dbx PX User manual

User Manual
Powered Speaker Optimizer
Featuring
Powered Speakers
PX
®

WARNING FOR YOUR PROTECTION
PLEASE READ THE FOLLOWING:
KEEP THESE INSTRUCTIONS
HEED ALL WARNINGS
FOLLOW ALL INSTRUCTIONS
THE APPARATUS SHALL NOT BE EXPOSED TO DRIPPING OR SPLASHING LIQUID AND NO OBJECT
FILLED WITH LIQUID, SUCH AS VASES, SHALL BE PLACED ON THE APPARATUS
CLEAN ONLY WITH A DRY CLOTH.
DO NOT BLOCK ANY OF THE VENTILATION OPENINGS. INSTALL IN ACCORDANCE WITH THE
MANUFACTURER’S INSTRUCTIONS.
DO NOT INSTALL NEAR ANY HEAT SOURCES SUCH AS RADIATORS, HEAT REGISTERS, STOVES,
OR OTHER APPARATUS (INCLUDING AMPLIFIERS) THAT PRODUCE HEAT.
ONLY USE ATTACHMENTS/ACCESSORIES SPECIFIED BY THE MANUFACTURER.
UNPLUG THIS APPARATUS DURING LIGHTNING STORMS OR WHEN UNUSED FOR LONG
PERIODS OF TIME.
Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two
blades with one wider than the other. A grounding type plug has two blades and a third grounding
prong. The wide blade or third prong are provided for your safety. If the provided plug does not fit
your outlet, consult an electrician for replacement of the obsolete outlet.
Protect the power cord from being walked on or pinched particularly at plugs, convenience recep-
tacles, and the point where they exit from the apparatus.
Use only with the cart stand, tripod bracket, or table specified by the manufacture, or sold with the
apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid
injury from tip-over.
Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been
damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects
have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate
normally, or has been dropped.
MAINS DISCONNECT: The plug shall remain readily operable. For rack-mount or installation where
plug is not accessible, an all-pole mains switch with a contact separation of at least 3 mm in each
pole shall be incorporated into the electrical installation of the rack or building.
FOR UNITS EQUIPPED WITH EXTERNALLY ACCESSIBLE FUSE RECEPTACLE: Replace fuse with same
type and rating only.
MULTIPLE-INPUT VOLTAGE: This equipment may require the use of a different line cord, attachment
plug, or both, depending on the available power source at installation. Connect this equipment only
to the power source indicated on the equipment rear panel. To reduce the risk of fire or electric shock,
refer servicing to qualified service personnel or equivalent.
SAFETY INSTRUCTIONS
NOTICE FOR CUSTOMERS IF YOUR UNIT IS EQUIPPED WITH A POWER CORD.
WARNING: THIS APPLIANCE SHALL BE CONNECTED TO A MAINS SOCKET OUTLET WITH A
PROTECTIVE EARTHING CONNECTION.
The cores in the mains lead are coloured in accordance with the following code:
GREEN and YELLOW - Earth BLUE - Neutral BROWN - Live
As colours of the cores in the mains lead of this appliance may not correspond with the coloured
markings identifying the terminals in your plug, proceed as follows:
•The core which is coloured green and yellow must be connected to the terminal in the plug
marked with the letter E, or with the earth symbol, or coloured green, or green and yellow.
•The core which is coloured blue must be connected to the terminal marked N or coloured
black.
•The core which is coloured brown must be connected to the terminal marked L or coloured
red.
This equipment may require the use of a different line cord, attachment plug, or both, depending
on the available power source at installation. If the attachment plug needs to be changed, refer
servicing to qualified service personnel who should refer to the table below. The green/yellow
wire shall be connected directly to the units chassis.
CONDUCTOR WIRE COLOR
Normal Alt
L LIVE BROWN BLACK
N NEUTRAL BLUE WHITE
E EARTH GND GREEN/
YEL GREEN
WARNING: If the ground is defeated, certain fault conditions in the unit or in the system to
which it is connected can result in full line voltage between chassis and earth ground. Severe
injury or death can then result if the chassis and earth ground are touched simultaneously.
The symbols shown above are internationally accepted symbols that warn of
potential hazards with electrical products. The lightning flash with arrowpoint in
an equilateral triangle means that there are dangerous voltages present within
the unit. The exclamation point in an equilateral triangle indicates that it is
necessary for the user to refer to the owner’s manual.
These symbols warn that there are no user serviceable parts inside the unit.
Do not open the unit. Do not attempt to service the unit yourself. Refer all
servicing to qualified personnel. Opening the chassis for any reason will void
the manufacturer’s warranty. Do not get the unit wet. If liquid is spilled on the
unit, shut it off immediately and take it to a dealer for service. Disconnect the
unit during storms to prevent damage.
IMPORTANT SAFETY INFORMATION

