QSC DCM series User manual

DCM Series
Digital Cinema Monitor & Crossover System
U S E R M A N U A L

The DCM hardware unit and DCM Commander software are the property of QSC Audio Inc. Information in
this document is subject to change without notice and does not represent a commitment on the part of QSC
Audio. The software described here is furnished under a licensing agreement. It is against the law to copy
the software on any medium except as specifically allowed in the licensing agreement.
DCM Commander is a trademark of QSC Audio Products, Inc; Windows and Windows 95 are trademarks of
Microsoft Corporation; IBM is a registered trademark of IBM Corporation; Pentium is a registered trade-
mark of Intel Corporation.
1999 QSC Audio Inc. All rights reserved. Printed in USA.
Document Number 600019-A

I. Introduction ................................................................................ 1
II. System Requirements .................................................................... 2
III. Package Contents ....................................................................... 3
III. System Concepts ........................................................................ 4
A. System Design Features ................................................. 4
1. QSC Amplifier Dataports ............................................. 4
2. Programmable routing and crossover settings ........................... 5
3. DSP processing ..................................................... 5
4. Speaker Database ................................................... 5
5. Fault Analysis ...................................................... 5
6. Password Security .................................................. 5
7. Emergency Bypass .................................................. 6
8. Surround Insert Connections (Dolby SA-10).............................. 6
9. Active Surround Ready ............................................... 6
Front and Rear Panel Drawings ............................................. 7
IV. DCM Hardware Description ........................................................... 12
A. Frontpanel Features ..................................................... 12
1. Power On/Off ...................................................... 12
2. Audio Monitoring ................................................... 12
3. Diagnostics / Indicators .............................................. 13
4. Test Jacks ......................................................... 14
5. Emergency Bypass .................................................. 14
B. Rear Panel Features ..................................................... 14
1. Amplifier Dataports ................................................. 15
2. From Processor Output ............................................... 14
3. RS-232 Connection ................................................. 15
4. Surround Insert ..................................................... 15
5. Emergency Bypass Levels ............................................ 15
6. Terminal Strip Connections ........................................... 16
7. Power Input ........................................................ 16
V. DCM Commander Windows PC Software ............................................ 17
A. System Control Overview ................................................ 17
B. Software Installation .................................................... 17

C. Starting The Program .................................................... 17
D. Working with Configuration Files .......................................... 17
1. Your First Configuration File .......................................... 17
2. Editing a Configuration File ........................................... 18
E. Main Control Screen ..................................................... 19
1. File ............................................................... 19
2. Communications .................................................... 20
i. Connect / Disconnect ............................................ 20
ii. Get Configuration from DCM ...................................... 20
iii. Write Configuration to DCM ...................................... 20
iv. Serial Port ..................................................... 20
3. Configuration ....................................................... 20
i. General Configurations ........................................... 20
a. General Info ................................................ 20
b. General Config .............................................. 21
c. Installed Outputs ............................................ 21
c. Surround ................................................... 22
d. Security ................................................... 22
ii. Amp and Speaker Configuration Settings ........................... 23
a. Amplifier Models ........................................... 23
b. Speaker Models ............................................ 24
c. Speaker Arrangement ........................................ 25
d. Impedence Limits ........................................... 26
iii. Speaker Database ............................................... 27
a. Default & Custom Database .................................. 27
iv. Monitor Gain Levels ............................................. 27
4. Crossover .......................................................... 28
i. DSP Settings .................................................... 28
a. Screen Signal Path .......................................... 28
b. Screen Settings ............................................. 29
i. Sub DSP Settings ................................................ 30
a. Sub Signal Path ............................................. 30
b. Sub Settings ............................................... 31
ii. Mute Settings .................................................. 32

iii. Fault Diagnostics ............................................... 32
5. Help .............................................................. 33
i. About .......................................................... 33
ii. Contents ....................................................... 33
F. DCM 1st Time Troubleshooting ............................................ 34
1. No PC to DCM-1 Communications ..................................... 34
2. No audio from front panel monitor speaker .............................. 34
3. Some front panel LEDs don't light ..................................... 34
VI. System Installation ...................................................................... 35
A. System Hardware Connections ............................................ 35
1. Required Cables Overview ............................................ 35
2. Power Connection ................................................... 35
3. Control Computer Connection ......................................... 35
4. DataPort Connections ................................................ 35
5. Processor Connection ................................................ 35
6. Hearing Impaired Connection ......................................... 36
7. Powered Subwoofer Connection ....................................... 36
8. Surround Insert Connection ........................................... 36
B. System Calibration (typical) ............................................... 36
1. Theater - audio level adjustments ..................................... 37
2. Emergency Bypass levels ............................................. 37
3. Monitoring - audio mix adjustments .................................... 37
C. System Calibration (advanced) ............................................ 37
1. Speaker Frequency Adjustments ....................................... 37
2. Setting Delay Times ................................................. 37
D. System Installation Troubleshooting ....................................... 39
1. If no sound in the Theater... ........................................... 39
2. If one audio channel is missing... ...................................... 39
3. If theater audio is distorted... ......................................... 39
4. If switching to bypass does not restore sound... .......................... 39
Appendix 1: Cable Details - Pinouts ........................................................ 41
Appendix 2: DCM Specifications ........................................................... 45
Appendix 3: Address & Telephone Information ............................................. 47

