

AUDIO CONNECTORS

The Acheron and Acheron LF include female XLR Input and
male XLR Loop output connectors.

Pins 2 and 3 carry the input as a differential signal. Pin 1 is
connected to earth through a 220 kOhm, 1000 pF, 15 V
clamped network. This circuitry provides virtual ground lift
for audio frequencies while allowing unwanted signals to
bleed to ground. Make sure to use standard, balanced XLR
audio cables with all three pins connected on both ends.
Telescopic grounding is not recommended, and shorting an
input connector pin to the case may cause a ground loop,
resulting in hum.

TIP: If unwanted noise or hiss is produced by

the loudspeaker, disconnect its input cable. If
the noise stops, there is most likely nothing wrong
with the loudspeaker. To locate the source of the
noise, check the audio cable, source audio, and AC
power.

Loop Output Connector

The male XLR Loop output connector allows Acheron and
Acheron LF loudspeakers to be looped from a single audio
source. For applications that require multiple Acherons and
Acheron LFs, connect the Loop output of the first unit to the
Input of the second, and so forth.

Acheron Audio Connectors, Input and Loop Output

Input Connector

The female XLR Input connector accepts a balanced audio
signal with an input impedance of 10 kOhm. The connector
uses the following wiring:

■ Pin 1 — 220 kOhm to chassis and earth ground (ESD

clamped)

■ Pin 2 — Signal (+)

■ Pin 3 — Signal (–)

■ Case — Earth (AC) ground and chassis

NOTE: The order in which loudspeakers are

connected when looping audio signals is unim­portant. The Loop connector is wired in parallel to the
Input connector and transmits the unbuffered source
signal even when the Acheron is powered off.

To avoid distortion when looping multiple Acherons, make
sure the source device can drive the total load impedance of
the looped loudspeakers. In addition, the source device
must be capable of delivering approximately 20 dBV
(10 V rms into 600 ohms) to yield the maximum peak SPL
over the entire operating bandwidth of the loudspeakers.
Most professional audio equipment can transmit these
source levels.

To calculate the load impedance for the looped loudspeak­ers, divide 10 kOhms (the input impedance for a single
Acheron) by the number of looped loudspeakers. For exam­ple, the load impedance for 10 Acheron loudspeakers is
1000 ohms (10 kOhms / 10). To drive this number of looped
loudspeakers, the source device should have an output
impedance of 100 ohms or less. This same rule applies
when looping Acheron loudspeakers with other self-pow­ered Meyer Sound loudspeakers and subwoofers.

15

CHAPTER 3: AMPLIFICATION AND AUDIO

!

!

NOTE: Most source devices are capable of

driving loads no smaller than 10 times their

output impedance.

CAUTION: Make sure that all cabling for

looped loudspeakers is wired correctly (Pin 1
to Pin 1, Pin 2 to Pin 2, and so forth) to prevent the
polarity from being reversed. If one or more loud­speakers in a system have reversed polarity, fre­quency response and coverage will be significantly
degraded.

LIMITING

Acheron loudspeakers employ Meyer Sound’s advanced

®

TruPower
loudspeaker impedance and set the limiting threshold by
measuring voltage alone. This method is inaccurate
because loudspeaker impedances change as frequency
content in the source material changes, and as thermal val­ues for the loudspeaker’s voice coil and magnet vary. Con­sequently, conventional limiters often begin limiting
prematurely, which reduces system headroom and dynamic
range.

limiting. Conventional limiters assume a constant

Limiting LEDs

Behavior for the Acheron Limit LEDs is described below:

■ The low- and high-frequency drivers for the Acheron 80

and Acheron 100 are powered by separate amplifier
channels, each with their own limiter. Limiting activity is
indicated with a High Limit LED for the high-frequency
channel, and a Low Limit LED for the low-frequency
channel.

■ The two low-frequency drivers for the Acheron LF are

powered by separate amplifier channels that are routed
to a single limiter. When a safe power level is exceeded
in either channel, limiting is engaged for both channels
and the Low Limit LED lights.

When engaged, the limiters not only protect the drivers but
also prevent signal peaks from causing excessive distortion
in the amplifier channels, thereby preserving headroom and
maintaining smooth frequency responses at high levels.
When levels returns to normal, below the limiter thresholds,
limiting ceases.

The Acheron performs within its acoustical specifications at
normal temperatures when the Limit LEDs are unlit, or if the
LEDs are lit for two seconds or less and then turn off for at
least one second. If the LEDs remain lit for longer than three
seconds, the loudspeaker enters hard limiting where:

Acheron Limit LEDs

In contrast, TruPower limiting anticipates varying loud­speaker impedances by measuring both current and voltage
to compute the actual power dissipation in the voice coil.
This improves performance, both before and during limiting,
by allowing the driver to produce the maximum SPL across
its entire frequency range. TruPower limiting also eliminates
power compression at high levels over lengthy periods,
which helps regulate voice coil temperatures, thereby
extending the life of the driver.

NOTE: Since TruPower limiting only reduces

signal levels to keep voice coil temperatures

under a safe margin, signal peaks remain unaffected.

■ Increases to the input level have no effect.

■ Distortion increases due to clipping and nonlinear driver

operation.

■ The drivers are subjected to excessive heat and excur-

sion, which will compromise their life span and may
eventually lead to damage over time.

CAUTION: The Limit LEDs indicate when a

safe, optimum level is exceeded. If the
Acheron 80s or Acheron 100s in a system begin to
limit before reaching the required SPL, consider add­ing Acheron LFs to the system (see Chapter 4, “Inte­grating Acheron LF Loudspeakers”).

