Axxess AXDSPX-GM31 Digital signal processor and T-harness — for select 2019-up Chevy and GMC vehicles without a factory amplifier

Features

Overview: The Axxess AXDSPX-GM31 interface lets you add aftermarket amplifiers to the factory radio in select 2019-up Chevrolet and GMC vehicles without a factory amplifier. It features 10 individually assignable pre-amp outputs, each with independent 31 band graphic EQ, high-, low-, and band-pass filters, along with up to 10ms of delay time for each channel. The DSP interface retains all parking sensor chimes and OnStar voice prompts, with adjustable levels.

Compatibility: The AXDSPX-GM31 can be used with the following Chevrolet & GMC vehicles with factory non-amplified sound systems. Compatibility can be verified by accessing the vehicle's RPO (Regular Production Option) code list, usually located on the inside of the glove box.

Configuration: All configuration of the Axxess AXDSPX-GM31 is done through your connected Bluetooth enabled smartphone or tablet after downloading the AX-DSP-X mobile app, available at the Apple App (iOS 12.1 or higher) and Google Play stores. Configuration options can be saved, recalled, and reset to default from your device. A Password can be assigned to lock the interface from tampering. The Lock Down feature saves all selected settings, and must be done before closing the app or cycling the key, otherwise all setting changes will be reset to their default. Configuration options include:

• Outputs: Allows you to select how many output channels will be used and their location in the vehicle. The first 5 Outputs are pre-assigned to L&R Front, L&R Rear, and Subwoofer, with Outputs 6-10 not used. These can be assigned and used for individual driver use, such as a mid-range or woofer speaker. Along with their Location labeling, Outputs can be grouped together, for simplified equalization. Each Output also features options for Invert, which reverses the phase, and Mute, for easier tuning of each individual channel.
• Crossover: Each Output channel has its own Crossover, with options for High-Pass, Low-Pass, and Band-Pass. An intuitive virtual slide-bar lets you easily select the desired cutoff frequency while displaying it above the slide-bar. If Band-Pass is selected, two frequency sliders are displayed for the High- and Low-Pass settings, with both frequencies displayed above the slide-bar.
• Equalizer: All Output channels can have a 31-band graphic equalizer applied to the signal. EQ bands range from 20Hz to 20kHz, with ±10dB of adjustment for each band.
• Delay Adjust: The sound from each Output channel can be delayed, if desired. Output channel Delay is entered in inches with up to 99" of Delay available, based on the measured distance from each speaker to the driver's head-rest location.
• Input/Levels: This Configuration screen provides the following:
  • Chime Volume: Warning tones can be adjusted for a balanced signal. Chime Volume range is 1-10, with indications for Low, Medium, and High.
  • Clipping Level: The AXDSPX-GM31 can detect clipping of the audio signals and reduce the level by 20dB for a period of time to prevent speaker damage. Option includes On/Off, and 1-10 adjustment scale.
  • Amp Turn-On: The connected amplifiers (sold separately) can be set to activate when Accessory power is turned on (Always On), or when a signal is detected from the radio (Signal Sense). A Turn-On Delay option can be set from 0-10 seconds.
  • Subwoofer Input: The Subwoofer Output can be driven from the sum of the Front and Rear inputs (Front + Rear), or directly from the Subwoofer input (Subwoofer), if provided by the factory system.

  Note: It is important to Lock Down all settings after performing any configuration changes. If not, closing the app or cycling the ignition key will reset all options back to factory default.

Bass Knob: A remote bass control is provided for individual adjustment of the Subwoofer output channel. The Bass Knob features 5' of bare-ended wire, for connection to the provided T-harness, and can be mounted under a dash edge using the provided mounting hardware.

Installation: Designed to integrate into select Chevrolet and GMC non-amplified factory sound systems, the AXDSPX-GM31 includes a wiring T-harness that plugs in between the factory radio and the factory radio harness. Additional T-harness connections plug into the included interface module, as well as provide the audio output RCA jacks, which include:

• Outputs 1-4: These RCAs are color coded to match the "standard" wiring configuration;
  • White: Left Front
  • Gray: Right Front
  • Green: Left Rear
  • Purple: Right Rear
• Outputs 6-10: These RCAs are assignable and are not color coded.
• Subwoofer: A pair of Red/White RCAs provides the Subwoofer signal output.
• Turn-On Output: A Blue/White Amp Turn-On wire can be used to activate connected amplifiers. This output can be assigned to activate with the ignition key or with radio signal sense, and can be delayed up to 10 seconds.

Specifications:

• Input Channels: 6
• Input Impedance: 1MΩ
• Input Level: High or Low
• Input Type: Differential Balanced
• Input Voltage:
  • High-Level: 0-28V (peak-to-peak)
  • Low-Level: 0-4.9V (peak-to-peak)
• Output Channels: 10
• Output Voltage: Up to 5V RMS
• Output Impedance: 50Ω
• Equalizer Type: 31 Band Graphic, ±10dB
• THD: <0.03%
• Frequency Response: 20Hz-20kHz
• Crossover: LPF, BPF, or HPF per channel
• Crossover Type: Linkwitz-Riley 24dB/oct. slope
• Sampling: 48kHz
• S/N Ratio: 105dB @ 5V RMS
• Operating Voltage: 10-16VDC
• Operation Current Draw: 150mA
• Standby Current Draw: 7mA