Heineken's Garage

The audio system of the Honda NSX consists of a center dash radio with three Bose active speakers and an optional CD-changer in the trunk. Even though the CD-changer was an option, the required cables were always installed.

JDM RHD Interior

The CD-changer's proprietary Alpine protocol (MBUS) was used across many Honda vehicles from 1991 to 2005. The company GROM (and others) have reverse-engineered it and are providing various options to add Bluetooth, MP3, phone, AUX and USB storage support to compatible radios.

The CD-changer connector (rightmost)

The connecting cable is made out of two parts. The first half runs from the radio to the area behind the seats, the second half the remaining way into the trunk. It's therefore possible to add such CD-changer replacement devices directly to the radio, to the area behind the seats or into the trunk. Depending on the intended use case, each one can be of interest.

For a simple AUX-in device (like the GROM MBUSDA1) connecting it to the back of the radio is probably the best option. For Bluetooth enabled devices without a microphone the area behind the seats might be a good choice.

GROM MBUSDA1 AUX-in

Same as the CD-changer, the devices are powered by the radio. Depending on the type of device, the CD-changer control buttons on the radio can be used to control the connected unit to a various degree. After connecting it, simply pressing the AM/FM button on the radio until the CD-changer controls light up is sufficient.

GROM AUX-in connected and activated

The resulting audio quality is clearly surpassing Cassette deck or even radio usage and can be considered a true upgrade in terms of audio quality while keeping the center console, radio and speakers in stock condition.

Please note that cheap, so-called "Alpine Adapter Cables" can't be used as the radio keeps an active two-way communication to the CD-changer, including error handling and notification. A simple "re-wiring" is insufficient (the radio won't even go into CD-changer mode).

Note: Europe specification radios can be electrically overloaded under certain conditions when connecting a specific adapter unit called "PA11-HON". Kaz knows how to reinforce the power supply to the CD changer port.