DECLARATION OF
CONFORMITY
Manufacturer’s Name: dbx Professional Products
Manufacturer’s Address: 8760 S. Sandy Parkway
Sandy, Utah 84070, USA
declares that the product:
Product name: DriveRack PX
Note: Product name may be suffixed by the EU.
Product option: None
conforms to the following Product Specifications:
Safety: IEC 60065 (7th ed. 2001)
EMC: EN 55013 (2001+A1)
EN 55020 (1998)
Supplementary Information:
The product herewith complies with the requirements of the Low
Voltage Directive 72/23/EEC and the EMC Directive 89/336/
EEC as amended by Directive 93/68/EEC.
Director of Engineering - dbx
8760 S. Sandy Parkway
Sandy, Utah 84070, USA
Date: January 23, 2008
European Contact: Your local dbx Sales and Service Office or
Harman Music Group
8760 South Sandy Parkway
Sandy, Utah 84070, USA
Ph: [phone]
Fax: [phone]
ELECTROMAGNETIC
COMPATIBILITY
This unit conforms to the Product Specifications noted on the
Declaration of Conformity. Operation is subject to the following two
conditions:
this device may not cause harmful
interference, and
this device must accept any interference received, including interfer-
ence that may cause undesired operation.
Operation of this unit within significant
electromagnetic fields should be avoided.
use only shielded interconnecting cables.
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U.K. MAINS PLUG WARNING
A molded mains plug that has been cut off from the cord is unsafe.
Discard the mains plug at a suitable disposal facility.
NEVER UNDER ANY CIRCUMSTANCES SHOULD YOU
INSERT A DAMAGED OR CUT MAINS PLUG INTO A 13
AMP POWER SOCKET.
Do not use the mains plug without the fuse cover in place.
Replacement fuse covers can be obtained from your local retailer.
Replacement fuses are 13 amps and MUST be ASTA approved to
BS1362.
If you want to dispose this product, do not mix it with general household waste. There is a
separate collection system for used electronic products in accordance with legislation that
requires proper treatment, recovery and recycling.
Private household in the 25 member states of the EU, in Switzerland and Norway may return their used
electronic products free of charge to designated collection facilities or to a retailer (if you purchase a similar
new one).
For Countries not mentioned above, please contact your local authorities for a correct method of disposal.
By doing so you will ensure that your disposed product undergoes the necessary treatment, recovery and
recycling and thus prevent potential negative effects on the environment and human health.
IMPORTANT SAFETY INFORMATION