II.INTRODUCTION
The QSC Audio DC series (together with QSC DCA amplifiers) is designed to perform all of the electronic
functions required for the audio portion of a cinema playback system except for the cinema processor unit
(for example, Dolby, Sony, or dts) and the speakers.
The DCM series consists of one of three hardware units (DCM-1, DCM-2, and DCM-3) and the PC based
control software called the DCM Commander. The DCM-1 supports a typical Dolby 6 ch. 2-way system. The
DCM-2 supports a typical Dolby 6 ch. 2-way or 3-way system, and the DCM-3 supports a Sony 8 ch 2-way or
3-way system. These systems include many outputs which are paralled to allow for maximum theater con-
nection flexibility.
Notice that the DCM series takes advantage of the DCA amplifier DataPorts to allow extremely easy and
reliable connection to all of the amplifiers, with all inputs and monitoring signals being connected by one
low cost, mass termination cable. This cabling system allows a QSC cinema equipment rack to be wired up
much faster than traditional XLR or barrier strip termination products!
Another critical feature is the ability to download standard or custom configuration adjustments via the se-
rial port. For example, in a 15 theater megaplex with similar rooms and equipment, an installation techni-
cian can calibrate a DCM unit to the appropriate speakers and room configuration ONE TIME, and then
load these settings into the other 14 DCM units and be finished!
We are extremely proud of many of the "ground breaking" features contained within these products.
Thank you for your interest!
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III.SYSTEM REQUIREMENTS
DCM Commander software is designed to control only one DCM hardware unit at a time. In order to test
the functionality of this software together with the DCM hardware unit, you must have at least the
following:
A QSC DCM Digital Cinema Monitor unit
The DCM Commander software diskettes or CDROM
An IBM-compatible PC with at least a 486 (or equiv) processor
Windows 95 or Windows 98
Minimum 16MB of RAM
Minimum 1MB of available hard disk storage space
A 3.5" 1.44MB floppy drive ro CDROM drive (depending on software provided)
An available RS-232 serial port
A display capable of at least 640X480 resolution in 16 colors.
A standard DB9 RS-232 cable (male to female)
To complete a full Cinema System, you will also need a cinema processor, QSC DCA amplifiers, speakers,
and cables.
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IV.PACKAGE CONTENTS
Open the box and remove the contents. You will find the following items:
This user manual
An envelope containing the DCM Commander installation diskettes (or CDROM) with the
software license agreement
A linecord for connection to AC power
The DCM hardware unit main assembly (either a DCM-1, or a DCM-2, or a DCM-3)
If anything is missing, immediately contact your salesman.
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V.SYSTEM CONCEPTS
A.System Design Features
The DCM series Digital Cinema Monitor has many unique features which combine to make this the
most cost effective and versatile systems solution in the industry. This system addresses the following
needs:
Installer Feature
Provides Monitor and Crossover functions in one box.
Minimizes the amount of cabling required. (only one cable per amplifier contains
two signal inputs, two signal returns, power on/standby control and two channels of
load monitoring!).
Minimizes setup time (especially in megaplexs with similar rooms).
Preprogrammed speaker setting database for most common theater speaker brands
and models (supplied by QSC).
Indicates if something is wrong with the sound system (plus gives simple diagnostics to
help find problems).
An emergency bypass system allows center channel sound to pass through the system
even if there is a major problem.
Allows easy routing and crossover adjustments.
Protects system adjustments from tampering.
Sound quality is state-of-the-art (high dynamic range).
Projectionist Features:
Easy to verify that all of the audio in the theater is okay.
Automatic monitoring will light an LED if there is trouble with a speaker output.
A backup system (emergency bypass) can be easily activated.
1.QSC Amplifier DataPorts
The QSC DataPort connectors greatly reduce the complexity of wiring between the DCM unit and
the amplifiers. These DataPorts replace the need for preparing XLR or screw terminal connections
for the main amp audio inputs AND they replace the connections required to monitor the outputs
of the amplifier speaker connections. Another unique feature of the QSC Cinema System is the
ability to automatically analyze voltage and current status to determine shorts or opens in the
speaker cables. All of these connections are completed via the ONE DataPort mass termination