NOTE: Acheron loudspeakers use optical limit-

ers that add no noise and have no effect on the
signal when the limiters are not engaged and the
Limit LEDs are not lit.

16

ACHERON OPERATING INSTRUCTIONS

Heat sink/
amplifier

Air filter

Power
supply

Air
intake

Low­noise
fans

!

!

AMPLIFIER COOLING SYSTEM

The Acheron uses a forced-air cooling system with two fans
(one variable-speed, ultra low-noise primary fan and one
reserve fan) to prevent the amplifier module from overheat­ing. The fans draw air in through ducts on the front of the
cabinet, over the heat sink, and out the rear of the cabinet.
Because dust does not accumulate in the amplifier circuitry,
its life span is increased significantly.

Dust and the Amplifier Module

Operating the Acheron in dusty environments, or for pro­longed, intensive periods, may cause dust to accumulate
along its airflow path, thereby preventing normal cooling.
Under these circumstances, it may be necessary to periodi­cally remove the air intake foam and use compressed to air
to clear the dust from the foam and air ducts.

In addition, if the amplifier gets unusually hot, you should
remove the amplifier module and use compressed air to
clear any dust from its heat sink.

CAUTION: Make sure to unplug the AC power

from the Acheron before cleaning its amplifier.

CAUTION: To keep the Acheron from getting

too hot, allow for proper ventilation, 3–4

inches, behind the loudspeaker.

Airflow for the Acheron

When the Acheron heat sink temperature is below 42° C, the
variable-speed primary fan runs continuously at its slowest
speed with an inaudible operating noise. The primary fan
increases speed when the heat sink temperature reaches
42° C; the primary reaches full speed at 62° C and is barely
audible near the cabinet, even without an audio signal. If the
the heat sink temperature reaches 74° C, the reserve fan
turns on. The reserve fan turns on if:

■ The primary fan has failed (check status immediately)

■ High source levels are encountered for extended periods

■ Dust has accumulated along the cooling path

The reserve fan turns off when the heat sink temperature
lowers to 68° C.

NOTE: In the unlikely event that the reserve fan

does not keep the Acheron heat sink tempera­ture below 85° C, the unit automatically shuts down
until AC power is removed and reapplied. If the
Acheron shuts down again after cooling and re­applying AC power, contact Meyer Sound for repair
information.

17

CHAPTER 3: AMPLIFICATION AND AUDIO

18

CHAPTER 4: INTEGRATING ACHERON LF LOUDSPEAKERS

Low frequency

Low frequency

Low frequency

High frequency

Acheron LF

Acheron 100

Screen

Right

Center

Left

!

INTEGRATING ACHERON LF LOUDSPEAKERS

To meet the SPL and low frequency headroom requirements
of large rooms, the Acheron 100 or Acheron 80 can be
daisy-chained with the Acheron LF loudspeaker, creating a
system with three low frequency drivers and one high fre­quency driver. Adding an Acheron LF yields approximately a
10 dB boost in the low frequency range, depending on load­ing conditions and room acoustics.

The Acheron LF 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.

■ At 38 Hz to 150 Hz, all three low frequency drivers are

active. At 150 Hz, the bottom Acheron LF low frequency
driver rolls off.

■ At 150 Hz to 300 Hz, two low frequency drivers are

active: the top Acheron LF driver and the Acheron low
frequency driver. At 300 Hz, the top Acheron LF low fre­quency driver rolls off.

■ At 300 Hz to 580 Hz, only the Acheron low frequency

driver is active, which enables a smooth crossover to the
high frequency driver.

This 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 internal 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 theatre.

Acheron 100 with Acheron LF

Acheron LCR System with Acheron LFs

Achieving a Flat Frequency Response with an
Acheron / Acheron

When the Acheron and Acheron LF are daisy-chained (using
the Loop output connector on the user panel) an approxi­mate boost of 10 dB at 110 Hz results, depending on the
loading conditions and room acoustics. To achieve a flat fre­quency response in this configuration, a single parametric
filter with the following characteristics can be applied to the
signal:

Filter type Parametric

Frequency 110 Hz

Bandwidth 2 (Q = 0.6667)

Amplitude –10 dB

CAUTION: When daisy-chaining Acherons and

Acheron LFs, make sure the audio cables are

wired correctly to avoid polarity reversals.

LF Stack

19

CHAPTER 4: INTEGRATING ACHERON LF LOUDSPEAKERS

GALILEO LOUDSPEAKER MANAGEMENT SYSTEM

The Galileo® loudspeaker management system was
designed by Meyer Sound as a comprehensive solution for
driving and aligning loudspeakers, especially those com­prised of its self-powered loudspeakers. A range of Galileo
systems are available, depending on the needs of system,
with each including hardware processors with low-latency
outputs and processing that includes gain, polarity, delay,
low- and high-pass filters, and equalization (parametric and
TruShaping). The Galileo processors can be controlled from
the extensive Compass™ software running on a Windows or

®

Mac

computer. The Galileo system also interfaces seam-

®

lessly with Meyer Sound’s SIM

3 audio analyzer.

USING DIGITAL SIGNAL PROCESSORS AND CROSSOVERS WITH ACHERON SYSTEMS

Full-range signals can be connected directly to Meyer
Sound self-powered loudspeakers because they have built­in active crossovers. External crossovers and digital signal
processors are optional and should be used with caution as
they can introduce phase shifts that cause destructive can­cellations.

