JL AUDIO MAX (01) PDF Document

The High-Level Inputs on the JL AUDIO MAX™ are used for probing speaker level signals from the source unit and amplifier outputs. They are safe for probing Class D outputs. The technical notes indicate they are fully differential inputs accepting up to 80 volts AC peak (pins 2 or 3 to GND) and are safe up to 50 volts DC to GND. They use full size XLR jacks.

The Microphone Inputs on the JL AUDIO MAX™ are used with JL AUDIO MAX™ microphones only to acquire acoustical data. The technical notes specify a Max SPL of 133 dB (710mV) = 0 dBFS and a Mic Sensitivity of 7.6 mV/Pa. They use mini XLR jacks.

The Reference Input on the JL AUDIO MAX™ is for the connection of an external analog reference signal to measure transfer function. It is disabled by default in favor of the internal loopback reference. It is a differential input that accepts up to 7 V (peak) and uses an RCA-type jack.

The DAC Outputs on the JL AUDIO MAX™ can be used to pass any computer-sourced audio signals via the MAX’s onboard DAC (Digital-to-Analog Converter). These are 2-channel unbalanced outputs providing 4 Vrms @ 0 dBFS via RCA-type jacks.

The Monitor Out on the JL AUDIO MAX™ can be used to monitor the audio signals present at High-Level Inputs 1 & 2. It features greater than 60 dB of adjustable level control via TüN™ software and uses a 1/4 inch (6.35 mm) TRS headphone jack. The TRS connections are specified as T = Speaker +, R = Speaker -, and S = N/A.

Impedance Measurement on the JL AUDIO MAX™ is used for measurement of speaker impedance using TüN™ software. The user should connect the speaker as shown in the diagram provided in the PDF, where T = Speaker +, R = Speaker -, and S = N/A.

The Digital I/O Input on the JL AUDIO MAX™ is for the connection of compatible digital audio signals from a source. It accepts Linear PCM, 2.0-channel S/PDIF digital audio signals with sample rates up to 192kHz using a Toslink optical connection.

The Digital I/O Output on the JL AUDIO MAX™ is for the output of digital audio signals generated by TüN™ Software. The signals are the same as those output from the DAC outputs. It outputs Linear PCM, 2.0-channel S/PDIF signals from TüN™ with sample rates up to 96kHz. The hardware limit is 192 kHz. It uses a Toslink optical connection.

The USB Hub on the JL AUDIO MAX™ allows connection of VXi/MVi amplifiers or computer peripherals sharing the MAX’s main USB connection to the computer. It provides up to 500 mA to power computer peripherals, but it is NOT intended for charging mobile devices. It features dual USB A ports.

The JL AUDIO MAX™ connects to a Windows® PC or Apple® computer for control using TüN™ Software via a USB Type B connector.

The LED indicator on the JL AUDIO MAX™ indicates the status of USB communication with the host computer and TüN™ software. The statuses are as follows:

Off: no connection with a host computer

Green: connected to host computer

Blue/Green: communicating with TüN software

The USB LED alternates Green/Blue to indicate active communication with TüN™ Software.

The connection to the audio system ground or vehicle chassis ground on the JL AUDIO MAX™ is optional and should be used when needed to reduce potential noise between the audio system and MAX™/TÜN™ measurements.

To reset the JL AUDIO MAX™ hardware to factory default settings, press and hold Button A for seven seconds. The USB LED will illuminate Pink for one second.

To enter Device Firmware Upgrade (DFU) Mode on the JL AUDIO MAX™, press buttons A and B simultaneously, then release.

Pressing and releasing Button B once on the JL AUDIO MAX™ reboots the device. This action is equivalent to an on/off power cycle.

The JL AUDIO MAX™ uses a DC power input jack. The operating voltage is 12 VDC, which is typically 1A, but can be up to 2A with peripherals connected to the USB Hub. The power switch LED is Green when ON (I) and Blue when OFF (O).

When the power switch is pressed and released on the JL AUDIO MAX™, the power switch LED changes from Green to Blue.

The recommended microphone arrangement for spatial averaging with the JL AUDIO MAX™ Microphone Array places the Reference Mic (red) in the center position.

The JL AUDIO MAX™ Microphone Array can be mounted on a stand by accepting 5/8″-27 male threads. The stand itself is not included.

For optional stand mounting with an offset on the JL AUDIO MAX™ Microphone Array, it accepts 5/8″-27 and 1/4″-20 male threads. The stand itself is not included.

The components included with the JL AUDIO MAX™ system related to the Microphone Array are:

Microphone Array

Microphone Holder Assemblies (5)

Microphone Array Bar

Microphone Array Extension

MAX™ Measurement Microphones (5)

Microphone Calibration Adaptor

Microphone Array Extension Thumbscrew (Accepts 5/8″-27 and 1/4″-20 male threads)

Extra Washers (5)

Foam Microphone Tips (5)