AudioControl DQDX Six-Channel Pre-amp Processor

Introduction

The AudioControl DQDX is a compact, six-channel, high-performance signal processor designed to enhance aftermarket audio systems. It features independent multi-channel equalization and signal delay for precise system tuning, along with a selectable electronic crossover for optimal setup. The DQDX aims to 'Make Good Sound Great' by providing advanced audio control and customization.

Important Safety Instructions

Please read and follow all safety instructions carefully:

1. Read and keep these instructions.
2. Heed all warnings and follow all instructions.
3. Do not use the apparatus near water or block ventilation openings.
4. Clean only with a dry cloth.
5. Do not install near heat sources.
6. WARNING: Improper installation may lead to permanent injury or death. Installation must be performed by qualified personnel, taking care to avoid damage to vehicle systems.
7. Provide adequate +12V and Ground wiring.
8. Use rubber grommets for wiring protection through metal openings.
9. Only use manufacturer-specified attachments/accessories.
10. Refer all servicing to qualified personnel.
11. Do not expose the apparatus to dripping or splashing.
12. Replace fuses only with the correct type and value when the apparatus is powered off.
13. Exposure to high sound pressure levels may lead to permanent hearing loss; take precautions to protect your hearing.

The lightning flash symbol indicates the presence of uninsulated "dangerous voltage" presenting a risk of electric shock. The exclamation point symbol alerts users to important operating and maintenance instructions. To reduce the risk of electric shock, do not disassemble the apparatus; refer servicing to qualified personnel.

[recycling-symbol] Recycling notice: Please recycle this apparatus responsibly at a facility equipped for electronic waste. Contact local recycling leaders for assistance.

Key Features

• User-friendly Signal Delay for acoustical alignment of front, rear, and subwoofer channels.
• Individual equalization controls for front, rear, and subwoofer channels for precise system tuning.
• Fully adjustable 24dB/Octave Linkwitz-Riley electronic crossover.
• PFM (Program Frequency Match) Subsonic Filter.
• Six channels of RCA line-level inputs.
• ACR-3 Dash Control Remote for subwoofer level control, bypassing processing, and setting signal delay.
• Discrete Input and Output level controls with clipping indicators.
• Remote turn-on output provides a 12-volt trigger for amplifiers.
• Built-in Pink Noise for easy Signal Delay and Equalizer tuning.
• Bulletproof 5-year warranty (when installed by an authorized AudioControl dealer).

Quick Installation Information

For a smooth setup, follow these guidelines. Refer to system diagrams on pages 14-16 for visual examples.

1. Mount the DQDX in a location safe from spills and accessible for top panel controls.
2. Install the DQDX in the signal path between your source unit and amplifier(s). If your source unit has front, rear, and subwoofer outputs, connect them accordingly. If only front and rear outputs are available, connect them to the DQDX and engage the "Sub to Front" jumper to route the low-pass signal to the subwoofer outputs.
3. Connect RCA cables from the DQDX outputs to your amplifier inputs. If unsure, consult an authorized AudioControl dealer.
4. Connect +12V power, ground, and turn-on wires, ensuring the fuse is in place.
5. Connect the amplifier trigger input to the DQDX's 12-volt trigger output.
6. Ensure aftermarket amplifier input gain controls are set to minimum (counter-clockwise).
7. Turn on the system and level match the DQDX to your source unit and amplifiers.
8. Select the correct crossover point on the DQDX for Hi-Pass (front/rear) and Low-Pass (subwoofer) outputs. It is recommended to disable crossovers on the source unit and use the DQDX's crossover.
9. Set the DQDX Signal Delay Mode to 'Set-Up'.
10. Use the ACR-3 Dash Control to adjust signal delay between Left and Right channels.
11. Tap the ACR-3 Dash Control to adjust signal delay between front and subwoofer outputs.
12. Change the DQDX Signal Delay Mode back to 'Normal'.
13. Set the equalization controls for front, rear, and subwoofer channels. Use an audio analyzer for best results, or engage the DQDX's pink noise output (by holding the ACR-3 knob for 4 seconds) to aid in equalizer setup.
14. Sit back and enjoy the sound.

