Frank is right on the money here. Most cars post 1990 have speed signals (Vss) available all throughout the car.

Many cars have the Vss signal at the back of the OEM radio, at the ABS sensor, traction control, idle speed control, ECU, cruise control amplifier, etc. etc. The list goes on and on.

Virtually all cars generate a square wave Vss signal based on magnetic reactance sensors at the rear differential (for RWD cars anyway). Sometimes the raw signal is sent to the speedometer for processing and distribution to the res of the car.

It would be extremely easy to build hardware to decode the Vss signal and output it as an ASCII value for an RS-232 port. I could do the hardware in a few hours. But I have NO idea how you'd incorporate this into th Empeg.

In any case I would be interested in having this feature, as it is helpful to have speed sensitive volume.

-oktane