Section 1- Introduction ......................... 1
0.1 Defining the DriveRack PX............... 1
0.2 Service Contact Info....................... 2
0.3 Warranty....................................... 3
Section 2- Getting Started ..................... 4
2.1 Rear Panel Connections .................. 4
2.2 Front Panel Connections ................. 4
2.3 Quick Start ................................... 6
2.4 DriveRack PX Wizard....................... 8
Section 3 - Editing Functions.................. 15
3.1 Basic Navigation Modes .................. 15
3.2 Button Array Overview.................... 15
3.3 Navigating the High-pass and
Bandpass Filter (SETUP) Section ...... 16
3.4 Navigating the
Subharmonic Section...................... 16
3.5 Navigating the
Comp/Limiter Section..................... 17
3.6 Navigating the EQ Section .............. 17
3.7 Navigating the AFS Section ............. 18
3.8 Navigating the Utility Section ......... 18
3.9 Navigating the Wizard Section......... 18
3.10 Navigating the Recall Section ........ 19
3.11 Navigating the Store Section ......... 19
Section 4 - Operating Functions............... 20
4.1 Preset Definition ........................... 20
4.2 Navigating Factory Presets .............. 20
4.3 Editing Factory Presets................... 21
Section 5 - Detailed Parameters ............... 23
5.1 Stereo Input Graphic EQ ................. 23
5.2 AFS (Automatic Feedback
Suppression)....................................... 23
5.3 Subharmonic Synthesizer ................ 25
5.4 Compressor/Limiter........................ 26
5.5 Filter (SETUP) .............................. 28
5.6 Output Parametric EQ (3-band)........ 28
Section 6 - Application Guide................... 29
6.1 Mains-Only Setup (No Subs) ............ 29
6.2 Two Mains/One Subwoofer Setup...... 30
6.3 Two Mains/Two Subwoofers Setup .... 31
6.4 Sub with Satellites Setup................ 32
Section A - Appendix............................... 33
A.1 Factory Reset................................ 33
A.2 Power Up Quick Key Options............ 33
A.3 Specifications ............................... 35
A.4 Auto-EQ Optimization Tips.............. 36
A.5 Crossover Diagrams ........................ 36
A.6 Block Diagram............................... 37
A.7 Preset List / Supported Speakers ..... 38
A.8 System Setup and Gain Structure ..... 39
DriveRack®PX
Table of Contents
®

Section 1- Introduction
The dbx DriveRack® PX Powered Speaker Optimizer has everything you need to get the most
out of your stereo powered speaker system. It even includes stereo or mono subwoofer
support. With the included dbx M2 measurement mic, Auto-EQ corrects for audible
deficiencies in the room environment. Our patented Advanced Feedback Suppression (AFS™)
kills nasty feedback, allowing problem-free operation at higher sound levels, while our
patented Subharmonic Synthesizer™ extends bass response for enhanced bottom end. With
all that, you also get classic dbx compression and the protection offered by our graceful
PeakPlusTM limiting. Your ears, your audience, and your powered speakers will forever thank
you.
0.1 Defining the DriveRack PX
The dbx DriveRack PX is the most effective way to manage all aspects of powered loudspeaker
management for public address system applications. The DriveRack PX essentially becomes the
only device that you will need between the mixer and the powered speakers. The following
are just some of the features of the DriveRack PX.
DriveRack® PX features:
Stereo Feedback Elimination with 12 feedback notch filters
Stereo 28-band Graphic EQ
Classic dbx® Compressor
120A Subharmonic Synthesizer
Stereo Multi-band Parametric EQ
Stereo PeakPlus™ Limiters
Pink Noise Generator
Auto-EQTM with 28-Band RTA
JBL® and other popular powered speakers included in Setup Wizard
JBL® preset speaker combinations
dbx M2 Measurement Mic and zippered pouch included
Front panel RTA-Mic XLR input with phantom power
25 User Programs / 25 Factory Programs
2 Channel XLR Input
2 Channel XLR Output
2 Channel XLR Sub Output
24-Bit ADC/24-Bit DAC, >110 dB Dynamic Range
dbx Type IVTM Conversion System
Full Graphic LCD Display
By including every form of processing necessary to drive the signal from the mixer to the
power amp, the DriveRack® PX allows you to eliminate all other processing devices normally
found in large and cumbersome traditional drive rack systems of the past.
The DriveRack PX Powered Speaker Optimizer includes two balanced XLR inputs and two
balanced XLR outputs, as well as two balanced XLR subwoofer output connectors.
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DriveRack®PX Section 1
Introduction
1
®