cable. A VGA computer monitor cable (15 pin male to computer monitor cable (15 pin male to
computer monitor cable (15 pin male to computer monitor cable (15 pin male to computer moni-
tor cable (15 pin male to 15 pin male) can be used, but verify that all pins have "unique" connec-
tions on both sides of the cable. QSC can supply these cables with high quality shielded audio
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wires within the cable for maximum interference protection.
2.Programmable routing and crossover settings
Almost all of the internal circuitry within the DCM series can be adjusted using commands over
the RS-232 port from the DCM Commander software. Configuration files can be stored to a dis-
kette and used for other DCMs. For example, if a megaplex theater has many rooms with similar
size and equipment, an installation technician can adjust one DCM unit for best results, and then
download all of these settings to other DCM units. The functions that can be controlled remotely
are: crossover settings for screen channel outputs, mutes, multiple equalizer settings per channel,
delay times, output volume levels, some channel assignments, monitor mix balance adjustments,
and more.
3.DSP processing
Digital filtering of audio signals is known to have several advantages over analog solutions. DSP
(digital signal processor) IC chips allow extremely accurate and reliable control over frequency and
time adjustments (boost, cut, cutoff frequency, delay time), and stability (immunity from tempera-
ture variations). The audio path of the DCM uses conversion circuitry (changing the signal from
analog to digital and back again) which is designed to minimize all background noise and react to
the dynamic range of any film track. In other words, the quality of the DCM signal path is better
than any state-of-the-art cinema format available!
4.Speaker Database (preprogrammed settings)
QSC has worked with the leading suppliers of theater speakers to obtain the optimum settings for
the most common theater speaker models. This database is easily loaded into the DCM hardware
unit and the DCM Commander software offers features to organize, store, and edit these settings.
This feature guarantees that your installation starts with technically optimized settings before you
begin adjusting for room characteristics !
5.Fault Analysis
All signals from the film sound processor are compared with the signals that are at the output of
the amplifier to verify that sound has made it completely through the system. Each amplifier out-
put channel has sensors which measure both the voltage and the current to verify proper opera-
tion. For example, if there is signal at the DCM unit input but there is no signal at the output of
the amplifier, then the fault indicator will light. Or, if an amplifier output cable is shorted or open,
the fault indicator will light. Pressing the Diagnostics button will indicate which channel has this
fault condition.
6.Password Security
The crossover settings that you create can make a dramatic difference in the sound quality within
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the theater. Many installers pride themselves on being able to adjust the electrical parameters
(crossover points, equalization, delay, etc) to exactly compliment the speaker and room interac-
tions. As such, their ability to set these parameters is a "value added" service which deserves
protection from competitors. We have therefore included a security system where you can pro-
tect your settings within the DCM from being uploaded and copied by the DCM Commander soft-
ware. Only your unique password will allow viewing or editing of the crossover settings, however,
should you forget your password, an entirely new configuration can be loaded.
7.Emergency Bypass
One of the main design goals of the DCM series was to offer a foolproof method of getting sound
into the theater "no matter what"! To accomplish this, a passive crossover has been built into the
center channel routing so that even with a total loss of power to the DCM, a usable sound path
will be maintained. Activation of this bypass is done by the projectionist via a front panel Emer-
gency Bypass switch.
8.Surround Insert Connections
There has been discussion concerning format changes to the cinema surround channels. To allow
maximum flexibility, we have included an extremely easy method of routing the surround signals
out of the DCM (to an external processor box such as a Dolby SA-10), and back into the DCM for
routing to the QSC amplifiers.
9.Active Surround Ready
The DCM-2 and DCM-3 units are prepared for the addition of circuitry that allows crossover and
equalization of the surround channels. Please contact the QSC factory if you have an application
which requires this function.
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7