If a digital signal processor is used to drive an Acheron LCR
system, the Acherons and Acheron LFs should be driven
from the same processor to keep their delay times the same.
Otherwise a phase shift between the loudspeakers may be
encountered. In addition, you should verify the delay time
between channels: some digital signal processors may incur
channel-to-channel delays when the processor is near max­imum throughput, which becomes more likely as the number
of filters in use by the processor is increased.

In no case should a filter higher than the 2nd order be used
on source signals. The additional phase shift introduced by
these filters deteriorates the impulse response, and the
higher roll-off does not improve crossover interaction.

If loudspeakers will be driven directly from a digital signal
processor, make sure the signal is sufficient to drive the total
load impedance of the connected loudspeakers (see “Loop
Output Connector” on page 15).

TIP: To address the collective concerns of sys-

tem design verification, subwoofer integration,
digital signal processors, delay systems, and acousti­cal conditions, a measurement system like Meyer
Sound’s SIM 3 is strongly recommended.

20

CHAPTER 5: MOUNTING

!

Strategically placed 3/8-inch threaded points on the side
corners of the Acheron cabinet allow the unit to be secured
to floors with uptilt or downtilt using the optional mounting
brackets. The Acheron can also be mounted on top of the
Acheron LF loudspeaker, also with uptilt or downtilt, using
the optional stacking brackets. Both brackets are available
for purchase from Meyer Sound.

Important Safety Considerations!

When installing Meyer Sound loudspeakers and subwoof­ers, the following precautions should always be observed:

■ All Meyer Sound products must be used in accordance

with local, state, federal, and industry regulations. It is
the owner’s and user’s responsibility to evaluate the reli­ability of any mounting and rigging method for their
application. Mounting and rigging should only be carried
out by experienced professionals.

■ Use mounting and rigging hardware that has been rated

to meet or exceed the weight being hung.

■ Make sure to attach mounting hardware to the building's

structural components (studs or joists), and not just to
the wall surface. Verify that the building's structure and
the anchors used for the installation will safely support
the total weight of the mounted loudspeakers.

ACHERON FLOOR MOUNT BRACKETS

The Acheron floor mount brackets secure Acheron loud­speakers to floors with downtilt and uptilt angles of
0–18 degrees (in 3-degree increments). The floor mount
brackets should also be used with Acheron LF loudspeakers
when stacking an Acheron on top of the Acheron LF.

Acheron Floor Mount Brackets

■ Use mounting hardware appropriate for the surface

where the loudspeaker will be installed.

■ Make sure bolts and eyebolts are tightened securely.

®

Meyer Sound recommends using Loctite

on eyebolt

threads and safety cables.

■ Inspect mounting and rigging hardware regularly. Imme-

diately replace any worn or damaged components.

Acheron and Acheron LF Side Screws

The Acheron and Acheron LF ship with four 3/8-16 x 1.5­inch screws installed on each loudspeaker side (eight total).
These screws and threaded points are used to secure the
floor mount and stacking brackets to the loudspeakers.

CAUTION: If the Acheron side screws are

removed to install the brackets, make sure to
always reinstall the screws, and tighten them
securely. If the side screws are not present when
using the loudspeakers, air leakage will result, which
will adversely affect frequency response.

Acheron with Floor Mount Brackets

Acheron Floor Mount Bracket Kit Contents

The Acheron floor mount kit (PN 40.188.026.01) includes the
following parts.

Part Part number Quantity

Acheron floor mount bracket (left) 64.188.042.01 1

Acheron floor mount bracket (right) 64.188.043.01 1

Flat washers 113.509 4

NOTE: The 3/8-16 x 1.5-inch screws required

for securing the floor mount brackets to the
Acheron are shipped with the loudspeaker installed in
the two bottom screw holes on each side (four total).

21

CHAPTER 5: MOUNTING

Front

–3°

!

Floor Mounting Acherons and Acheron LFs

To floor mount an Acheron or Acheron LF:

1. Remove the two 3/8-16 x 1.5-inch screws at the bottom
of each loudspeaker side (four total).

2. Secure the left bracket to the left side of the loudspeaker
with two of the removed screws and two of the included
flat washers.

Floor Mounting Acherons with Downtilt and Uptilt

The Acheron floor mount brackets can mount loudspeakers
with downtilt or uptilt. Available angles are 3-18 degrees in
3-degree increments. The direction in which the brackets are
oriented determines whether the loudspeaker can be
mounted with downtilt or uptilt.

■ To mount the loudspeaker at 0 degrees with no downtilt

or uptilt, use the bottom bracket holes.

■ To mount the loudspeaker with downtilt, orient the

bracket with the large end toward the rear of the loud­speaker. For available downtilt angles, see “Floor Mount
Downtilt Angles” on page 23.

■ To mount the loudspeaker with uptilt, orient the bracket

with the large end toward the front of the loudspeaker.
For available uptilt angles, see “Floor Mount Uptilt
Angles” on page 23.

3. Repeat the previous step with the right bracket and the
remaining two screws and washers.

4. Secure the brackets to the floor with fasteners (not
included) appropriate for the floor surface.

Acheron Floor Mounted with 3-Degree Downtilt

CAUTION: When using the floor mount brack-

ets with an Acheron LF that will also have an
Acheron stacked on top of it, mount the Acheron LF
at 0 degrees using the bottom bracket holes.