0.2 Service Contact Info
If you require technical support, contact dbx Customer Service. Be prepared to accurately
describe the problem. Know the serial number of your unit - this is printed on a sticker
attached to the bottom panel. If you have not already taken the time to fill out your warranty
registration card and send it in, please do so now.
Before you return a product to the factory for service, we recommend you refer to the manual.
Make sure you have correctly followed installation steps and operation procedures. If you are
still unable to solve a problem, contact our Customer Service Department at [phone]
for consultation. If you need to return a product to the factory for service, you MUST first
contact Customer Service to obtain a Return Authorization Number.
No returned products will be accepted at the factory without a Return Authorization Number.
Please refer to the Warranty information on the following page, which extends to the first
end-user. After expiration of the warranty, a reasonable charge will be made for parts, labor,
and packing if you choose to use the factory service facility. In all cases, you are responsible
for transportation charges to the factory. dbx will pay return shipping if the unit is still under
warranty.
Use the original packing material if it is available. Mark the package with the name of the
shipper and with these words in red: DELICATE INSTRUMENT, FRAGILE! Insure the package
properly. Ship prepaid, not collect. Do not ship parcel post.
DriveRack®PX
Section 1 Introduction
®
2

0.3 Warranty
This warranty is valid only for the original purchaser and only in the United States.
1. The warranty registration card that accompanies this product must be mailed within 30
days after purchase date to validate this warranty. Proof-of-purchase is considered to be the
burden of the consumer.
2. dbx warrants this product, when bought and used solely within the U.S., to be free from
defects in materials and workmanship under normal use and service.
3. dbx liability under this warranty is limited to repairing or, at our discretion, replacing
defective materials that show evidence of defect, provided the product is returned to dbx
WITH RETURN AUTHORIZATION from the factory, where all parts and labor will be covered up
to a period of two years. A Return Authorization number must first be obtained from dbx by
telephone. The company shall not be liable for any consequential damage as a result of the
product’s use in any circuit or assembly.
4. dbx reserves the right to make changes in design or make additions to or improvements
upon this product without incurring any obligation to install the same additions or
improvements on products previously manufactured.
5. The foregoing is in lieu of all other warranties, expressed or implied, and dbx neither
assumes nor authorizes any person to assume on its behalf any obligation or liability in
connection with the sale of this product. In no event shall dbx or its dealers be liable for
special or consequential damages or from any delay in the performance of this warranty due to
causes beyond their control.
DriveRack®PX Section 1
Introduction
3
®

2.1 Rear Panel Connections
GND
SUB OUTPUTS
Manufactured under the following U.S. Patents:
3,789,143; 4,182,993; 6,195,029; 7,203,324.
PX
R
UL 60065 IEC 60065
120V - 60Hz
IEC Power Cord Receptacle
The DriveRack® PX comes with a power supply that will accept voltages ranging from 100V-
120V at frequencies from 50Hz-60Hz. An IEC cord is included. EU versions accept 220V-240V
at frequencies from 50Hz-60Hz.
Sub Outputs Left/Mono and Right
Connect your subwoofer(s) here (optional).
Outputs Left and Right
Connect your main speakers here.
Inputs Left/Mono and Right
The input section of the DriveRack PX offers two electronically balanced XLR connectors.
Ground Lift Switch
The ground lift switch lifts the pin 1 chassis ground of both input XLR connectors.
+4dBu / –10dBV Switch
This switch selects between –10dBV and +4dBu nominal operating levels. When the switch is
in the “in” position, the –10dBV operating level is selected. When the switch is in the “out”
position, +4dBu is selected.
2.2 Front Panel Connections
SETUP
AFS
RECALL
SUBHARMONIC
COMP/LIMITER
UTILITY
PRESET
NEXT PG
STORE
EQ
WIZARD
Inputs Sub Outs
UTILITY
PREV PG
WIZARD
0
6
12
24
36
SIG
Headroom dB Headroom dB Headroom dB
Outputs
Limiter
DriveRack PX
®
Powered Speaker
Optimizer
0
6
12
24
36
SIG
0
6
12
24
36
SIG
RTA Mic Input Jack
This balanced XLR input is used for the connection of the dbx M2 RTA microphone, which
allows the user to optimize the powered speaker settings and the EQ settings of any room
through the use of the System Setup and Auto-EQ Wizards.
RTA MIC Input Selector
Pressing the RTA MIC input button will engage the front panel RTA input XLR connector and
start the Auto-EQ wizard.
DriveRack®PX
Section 2 Getting Started
®
4
Section 2- Getting Started

