JL Audio VX400/4i
Local Pickup Only
Amplifier plus DSP
We heard a lot of pre-launch buzzing about JL Audio’s VXi Series amplifiers, which combine JL Audio’s latest amplifier technology with powerful signal processing. JL Audio teamed up with micro-device maker AKM™ to create this customized processor-amp hybrid. They also improved the amp’s Class D performance by shortening the signal path through the amp, placing the output capacitor banks nearer the outputs, and using up-to-date DirectFET® MOSFET output devices, resulting in higher efficiency, reliability, and audio quality.
75 watts RMS by four channels
The VX400/4i 4-channel amplifier puts out 75 watts RMS per channel and features 6 channels of digital signal processing. It can power the front and rear speakers in your car, and provide a processed signal for a separate subwoofer amplifier. You could also use this amplifier in bridged, 2-channel mode to power a couple of high-performance speakers or subwoofers with 200 watts RMS each.
The 24-bit 96 kHz processing for each channel includes signal routing and mixing, 10-band parametric EQ, time-alignment, high- and low-pass filters, and output level control with 0.1 dB precision. In addition to tuning the audio signal, the processor provides a master clock signal for the Class D amplification, increasing audio accuracy.
Remote control only
You make all your settings and adjustments from your compatible device running JL Audio’s TüN™ software.
- PC and Mac OS: TüN 3.0 — requires a USB connection (6′ cable included with amp)
- Android and iOS tablets: TüN Mobile — requires Bluetooth connection and the VXi-BTC Bluetooth communicator (sold separately)
- Android phones and Apple iPhones: TüN Express (for Basic setups only) — requires Bluetooth connection and the VXi-BTC Bluetooth communicator (sold separately)
Other accessories you may want with this amp
This VXi amplifier features JLid™ inter-device connection ports for JL Audio’s proprietary network system for controlling data. The DRC-205 digital remote control lets you adjust the master volume, subwoofer level, switch between up to six preset tunings, and indicates the amp’s status via LED. An optional VXi-HUB network hub comes in handy when you have three or more VXi amps in your system, coordinating all the adjustments and controls. A FiX 82 or a FiX 86 can be used to remove factory sound processing, for higher-fidelity factory system integration for your VXi amplifier.
VX400/4i connection panel
- 4-channel car amplifier
- 75 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)
- 200 watts RMS x 2 bridged at 4 ohms
- Class D amplifier design with NexD2™ switching amp technology
Digital Signal Processing:
- 24-bit 96 kHz digital processing
- DSP adjustments and settings made via computer, tablet, or smartphone running JL Audio’s TüN app via USB, via Bluetooth (tablets and phones) with BTC Bluetooth option
- 3 Project Levels of tuning: Basic, Advanced, Expert
- input routing and mixing
- adjustable gain controls with clip indication
- fully adjustable high-pass, low-pass, and bandpass filters
- selectable filter slopes (6, 12, 18, 24, 30, 36, 42, 48 dB/octave)
- 10-band EQ (graphic in Basic, parametric in Advanced and Expert modes)
- phase and polarity control
- time alignment in 0.01 ms (1/8″) increments
- differential-balanced inputs eliminate noise coming from your vehicle’s electrical system
- preamp and speaker-level inputs (speaker wire to RCA adapter required for speaker-level input)
- high-level inputs — up to 16 volts RMS (about 60 watts)
- DC offset or signal sensing auto turn-on eliminates the need for remote lead