22

ACHERON OPERATING INSTRUCTIONS

–18°
–15°
–12°

–9°
–6°
–3°

Attach here
for downtilt

–6°

–18°–12°

–3°

Front

+18°
+15°
+12°
+9°
+6°
+3°

Attach here
for uptilt

+6°

–18°+12°

+3°

Front

Floor Mount Downtilt Angles

When the floor mount brackets are oriented with the
bracket’s large end toward the rear of the loudspeaker, the
Acheron can be mounted with downtilt angles of
3-18 degrees in 3-degree increments.

Acheron Floor Mount Bracket Oriented for Downtilt

The small end of the bracket attaches to the loudspeaker
using the top hole. The large end of the bracket attaches to
the loudspeaker with one of the angled holes.

Floor Mount Uptilt Angles

When the floor mount brackets are oriented with the
bracket’s large end toward the front of the loudspeaker, the
Acheron can be mounted with uptilt angles of 3-18 degrees
in 3-degree increments.

Acheron Floor Mount Bracket Oriented for Uptilt

The small end of the bracket attaches to the loudspeaker
using the top hole. The large end of the bracket attaches to
the loudspeaker with one of the angled holes.

Acheron Floor Mount Downtilt Angles

Acheron Floor Mount Uptilt Angles

23

CHAPTER 5: MOUNTING

!

1” x 2” wood

pieces

ACHERON STACKING BRACKET

One Acheron can be stacked on top of the Acheron LF and
secured with the Acheron stacking brackets. The stacked
Acheron can be mounted with downtilt and uptilt angles of
0–16 degrees.

NOTE: The orientation of the Acheron to the

Acheron LF with the stacking bracket was
carefully optimized to minimize any acoustical arti­facts between the loudspeakers, as well as between
the loudspeakers and baffle walls.

Acheron Stacking Brackets

Acheron Stacking Bracket Kit Contents

The Acheron stacking bracket kit (PN 40.188.025.01)
includes the following parts.

Part Part number Quantity

Acheron stacking bracket (left) 45.188.043.01 1

Acheron stacking bracket (right) 45.188.044.01 1

3/8-16 x 1.5” shoulder screws 101.507 4

Large 1/2” flat washers 113.531 4

Small Flat washers 113.509 4

NOTE: The 3/8-16 x 1.5-inch screws required

for securing the stacking bracket to the
Acheron LF are shipped with the Acheron LF installed
in the top two screw holes on each side of the unit
(four total).

Stacking Acherons on Acheron LFs

To stack an Acheron on top of an Acheron LF:

1. Secure the Acheron LF to the floor with the floor mount
brackets at 0 degrees using the bottom bracket holes.
For more information, see “Floor Mounting Acherons and
Acheron LFs” on page 22.

Acheron and Acheron LF with Stacking Brackets

CAUTION: When stacking an Acheron on top

of an Acheron LF, the Acheron LF must be
secured to the floor with the floor mount brackets.
Floor mount the Acheron LF at 0 degrees using the
bottom bracket holes.

2. Stack the Acheron on top of the Acheron LF.

TIP: Optionally place two 1 x 2-inch wood

pieces (not included) across the top of the
Acheron LF, between it and the Acheron. The result­ing extra space between the loudspeakers will make
it easier to align the Acheron screw holes with the
brackets.

24

ACHERON OPERATING INSTRUCTIONS

Gasket side
toward loud­speaker

Shoulder screws
and larger washers

3. Remove the two 3/8-16 x 1.5-inch screws at the top of
each side of the Acheron LF (four total). These screws
will be used to secure the stacking bracket to the
Acheron LF.

4. Remove the two 3/8-16 x 1.5-inch screws at the bottom
of each side of the Acheron (four total). These screws will
not be needed for installing the stacking bracket.

5. Secure the left bracket to the left side of the Acheron LF
with two of the removed screws and two of the small flat
washers (included in the Acheron stacking bracket kit).
Use the bracket’s bottom screw holes and install the
bracket so its rubber gasket faces the loudspeaker.

6. Secure the right bracket to the right side of the
Acheron LF with the remaining two screws (previously
removed) and the remaining two small flat washers.
Install the bracket so its rubber gasket faces the loud­speaker.

7. Secure the stacking brackets to the Acheron with the
four 3/8-16 x 1.5-inch shoulder screws and four large
1/2-inch washers (both included with the Acheron stack­ing bracket kit). Insert the shoulder screws in the
bracket’s top slots but don’t yet tighten them completely.

TIP: If necessary, tip the Acheron slightly to

align its screw holes with the bracket holes.

■ To mount the Acheron with downtilt, orient the bracket

with the large end toward the rear of the loudspeakers.
For available downtilt angles, see “Stack Mount Downtilt
Angles” on page 26.

■ To mount the Acheron with uptilt, orient the bracket with

the large end toward the front of the loudspeakers. For
available uptilt angles, see “Stack Mount Uptilt Angles”
on page 27.

8. Adjust the angle of the stacked Acheron — anywhere
between 0 and 16 degrees — by tilting the unit up or
down so the screws slide through bracket slots.

9. Tighten all four shoulder screws to secure the stacking
bracket to the Acheron.

25

CHAPTER 5: MOUNTING

!

–16°

0°

–8°

–16°–8°

Front

Stacking Acherons with Downtilt and Uptilt

The Acheron stacking brackets can mount Acherons with
either downtilt or uptilt. Available angles are anywhere from
0–16 degrees. The direction in which the brackets are ori­ented determines whether the loudspeaker can be mounted
with downtilt or uptilt.

Stack Mount Downtilt Angles

When the stacking brackets are oriented with the bracket’s
large end toward the rear of the loudspeakers, the Acheron
can be mounted with downtilt angles of up to 16 degrees.

