Speed Sensitive Volume Control

I'm embarking on a project that will take a line level audio signal and adjust the volume based on the level of a tach signal from a boat engine. (I want Arduino to turn the volume down when the boat is at idle and restore volume when running at speed)

I'm looking for a digital POT or something similar that will allow me to adjust the volume from code but, will not degrade the quality of the signal or add noise to the line. Most of the reviews I read on the digital POTs seem to indicate this is a problem.

Thanks!

You can use an I2C three band tone control and 4 input channel stereo mixer - TDA7439 if you can get on these days. Down load the data sheet for how to use it.

A digital pot shouldn't degrade the sound... if you use it properly.

I'm embarking on a project that will take a line level audio signal and adjust the volume based on the level of a tach signal from a boat engine.

If the tach signal is a varying voltage (not a varying frequency) you can use a VCA (voltage controlled amplifier) and you won't need a microcontroller.

the signal should not go through the pot.
the pot should control the amp.
if you control the right things, ou should not have any degradaton.