A Guided Tour of the DQDX

The DQDX offers several key control areas:

1. RCA Line-Level Inputs: Six inputs accept signals from your source unit's RCA outputs. The 'Front to Sub' circuitry can route front input channels to subwoofer outputs via an internal jumper.
2. Input and Output Level Controls: Adjust signal levels from your source unit to match your amplifier inputs for optimal performance. Refer to the Level Matching section for detailed instructions.
3. Equalization Controls: Dedicated controls for Front, Rear, and Subwoofer outputs allow for custom system tuning. See the Equalization Optimization section for guidance.
4. 24dB/Octave Linkwitz-Riley Crossover: This audiophile-grade crossover accurately routes frequencies to amplifier channels, providing a flat response and avoiding phase irregularities common in other designs.
5. Signal Delay Mode: Allows selection between 'Set-Up' mode for adjusting signal delays and 'Normal' mode for subwoofer level control via the ACR-3 remote.
6. Ground: Connect to a verified chassis ground, preferably the battery, to avoid noise issues common with factory ground wires.
7. +12V Power: Connect to a 12-Volt source using a fused connection not exceeding 2 Amps.
8. Remote In: Connect to your source unit's 12-volt trigger wire or a reliable vehicle ignition-switched source for power control.
9. Remote Out: Connect the 12-volt turn-on lead for your aftermarket amplifiers here to prevent clicks or pops during power cycles.
10. Maximized Indicators: LEDs indicate signal levels near clipping. They should flicker only occasionally when the system is at maximum volume after proper level matching.
11. Power LED: Indicates the unit is powered on when connected correctly.
12. Remote Level Control ACR-3: In 'Set-Up' mode, it adjusts signal delays. In 'Normal' mode, it controls subwoofer level. Pressing and holding for 4 seconds outputs pink noise for EQ/delay setup. A momentary press in 'Normal' mode bypasses EQ and Signal Delay processing.
13. Pre-Amp Outputs: RCA outputs connect directly to amplifier inputs. Do not connect speakers or home appliances directly to the DQDX.
14. Parallel Outputs: A unique circuit allows the Front input signal to feed the Subwoofer outputs when no dedicated Subwoofer input is available.

Under the Covers - Internal Jumpers

Internal jumpers allow for advanced configuration:

• J9 Input Balancing: Set to UNBALANCED for most systems. Use BALANCED if RCA connections create a ground loop causing a whine.
• J10 PFM Jumper: Controls the cutoff frequency of the subwoofer output (Programmable Frequency Match), acting as a low-pass limit to protect speakers.
• J11 Front to Sub Jumper: When set to ON, routes the low-pass signal (defined by crossover selection) to the Sub outputs, useful when source unit only has front/rear outputs.
• J12 Ground Isolation Selector: Helps prevent alternator noise by providing alternative grounding connections. Ship default is 'isolated' for best results. Ensure the system is OFF before changing jumpers.

System Diagrams

The manual includes diagrams illustrating system configurations:

• System #1: Basic DQDX installation with 4-channel input and 6-channel output, showing connections to a subwoofer amplifier and a 4-channel amplifier.
• System #2: Typical DQDX installation, depicting a common setup with the DQDX, amplifiers, and speakers.
• System #3: Illustrates using the DQDX with The Epicenter for enhanced sound quality and bass, showing connections to amplifiers and speakers.

Signal Delay Operation

Signal delay corrects acoustical alignment issues caused by speaker placement in vehicles. By delaying signals to specific speakers, the DQDX ensures sound from all speakers arrives at the listener's ear simultaneously.

Setup Process:

1. Download the AudioControl Signal Delay Set-Up App (iOS) or use your ears for setup.
2. Connect power and ground, set crossover points, and input/output levels. Turn the DQDX Signal Delay knob to 'Set-Up' mode (Orange LED on chassis, blue LED on ACR-3 blinks).
3. Zeroing Delay: In 'Set-Up' mode, push ACR-3 knob until blue LED blinks and red LED is solid (Left/Right delay mode). Turn knob clockwise until Mute Clicks cease. Then, push ACR-3 knob until blue LED blinks and red LED is off (Front/Sub delay mode). Turn knob clockwise until Mute Clicks cease. All delays are now zeroed.
4. Adjusting Delay: Play music with clear vocals. For Left/Right delay, push ACR-3 knob (blue LED blinking, red LED solid) and turn counter-clockwise to delay the left front speaker. Each detent represents milliseconds. For Front/Subwoofer delay, push ACR-3 knob (blue LED blinking, red LED off) and turn counter-clockwise to add delay to front speakers and the subwoofer.
5. Once satisfied, return the DQDX Signal Delay knob to 'Normal' mode.

Equalization Optimization

Achieve personalized sound by adjusting equalization. For best results, use a Real Time Analyzer (RTA) like the AudioControl SA-4140. Alternatively, use your ears or consult an authorized dealer.

