Modern cell telephone units stream their audio via Bluetooth link directly to vehicle's audio system. This leaves two very neatly-located dashboard speakers unused. Has anyone thought or heard of active noise canceling system that could utilize these two?
Technically, all that needs to happen is two 5-watt amps inverting ambient cabin signal (from microphones mounted, say at the top of each door post) 180 degrees out of phase and deliver it to these two speakers. An additional speed-dependent automatic gain control would sweeten the package, but the system is not really needed until you reach highway speeds & remain there for prolonged periods.
Technically, all that needs to happen is two 5-watt amps inverting ambient cabin signal (from microphones mounted, say at the top of each door post) 180 degrees out of phase and deliver it to these two speakers. An additional speed-dependent automatic gain control would sweeten the package, but the system is not really needed until you reach highway speeds & remain there for prolonged periods.