Acheron Floor Mount Bracket Oriented for Downtilt

Make sure to install the brackets so the rubber gasket faces
the loudspeaker. This ensures that the loudspeaker will not
get scratched when adjusting the downtilt angle.

Acheron LF and Stacked Acheron with 16-Degree Downtilt

CAUTION: When stacking an Acheron on top

of an Acheron LF, the Acheron LF must be
secured to the floor with the floor mount brackets. In
addition, the Acheron LF should not be mounted with
downtilt or uptilt.

26

Acheron Floor Mount Downtilt Angles

Stack Mount Uptilt Angles

+16°

0°

+8°

+16°+8°

Front

When the stacking brackets are oriented with the bracket’s
large end toward the front of the loudspeakers, the Acheron
can be mounted with uptilt angles of up to 16 degrees.

Acheron Floor Mount Bracket Oriented for Uptilt

Make sure to install the brackets so the rubber gasket faces
the loudspeaker. This ensures that the loudspeaker will not
get scratched when adjusting the uptilt angle.

ACHERON OPERATING INSTRUCTIONS

Acheron Floor Mount Uptilt Angles

27

CHAPTER 5: MOUNTING

28

CHAPTER 6: THE RMS REMOTE MONITORING SYSTEM

An optional RMS remote monitoring system module can be
installed in the Acheron, allowing it to be connected to an
RMS network. RMS allows real-time monitoring of multiple
Meyer Sound self-powered loudspeakers from a Windows­based computer. The RMS host computer communicates
with Meyer Sound loudspeakers (equipped with RMS mod­ules) via a simple twisted pair network, or an Ethernet net­work using an FT-10 to Ethernet adapter.

NOTE: For the latest RMS system require-

ments, go to www.meyersound.com

NOTE: RMS-equipped loudspeakers include a

Mute Jumper to enable the loudspeaker’s mute
and solo capability. Meyer Sound currently ships
RMS-equipped loudspeakers with the Mute Jumper
installed. These mute-enabled loudspeakers can be
identified by the blue “ME” sticker on the face of the
RMS module. Older RMS-equipped loudspeakers
can easily be mute-enabled by installing the Mute
Jumper. For more information, refer to the RMS User
Guide.

NOTE: The RMS software allows you to dis-

able Mute and Solo functions to eliminate any
possibility of accidentally muting loudspeakers. Mute
and solo capability can also be disabled by removing
the Mute Jumper from RMS modules. For more infor­mation, refer to the RMS User Guide.

.

RMS SOFTWARE

RMS software provides extensive system status and perfor­mance data for each loudspeaker, including amplifier volt­age, limiting activity, power output, fan and driver status, as
well as mute and solo capability. Loudspeakers are added to
the RMS network and assigned a node name during a one­time commissioning procedure where the loudspeaker is
identified by either entering its unique Neuron ID, or by
pressing its Service button.

RMS Add Loudspeaker Dialog Box

Once loudspeakers are identified on the RMS network, they
appear in the RMS software as icons and views; they are
also automatically added to the RMS database on the host
computer.

NOTE: RMS does not control AC power.

Acheron 80 RMS Icons

29

CHAPTER 6: THE RMS REMOTE MONITORING SYSTEM

The RMS software displays all loudspeakers on the network
in a panel with icons, Meter views, and Text views that can
be customized to suit your needs. Loudspeaker data is
updated 2–5 times per second. Individual loudspeakers can
be physically identified with the Wink option in RMS, which
lights the Wink LED on the RMS module for that particular
loudspeaker. Conversely, a loudspeaker can be identified in
the RMS software by pressing the Service button on the
loudspeaker’s RMS module.

RMS MODULE

The RMS user panel has three LEDs, two buttons, and two
Network connectors.

RMS Module

NOTE: The LEDs and buttons on the RMS user

panel are used exclusively by RMS and have
no effect on the acoustical or electrical activity of the
Acheron.

Service LED (Red)

The red Service LED provides the following feedback:

■ When unlit, the loudspeaker is successfully connected to

the network and commissioned.

RMS User Panel

Loudspeaker icons and views can be arranged to represent
how the loudspeakers have been deployed in the system.
Multiple panels can be saved and recalled for specific per­formances and venues.

NOTE: When the Acheron heat sink reaches

85° C (185° F), the On/Temp LED turns red,
while its loudspeaker icon in the RMS software turns
yellow — indicating the loudspeaker is running hot,
but still within safe operating limits. Make sure that
the loudspeaker is properly ventilated.

■ When blinking once every two seconds, the loudspeaker

is connected to the network but not yet commissioned in
the RMS software.

■ When lit continuously, the loudspeaker’s RMS hardware

has failed and may indicate that the module has been
damaged (contact Meyer Sound Technical Support).

Service Button

Pressing the Service button identifies the loudspeaker on
the RMS network and notifies the RMS software that the
loudspeaker is connected. You can simultaneously press the
Reset and Service buttons to reset the RMS module and
decommission the loudspeaker from the network (see
“Resetting the RMS Module” on page 31).

Wink LED (Green)

The green Wink LED lights when a signal is sent from the
RMS software by clicking the Wink button on the loud­speaker’s icon or on its Text view. This is useful for identify­ing the physical loudspeaker corresponding to a
loudspeaker icon in the RMS software.

30

Reset Button

Pressing the Reset button causes the RMS module’s firm­ware to reboot; this will not affect whether the loudspeaker
is commissioned (which is stored in flash memory). You can
simultaneously press the Reset and Service buttons to reset
the RMS module and decommission the loudspeaker from
the network (see “Resetting the RMS Module” on page 31).