8

9

10

DCM-2 and DCM-3
DataPort ABC and EF Detail
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VI.DCM HARDWARE DESCRIPTION
A.Front Panel Features
The front panel of the DCM series resembles traditional cinema monitor products. This was done to
allow a typical machine room projectionist a well known and easy to understand user interface. This
also follows our design goal of presenting an easy to understand product to the user while still offering
a state-of-the-art cinema sound control system for installation technicians and advanced users.
1.Power On/Off
The power on/off switch acts as a master control for not only the DCM, but also all of the amplifi-
ers connected into the system (as long as the amplifier power switches are "on"). This is possible
because the DataPort connections on all of the amplifiers have a standby control pin which is
grounded when the DCM is turned off. Because of the unique zero inrush feature on DCA amplifi-
ers, no additional startup sequencing is required.
The Emergency Bypass circuitry requires that the center channel amplifier remain on if the front
panel switch is in the EMERGENCY position. This causes the following situations:
When the Emergency Bypass = NORMAL, DCM power on/off also switches the QSC amplifiers
between on/standby.
When the Emergency Bypass = EMERGENCY, DCM power on/off also switches the QSC amplifiers
between on/standby except the center channel amplifier (connected to DCM DataPort B) which
remains on.
2.Audio Monitoring
All of the processor and amplifier audio signals can be routed to a monitor speaker on the front
panel so one can verify proper operation.
The PROC / AMP button selects monitoring of the cinema processor or amplifier output signals.
PROC is short for PROCESSOR and routes the signals that are coming from the cinema processor
(at the DCM input) to the front panel speaker. The AMP selection monitors the signals from the
output of the QSC amplifiers (right from the speaker output terminals!). After the AMPS / PROC
choice has been made, the individual channel buttons determine exactly which signals are routed
to the front panel monitor speaker.
Processor monitoring is very simple. Select the PROC position and then select the desired
L,LC,C,RC,R,SL,SR, or SUB position.
Amplifier monitoring includes selections for the L,LC,C,RC,R channels (just like the PROC selec-
tions), but offers additional monitoring of all of the additional amplifier outputs.
There are physically 3 Surround Left (SL) and Surround Right (SR) amplifiers available for connec-
tion to the speakers on the theater side walls. These are able to create three distinct "zones"
where volume controls can be adjusted.
One typical installation would be to connect the SL1 and SR1 signals to the speakers closest to
the screen. SL2 and SR2 in the next set of speakers further away from the screen and the SL3 /
SR3 connections furthest back in the theater. In Surround Decoder applications, the SL3 / SR3
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setting monitors the speakers on the backwall.
Other installations might require speaker sets where some speakers are along the theater side
walls where other speakers are under a balcony overhang. By connecting these speakers as "zo-
nes", the sound levels will be much easier to balance.
Any of these amplifier outputs can be verified by selecting them to be routed to the DCM monitor
speaker.
The DCM also has 4 Subwoofer outputs. Each of these outputs can be individually selected for
monitoring on the front panel speaker.
The front panel monitoring logic allows combining amplifier channels to verify individual signals or
combinations of signals.
NOTE: All combining of the individual frequency outputs (2-way or 3-way) is done automatically,
so all front panel monitoring is of a full frequency signal.
3.Diagnostics / Indicators
The Diagnostics / Indicator section includes an extremely simple method of verifying proper sys-
tem operation and performing basic troubleshooting.
The Power indicator indicates whether the DCM unit is on or off.
The Input Clip indicator is helpful in verifying that the cinema format processor is not over-driving
the DCM input circuitry.
The Load Fault indicator is a unique and powerful feature which verifies that signal inputs into
the DCM actually make it through the DCM, the DataPort cables, and the amplifier unit all the
way to the speakers, and that the speaker connections are not electrically shorted or open. All of
these measurements are being performed constantly (without user action) on ALL output channels
and any unusual readings will light the Load Fault LED. If the Load Fault LED is lit, pressing the
Diagnostics button (and holding it pressed) will cause the problem channels indicator LED to
light. This information will let you inspect the system cabling for that channel and troubleshoot
the problem.
There are two types of indication: If the PROC LED and AMP LED are on, there is no amplifier
detected at that DCM amplifier connector. If the AMP LED is on, the amplifier on at that output is
measuring a short or an open on its output terminals.
REMEMBER: If you configured the DCM Commander software to not have certain channels (for
example there is no SUB 3 or SUB 4), these channels WILL NOT indicate any faults.
==========
VERY IMPORTANT: The Load Fault detection software within the DCM unit uses a complex
averaging algorithm which compares input signals to output signals and measures voltage and
current on all amplifier outputs. To sense real world conditions, these measurements must be
found to be "out of range" many times before the Load Fault condition is indicated on the DCM
front panel. So if you are simulating fault conditions, you MUST have a "real-world" signal level
through the device (full signal input), and the fault condition must exist for several minutes before
the front panel Load Fault LED will light. This extra fault verification time eliminates false
triggering which would be confusing to a user. In conclusion, Just shorting the output terminals
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