Data Wheel
The Data wheel of the DriveRack® PX is used to scroll through the preset menu, load presets,
select parameters and edit parameter values.
LCD Display
The backlit LCD display of the DriveRack® PX provides the user with all of the vital processing
information of the DriveRack® PX including: signal routing, effect block editing and Wizard
functions. The display will also notify the user if any internal clipping is taking place within
the unit. The following message will appear: CLIP.
Function Buttons
The function buttons of the DriveRack® PX allow direct access to all editing and navigating
functions of the DriveRack® PX. The functions of the aforementioned buttons are as follows:
<PREV PG> - Moves to the previous page in the currently selected menu.
<NEXT PG> - Moves to the next page in the currently selected menu.
<SETUP> - Press and release to enter the high-pass and bandpass filter editor. Press and hold
to enter the first page of the Powered Speaker Setup Wizard.
<SUBHARMONIC> - Press and release to enter the dbx 120A Subharmonic Synthesizer editor.
<COMP/LIMITER> - Press and release to cycle through the compressor editor and output
limiter processing editor.
<EQ> - Press and release to cycle through the graphic EQ and parametric EQ editors. Press
and hold to enter the first page of the Auto-EQ Wizard.
<PRESET/[RECALL]> - Press and release to return to the preset view, showing preset number,
preset bank (user or factory), preset name, and signal path. Press and hold to activate the
[RECALL] button function which allows the selection and loading of a new preset.
<STORE/[UTILITY]> - Press and release to enter the Store menu, which allows the user to
store the current state to a user preset. Press and hold to enter the UTILITY menu to adjust
LCD contrast, Auto-EQ plot selection (RTA or GEQ), and Sales Banner on/off.
<AFS> - Press and release to enter the AFS editor. Press and hold to enter the first page of
the AFS Wizard.
Stereo Input Meters
The DriveRack® PX provides the user with two independent six segment input meters that
range from Signal Present (–48 dBFS) to 0 dBFS (maximum output). These meters monitor the
signal level right after the input module.
Stereo Output Meters
The DriveRack® PX provides the user with two independent six-segment output meters that
range from Signal Present to 0 dBFS (maximum output).
Mono/Stereo Subwoofer Output Meters
The DriveRack® PX provides the user with two independent six-segment subwoofer output
meters that range from Signal Present to 0 dBFS (maximum output).
Threshold Meters
The threshold meters indicate that the threshold level has been exceeded within the Limiter
section, and gain reduction may be taking place within the specific output channel.
DriveRack®PX Section 2
Getting Started
5
®

2.3 Quick Start
For those of you that wish to jump right in, the following information has been provided to
act as a quick start guide for optimizing performance of the DriveRack® PX.
Signal Path Block Diagram
The following diagram shows the logical and intuitive signal path of the input, signal
processing modules, and output of the DriveRack® PX.
GEQ
Meters
Left (Mono) Input
Right Input
Left
Right
Left (Mono)
Right
Mic Input
Outputs
Stereo Compressor
AFS Notch Filters
SubHarmonic Synth
3-Band PEQ2-Band PEQ
PeakPlus LimiterPeakPlus Limiter
High-Pass and
Band-Pass Filter Section
Stereo/Mono
Pink Noise
Micr Pre amp
RTA
Meters
Sub Outputs
Connections
When setting up the DriveRack® PX, make connections as follows:
Always make connections prior to applying power to the unit.
Connect the output from the sending device (mixer) to one or both of the two XLR
input connectors shown below.
Make output connections from “Outputs” XLR connectors shown below to the inputs of
the powered speakers.
If a subwoofer or subwoofers are to be used, make output connections from “Sub
Outputs” XLR connectors shown below to the inputs of the subwoofers.
GND
SUB OUTPUTS
Manufactured under the following U.S. Patents:
3,789,143; 4,182,993; 6,195,029; 7,203,324.
PX
R
UL 60065 IEC 60065
120V - 60Hz
If you will be “pinking” the room through the use of the RTA, connect the dbx M2 RTA
microphone to the front-panel XLR input.
IMPORTANT- It is imperative that the powered speakers are turned off prior to applying
power to the DriveRack® PX. Always make sure that your powered speakers are the last
item turned on and the first turned off.
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DriveRack®PX
Section 2 Getting Started
®
6