Activity LED (Green)

The green Activity LED flashes continuously when the loud­speaker has been successfully commissioned.

Network Connectors

The two Weidmuller connectors transfer data to and from
the RMS network. Two connectors are provided to allow for
easy connection of multiple (daisy-chained) loudspeakers
on the network. Included with each RMS-equipped loud­speaker are RMS cable connectors and mounting blocks for
constructing RMS cables. The RMS blocks allow the cables
to be securely attached to the RMS module with screws.

ACHERON OPERATING INSTRUCTIONS

RESETTING THE RMS MODULE

You can use the Reset and Service buttons to reset the RMS
module, which will cause the module to be decommissioned
from the network.

To reset the RMS module:

1. Press and hold the Service button for 10 seconds.

2. While continuing to hold down the Service button, press
and hold the Reset button for 5 seconds.

3. After releasing the Reset button, continue holding down
the Service button for 5 seconds. The RMS module is
reset and the loudspeaker is decommissioned. The RMS
module’s red Service LED blinks.

31

CHAPTER 6: THE RMS REMOTE MONITORING SYSTEM

32

CHAPTER 7: SYSTEM DESIGN AND INTEGRATION TOOLS

Meyer Sound offers two comprehensive tools to assist with
the acoustical and functional requirements of system design
and optimization. This chapter introduces MAPP Online
Cinema, Meyer Sound’s patented online acoustical predic­tion tool, and SIM 3, a comprehensive system for measure­ment and analysis.

MAPP ONLINE CINEMA

MAPP Online Cinema is a powerful, cross-platform, Java­based application for accurately predicting the coverage
pattern, frequency response, impulse response, and maxi­mum SPL output of Meyer Sound cinema loudspeakers.

Residing on your local computer, the MAPP Online Cinema
client lets you configure Meyer Sound loudspeaker systems
and define the environment in which they will operate,
including air temperature, pressure, humidity, and even the
location and composition of walls. CAD (DXF) files contain­ing detailed venue information can also be imported.

The key to the accuracy of MAPP Online Cinema’s predic­tions is its exhaustive database of Meyer Sound loud­speaker measurements. Performance predictions for each
loudspeaker are based on 360 1/48th-octave-band mea­surements taken with a SIM audio analyzer in the Meyer
Sound anechoic chamber. The extraordinary consistency
between Meyer Sound loudspeakers guarantees that pre­dictions from MAPP Online Cinema will closely match their
actual performance.

MAPP Online Cinema predictions are requested by the client
software and sent via the Internet to the high-speed Meyer
Sound servers where high-resolution (magnitude and phase)
polar data is processed with sophisticated acoustical pre­diction algorithms. The resulting predictions are then
returned to and displayed on the local computer running the
MAPP Online Cinema client software.

TIP: Meyer Sound offers seminars and webinars

on using MAPP Online Cinema. For more infor-

mation, visit www.meyersound.com

.

MAPP Online Cinema Applications

With MAPP Online Cinema, you can:

MAPP Online Cinema

Sound system designers can use MAPP Online Cinema to
accurately predict the appropriate loudspeaker deployment
for each job, complete with coverage data, system delay
and equalization settings, and detailed design illustrations.
MAPP Online Cinema’s accurate, high-resolution predic­tions ensure that systems will perform as expected, thereby
eliminating unexpected coverage problems and minimizing
on-site adjustments.

■ Simulate different loudspeaker configurations to refine

system design and zero-in on the best coverage for
intended audience areas

■ Monitor loudspeaker interactions to locate destructive

interferences so that loudspeakers can be re-aimed and
repositioned as necessary

■ Place microphones anywhere in the sound field and pre-

dict their frequency response, impulse response, and
sound pressure

■ Determine delay settings for surround loudspeakers

■ Try out virtual Galileo equalization to determine optimum

real-world settings for the best system response

■ Generate and export system images for client presenta-

tions

33

CHAPTER 7: SYSTEM DESIGN AND INTEGRATION TOOLS

Using MAPP Online Cinema

MAPP Online Cinema is compatible with the following oper­ating systems:

■ Windows

■ Linux

■ Unix

■ Mac OS

Downloading and Installing MAPP Online Cinema

To use MAPP Online Cinema, you can register at the follow­ing link:

After entering your registration information, an email will be
sent to you with your user name, password, and the MAPP
Online Cinema download location. On-screen instructions
will guide you through the download and installation pro­cess.

The MAPP Online Cinema client software is regularly
upgraded to add support for the latest Meyer Sound loud­speakers, as well as to add feature enhancements. Most
upgrades are downloaded automatically when logging on to
a MAPP Online Cinema session. The MAPP Online Cinema
database includes all Meyer Sound EXP screen channel
loudspeakers, surround loudspeakers, subwoofers, and
processors.