- 2-channel digital input and output (S/PDIF: up to 24-bit 192 kHz in, 24-bit 96 kHz out)
- 2-channel analog preamp output (4V RMS)
- JLid™ connections for optional Network Hub, Bluetooth Communicator, and Digital Remote Control
- USB connection for device running TüN app (6-foot cable included)
- wiring, fuse, and hardware not included with amplifier
- 4-gauge power and ground leads and a 40-amp fuse recommended
- 9-1/16″W x 2-1/8″H x 6-11/16″D
- warranty: 2 years
- Our 60-day money-back guarantee
- MFR # 98636
What’s in the box:
JL Audio VX400/4i owner’s manual
- 4-Channel amplifier
- Power connector
- 14″ Analog Input harness (15-pin D-Sub/6 RCA)
- 18″ ABCD Speaker output harness
- 6′ USB cable (Type A USB on one end and Type B USB on other end)
- 4 Corner caps
- Corner cap tool
- 2 Silver thumbscrews
- 2 Black hex cap machine screws
- 2.5mm Hex wrench
- 3mm Hex wrench
- JL Audio logo badge
- Connection Guide
- Registration card
Features & specs
|RMS Power Output (Watts x Channels)||75 x 4|
|Peak Power Output (Watts x Channels)||—|
|Power at 2 Ohms (Watts x Channels)||100 x 4|
|Bridged Power (Watts x Channels)||200 x 2|
|Minimum Impedance Bridged||4|
|Minimum Impedance Unbridged||2|
|Best Frequency Response||12-24k Hz|
|THD at Rated RMS Power||1%|
|Signal to Noise Ratio||80 dB|
|Low-Pass Crossover Frequency||Via Tun software|
|Low-Pass Slope (dB/octave)||Via Tun software|
|High-Pass Crossover Frequency||Via Tun software|
|High-Pass Slope (dB/octave)||Via Tun software|
|Bass Boost Frequency||N/A|
|Speaker Level Inputs||RCA|
|Preamp Outputs||1 pair|
|Parts Warranty||2 Years|
|Labor Warranty||2 Years|
Digital Signal Processing
VXi Amplifiers: The JL Audio VXi-series of amplifiers feature advanced technology with built-in digital signal processors. These compact amplifiers pack a lot of power into a small package. Each VXi amplifier is equipped with a customized, triple-core AKM DSP that allows you to tune the amplifier to the exact performance you need. With JL Audio’s free TüN software on your computer, tablet, or smartphone, you can configure the amplifier from the driver’s seat. Up to six active preset tunings can be stored.
4-channel Amplifier: The VX400/4i 4-channel Class D amplifier that has been optimized for full-range amplification of connected speakers. It has advanced NexD2 switching amplifier technology to deliver solid performance with high fidelity and efficiency. The amp does not have traditional control knobs and switches for setting up the amplifier. Instead, the input sensitivity, crossover, and polarity settings are configured via the TüN software.
Logo Badge: The included JL Audio logo badge is included in the box, unattached. The badge has an adhesive backing for attaching it according to your installation in any 90° increment. The color of the LED ring around the logo badge can be configured in the TüN software to display the amp’s status, audio preset, or a user-defined color.
Digital Signal Processing
AKM DSP: JL Audio’s AKM Digital Signal Processing engine, when partnered with the TüN software, gives you an enormous amount of control over the configuration and settings of the amplifier. It is equipped with high-performance AKM A/D and D/A converters, and audio processing for high-resolution 24-bit/96kHz audio files. For some VXi models, the DSP offers a 10-band parametric EQ for each output channel, including pre-outs, Linkwitz-Riley and Butterworth high-pass and low-pass filters, Signal Delay (0.01-millisecond steps), polarity reversal, and output trim levels (in 0.1dB steps).