Setup with Pink Noise:

1. Play pink noise through the system by holding the ACR-3 button for 4 seconds.
2. Position the RTA microphone at the driver's ear level.
3. Analyze the frequency response curve. Adjust equalization controls to balance frequencies, aiming for clarity, detail, and punch.
4. Start by cutting excessive peaks before boosting deficient ranges.

Frequency Bands:

• Sub-bass (100 Hz and below): Crucial for bass response. Aim for 6-9 dB boost over other frequencies, but avoid over-boosting which can damage speakers.
• Midbass (100 Hz to 300 Hz): Transition area. Autosound systems often have peaks here due to speaker resonance; these can mask midrange frequencies.
• Midrange (300 Hz to 3 kHz): Contains vocals and instruments. Keep this range smooth and balanced for clear imaging and staging.
• Treble (3 kHz and Up): Adds sparkle and detail. Avoid excessive boosting, which can sound unnatural.

Digitally-Selectable Electronic Crossover

The DQDX features a 24dB/Octave Linkwitz-Riley crossover to separate frequencies for different speakers. The crossover frequency selector allows precise tuning between 50Hz and 500Hz. Choosing the correct crossover point based on speaker manufacturer specifications is vital for speaker reliability and sound quality.

To select a frequency, turn the crossover selector counter-clockwise to the starting position and count the clicks until the desired frequency is reached.

Level Matching

Proper level matching ensures maximum output from your system without hiss or clipping.

1. Set source unit fader/balance to center and amplifier gain to minimum.
2. Disconnect RCA outputs between DQDX and amplifiers.
3. Play dynamic music at approximately 1/4 volume on the source unit.
4. Adjust DQDX input level controls clockwise until the Input Maximized LED flickers. Do not turn past this point.
5. Adjust DQDX output level control until the Output Maximized LED flickers.
6. Lower source unit volume and turn off the system. Reconnect RCAs.
7. Adjust amplifier gain according to manufacturer specifications.

Parallel Outputs & Remote Level Control - ACR-3

Parallel Outputs: The DQDX's 'Front to Sub' circuit allows the front input signal to feed subwoofer outputs when no subwoofer input is available, enabling front, rear, and subwoofer output channels.

Remote Level Control - ACR-3: This dash-mountable remote controls signal delay in 'Set-Up' mode and subwoofer level in 'Normal' mode. Pressing the ACR-3 knob bypasses EQ and delay processing, allowing you to hear the system's performance with and without processing. Holding the knob for 4 seconds outputs pink noise for EQ setup.

Placement and Mounting: The ACR-3 can be mounted under the dash using its bracket or a custom hole. Ensure it is within reach and visible. Disconnect the battery before installation. Mark mounting holes, drill pilot holes, and secure with screws.

ACR-3 Custom Installation

For a flush-mounted look, drill a 9/32" (7 mm) hole for the control, a 3/32" (2.3 mm) hole for the lock tab, and 1/8" (3 mm) holes for the LEDs. Ensure no wires are drilled through during installation.

Block Diagram of the DQDX

The DQDX block diagram illustrates the signal path through the processor. Inputs (Front, Rear, Sub) are processed through Equalization (EQ), Signal Delay, and Crossover filters (Hi Pass for Front/Rear, PFM/Lo Pass for Sub) before reaching the outputs. The diagram also shows the Pink Noise generation and control functions.

The WARRANTY

AudioControl offers a warranty designed to ensure customer satisfaction. Key conditions for warranty coverage include:

1. Register your DQDX online at www.audiocontrolregistration.com within 15 days of purchase.
2. Keep your sales receipt as proof of purchase.
3. The DQDX must have been purchased from an authorized AudioControl dealer.
4. Only authorized personnel (AudioControl factory or written authorization) may service the unit; unauthorized service voids the warranty.
5. The warranty is void if the serial number is altered or removed, or if the unit is used improperly (e.g., physical damage, incorrect connections, abuse).

If installed by an authorized US AudioControl dealer, the warranty extends to five years. Otherwise, it is one year. AudioControl may choose to repair or replace the unit.

LEGALESE SECTION: This warranty provides specific legal rights that vary by state. AudioControl is not liable for consequential damages. Failure to register warranty information negates service claims.

DQDX SPECIFICATIONS

©2018 AudioControl, Inc. All rights reserved.

Company Information

AudioControl, Making Good Sound Great, and DQDX are trademarks of AudioControl Inc. This manual was conceived, designed, and written in the Pacific Northwest.

AudioControl
Making Good Sound Great™
22410 70th Ave West
Mountlake Terrace, WA 98043 USA
Phone 425-775-8461 • www.audiocontrol.com