®

®

®

10.4 and later

http

://meyersound.com/products/mapponline/cinema/

register/

Source Independent Measurement Technique

The SIM 3 audio analyzer implements Meyer Sound’s source
independent measurement technique, a dual-channel
method that accommodates statistically unpredictable exci­tation signals. Any excitation signal within a desired fre­quency range can be used to obtain highly accurate
measurements for acoustical or electronic systems. For
example, concert halls and loudspeaker systems can be
captured during a performance and used as a SIM 3 test
signal, so you can:

■ View measurement data as amplitude versus time

(impulse response) or amplitude and phase versus fre­quency (frequency response)

■ Utilize a single-channel spectrum mode

■ View frequency domain data within a logarithmic fre-

quency axis

■ Determine and internally compensate for propagation

delays using the SIM 3 Delay Finder

SIM 3 Applications

The SIM 3’s primary applications are testing and aligning
loudspeaker systems, which entails:

■ Measuring propagation delays between subsystems to

determine appropriate polarities and delay times

■ Measuring variations in frequency response caused by

the acoustical environment and the placement and inter­action of loudspeakers to determine corrective equaliza­tion

SIM 3 MEASUREMENT SYSTEM

The SIM 3 audio analyzer is a high-resolution audio mea­surement system comprised of software, hardware, micro­phones, and accessory cables. The SIM 3 is optimized for
measuring audio frequencies with resolutions up 1/48th of
an octave, allowing you to apply precise corrections to bal­ance system response using frequency and phase domain
information.

34

■ Optimizing subwoofer integrations

■ Optimizing loudspeaker arrays

The SIM 3 is also versatile and accurate enough for the fol­lowing applications:

■ Microphone calibration and equalization

■ Transducer evaluation and correction

■ Echo detection and analysis

■ Vibration analysis

■ Architectural acoustics

■ Underwater acoustics

APPENDIX A: ACHERON 80 AND ACHERON 100 SPECIFICATIONS

Acheron 80 and Acheron 100 Specifications

ACOUSTICAL

Operating Frequency Range 37 Hz – 18 kHz

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

Frequency Response 38 Hz – 17 kHz ±4 dB

Note: Measured free field with 1/3 octave frequency resolution at 4 meters.

Phase Response 700 Hz to 17 kHz ±30°

Maximum Peak SPL 139 dB

Note: Measured free field with music referred to 1 meter.

Dynamic Range >110 dB

Coverage Acheron 80: 80° horizontal by 50° vertical

Acheron 100: 100° horizontal by 50° vertical

Crossover 580 Hz

Note: At this frequency, both transducers produce equal sound pressure levels.

TRANSDUCERS

Low Frequency One high-power 15” cone driver with neodymium magnet

Nominal impedance: 4 Ω
Voice coil size: 4”
Power-handling capability: 1200 W (AES)
Note: Power handling measured using AES standards: transducer driven continuously for two
hours with a band limited noise signal having a 6 dB peak-average ratio.

High Frequency One 4” compression driver

Nominal impedance: 8 Ω
Voice coil size: 4”
Diaphragm size: 4”
Exit size: 1.5”
Power-handling capability: 250 W (AES)
Note: Power handling measured using AES standards: transducer driven continuously for two
hours with a band limited noise signal having a 6 dB peak-average ratio.

AUDIO INPUT

Type Differential, electronically balanced

Maximum Common Mode Range ±15 V DC, clamped to earth for voltage transient protection

Connectors Female XLR input with male XLR loop output

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

DC Blocking None on input, DC block through signal processing

CMRR >50 dB, typically 80 dB (50 Hz – 500 Hz)

RF Filter Common mode: 425 kHz

Differential mode: 142 kHz

TIM Filter <80 kHz, integral to signal processing

35

APPENDIX A: ACHERON 80 AND ACHERON 100 SPECIFICATIONS

Acheron 80 and Acheron 100 Specifications

Nominal Input Sensitivity 10 dBV (3.2 V rms, 4.5 V peak) continuous is typically the onset of limiting for noise and music

Input Level Audio source must be capable of producing +20 dBV (10 V rms, 14 V peak) into 600 Ω to pro-

duce the maximum peak SPL over the operating bandwidth of the loudspeaker

AMPLIFIER

Type Complementary MOSFET output stages (class AB/H)

Output Power 1685 W total (1125 W low channel, 560 W high channel)

Note: Amplifier wattage rating based on the maximum unclipped burst sine-wave 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.

Total Output 3370 W peak

THD, IM TIM <.02%

Load Capacity 4 Ω low channel, 8 Ω high channel

Cooling Forced air cooling, two internal fans (one ultra low-speed fan, one reserve fan)

AC POWER

Connectors 250 V NEMA L6-20 (twistlock) inlet or IEC 309 male inlet

Voltage Selection Automatic, two ranges, each with high-low voltage tap (uninterrupted)

Safety Agency Rated Operating
Voltage

Turn On/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)

Maximum Long-Term Continu­ous Current

Burst Current 6.4 A rms (115 V AC); 3.2 A rms (230 V AC); 7.2 A rms (100 V AC)

Ultimate Short-Term Peak Cur­rent

Inrush Current 7 A peak (115 V AC); 7 A peak (230 V AC); 10 A peak (100 V AC)

PHYSICAL

Enclosure Premium birch plywood

Finish Low gloss, black textured

Mounting 3/8” threaded points on side corners for optional bracket adapters, which allow the Acheron

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

Weight Weight 173 lbs (78.47 kg)

ENVIRONMENTAL

Operating Temperature 0° C to +45° C

Non Operating Temperature <–40° C or >+75° C

Humidity to 95% at 35° C

Operating Altitude to 4600 m (15,000 ft)

Non Operating Altitude to 95% at 35° C

95–125 V AC; 208–235 V AC; 50/60 Hz

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

Note: 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.