TüN Software: The free TüN software lets you configure, tune, and control your VXi amplifier from your PC, tablet, or smartphone. The TüN software is available for Windows PC (Windows 7 SP1, 8.1, and 10 / 32-bit or 64-bit) and Apple computers. TüN Mobile is available for iPad and Android tablets, while TüN Express works with iPhone and Android smartphones. The apps are compatible with iOS version 10.0 or later, and Android 4.4 and up. When connected to the VX400/4i, you can make the following adjustments and settings on the application:
- Input Selection: Analog or Digital
- Turn-on Mode: Remote, DC offset, Signal Sense
- Input Mode: 2 Ch / 4 Ch
- Independent Settings for CH 1&2 and CH 3&4:
- Input Type: Stereo or Mono
- High Pass Filter: Off, 12dB, or 24dB; Cutoff frequency: 20Hz (or LPF frequency) to 20,000Hz
- Low-pass Filter: Off, 12dB, or 24dB; Cutoff frequency: 20Hz to 20,000Hz (or HPF frequency)
- Level Setting:
- Input Level: Min to 11
- Output Trim: -18.0dB to +12.0dB
- Mute All: On/Off
Power Output: The VX400/4i power specifications are as follows:
|Rated Continuous Power @ 14.4V
|4Ω||75 x 4|
|2Ω||100 x 4|
|4Ω bridged||200 x 2|
|Rated Continuous Power @ 12.5V
|4Ω||60 x 4|
|2Ω||90 x 4|
|4Ω bridged||180 x 2|
Power/Ground/Turn-On Terminals: The VX400/4i features a removable plug with C-Clamp terminals for the power, ground, and remote turn-on cables. This allows you to pre-connect the wires to the connector, then plug it into the amplifier. The power connector will accept up to 4-gauge power and ground wire, and 10-18-gauge wire for the remote turn-on. The supplied 3mm and 2.5mm hex wrenches are for tightening/loosening the C-Clamps.
Note: The amplifier is not equipped with a fuse. An external 40-amp AFS, AGU, or MAXI fuse (not included) must be installed on the power wire. If a wiring kit is used which includes a fuse with a value other than 40-amps, the original should be replaced with a 40-amp fuse.
Speaker Output Harness: The JL Audio VX400/4i features a removable ABCD Speaker Output Harness with 18″ wires.
Analog Input Harness: The amplifier has a 15-pin D-Sub connection for the supplied 14″ Analog Input harness. Four loom-covered cables exit the cable’s D-Sub connector, with two pairs of stereo female RCA inputs, stereo female RCA preamp outputs (4V max output), the remote turn-on output (+12V) and Valet Preset Toggle lead.
Digital Inputs/Outputs: The amp has optical digital (Toslink) inputs for direct connection of S/PDIF digital sources, bypassing the A/D converter. The input accepts up to 24-bit/192kHz signals. There is also a Toslink optical digital output for sending a digital signal (24-bit/96kHz) to another VXi amplifier.
USB: A Type B USB port is provided for connecting the amp to your computer for interfacing with the TüN software. A 6′ Type A to USB-B cable is provided.
RJ-45: Two RJ-45 modular ports are provided on the amplifier for optional accessories:
- JLid-COMM: One RJ-45 port, labeled JLid-COMM, is for the optional VXi-BTC Bluetooth Communicator (for wireless communication with Apple or Android smartphones and tablets), or the optional VXi-HUB Optical Network Hub (for connecting up to five slave VXi amplifiers — ten with two VXi-HUBs, allowing synchronization of controllers and DSP presets).
- JLid-CTRL: The other RJ-45 port, labeled JLid-CTRL, is for the optional Digital Remote Controller (DRC) connection. The optional DRC-205 digital remote control allows you to conveniently set amplifier levels and DSP presets from the front of the vehicle.
microSD: A microSD port is provided on the front of the amplifier for future expansion.
- Frequency Response: 12 Hz – 24 kHz (+0, -1dB)
- Input Voltage Range (at RCA inputs): 200mV – 16V RMS
- Signal-to-Noise Ratio:
- Analog Inputs (20Hz – 20kHz noise bandwidth): 99dB (rated power); 80dB (1 W)
- Digital Inputs (20Hz – 20kHz noise bandwidth): 101dB (rated power); 81dB (1 W)
- Damping Factor: >100dB / 50 Hz @ 4Ω; >50dB / 50 Hz @ 2Ω
- Standby Current Draw: 2.3 mA
- Dimensions (WxHxD): 9.02″ x 2.1″ x 6.686″
- Weight: 5.0 pounds