26 A peak (115 V AC); 14 A peak (230 V AC); 28 A peak (100 V AC)

to be mounted to floors with uptilt or downtilt, as well as on top of the Acheron LF (also with
uptilt or downtilt)

36

Acheron 80 and Acheron 100 Specifications

31.00

[787mm]

20.50

[521mm]

35.00

[889mm]

21.00

[533mm]

20.00

[508mm]

10.75

[273mm]

Shock 30 g 11 msec half-sine on each of 6 sides

Vibration 10 Hz – 55 Hz (0.010 m peak-to-peak excursion)

ACHERON 80 AND ACHERON 100 COMPLIANCE

ACHERON 80 DIMENSIONS

ACHERON OPERATING INSTRUCTIONS

Acheron 80 Dimensions

37

APPENDIX A: ACHERON 80 AND ACHERON 100 SPECIFICATIONS

31.00

[787mm]

20.50

[521mm]

35.00

[889mm]

21.00

[533mm]

20.00

[508mm]

10.75

[273mm]

ACHERON 100 DIMENSIONS

Acheron 100 Dimensions

38

APPENDIX B: ACHERON LF SPECIFICATIONS

Acheron LF Specifications

ACOUSTICAL

Operating Frequency Range 37 Hz – 370 Hz

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

Frequency Response 38 Hz – 340 Hz ±4 dB

Note: Measured free field with 1/3 octave frequency resolution at 4 meters.

Phase Response 60 Hz to 230 Hz ±30°

Maximum Peak SPL 136 dB

Note: Measured free field with music referred to 1 meter. SPL for the Acheron LF calibrated to
complement the Acheron 80 and Acheron 100 in the common frequency range.

Dynamic Range >110 dB

Crossover 200 Hz

Note: Below this frequency, both Acheron LF transducers are active. Above this frequency,
one transducer rolls off to avoid interactions in the higher frequencies (shorter wavelengths) of
the Acheron 80 and Acheron 100.

TRANSDUCERS

Low Frequency Two high-power 15” cone drivers with neodymium magnets

Nominal impedance: 4 Ω
Voice coil size: 4”
Power-handling capability: 1200 W (AES) each
Note: 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.

AUDIO INPUT

Type Differential, electronically balanced

Maximum Common Mode Range ±15 V DC, clamped to earth for voltage transient protection

Connectors Female XLR input with male XLR loop output

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

DC Blocking None on input, DC block through signal processing

CMRR >50 dB, typically 80 dB (50 Hz – 500 Hz)

RF Filter Common mode: 425 kHz

Differential mode: 142 kHz

TIM Filter <80 kHz, integral to signal processing

Nominal Input Sensitivity 10 dBV (3.2 V rms, 4.5 V peak) continuous is typically the onset of limiting for noise and music

Input Level Audio source must be capable of producing +20 dBV (10 V rms, 14 V peak) into 600 Ω to pro-

duce the maximum peak SPL over the operating bandwidth of the loudspeaker

AMPLIFIER

Type Complementary MOSFET output stages (class AB/H)

39

APPENDIX B: ACHERON LF SPECIFICATIONS

Acheron LF Specifications

Output Power 2250 W total (1125 W low channels)

Note: Amplifier wattage rating based on the maximum unclipped peak voltage the amplifier
will produce into the nominal load impedance: low frequency channels, 67 V rms (95 V peak)
into 4 ohms.

Total Output 4500 W peak

THD, IM TIM <.02%

Load Capacity 4 Ω low channels

Cooling Forced air cooling, two internal fans (one ultra low-speed fan, one reserve fan)

AC POWER

Connectors 250 V NEMA L6-20 (twistlock) inlet or IEC 309 male inlet

Voltage Selection Automatic, two ranges, each with high-low voltage tap (uninterrupted)

Safety Agency Rated Operating
Voltage

Turn On/Turn Off Points 85–134 V AC; 165–264 V AC

Current Draw

Idle Current 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

Burst Current 19.0 A rms (115 V AC); 9.5 A rms (230 V AC); 22.0 A rms (100 V AC)

Ultimate Short-Term Peak Cur­rent

Inrush Current 7 A peak (115 V AC); 7 A peak (230 V AC); 10 A peak (100 V AC)

PHYSICAL

Enclosure Premium birch plywood

Finish Low gloss, black textured

Mounting 3/8” threaded points on side corners for optional bracket adapters, which allow the

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

Weight Weight 185 lbs (83.91 kg)

ENVIRONMENTAL

Operating Temperature 0° C to +45° C

Non operating Temperature <–40° C or >+75° C

Humidity to 95% at 35° C

Operating Altitude to 4600 m (15,000 ft)

Non operating Altitude to 95% at 35° C

Shock 30 g 11 msec half-sine on each of 6 sides

Vibration 10 Hz – 55 Hz (0.010 m peak-to-peak excursion)

95–125 V AC; 208–235 V AC; 50/60 Hz

8.8 A rms (115 V AC); 4.4 A rms (230 V AC); 10.0 A rms (100 V AC)

Note: 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.

39 A peak (115 V AC); 20 A peak (230 V AC); 45 A peak (100 V AC)

Acheron LF to be secured to floors; the Acheron 80 and Acheron 100 can be mounted on top
of the Acheron LF with uptilt or downtilt

40

ACHERON LF COMPLIANCE

31.00

[787mm]

20.50

[521mm]

36.18

[919mm]

9.90

[251mm]

20.00

[508mm]

ACHERON LF DIMENSIONS

ACHERON OPERATING INSTRUCTIONS

Acheron LF Dimensions

41

APPENDIX B: ACHERON LF SPECIFICATIONS

42

Meyer Sound Laboratories Inc.
2832 San Pablo Avenue
Berkeley, CA 94702

www.meyersound.com
T: +1 510 486.1166
F: +1 510 486.8356

Meyer Sound. All rights reserved.

Acheron Operating Instructions, PN

© 2009, 2010

05.188.005.01 B