View Full Version : Ambience compensation device...

09-07-2003, 12:42 PM
Just curious as to whether or not this has been done. I'm trying to think of "new" things to add in to my system, and was considering an amibience compensation thingy. I don't know what they're called, but it's basically a device that increases volume when the ambient noise of the vehicle increases. Thus, the percieved volume remains constant. Anyone ever made anything like that?

Anyway, I'm pretty good with embedded systems, though I've never worked with digital signal processing... so, what I was considering was mounting a microphone just below the front center of the floorpan (just behind the engine compartment) to measure the level of noise outside the car. While it won't be exact, since that location will read a pretty good mix of wind, engine, and road noise, it should be very close to proportional to the volume inside the car. Anyway, I would then simply monitor the volume level on that mic, and I would have a variable resistance on the RCA lines; this resistance would be reduced as volume increases. Since it's mounted outside the car, I wouldn't need to do any DSP functions to filter out the stereo portion of the noise.

Anyway, anyone else ever done something like this? Either way, does it sound like a good idea? I'm really brainstorming for something to set my system apart, you know :)

09-11-2003, 07:42 PM
BMW has something to that effect in the Z4... when you exceed 60mph, it gets louder, then quiets down again when you drop below... I'm sure it's actually connected with the speed rather than the actual noise levels tho.

09-17-2003, 08:29 PM
Actually my JVC El Kameleon II LX-50 has voice recognition and also has this feature built in, as the noise inside the car rises, it automatically adjusts volume. I know this doesn't help, but just wanted to let you know, there are CD-Players that do have that function.

Boomin Granny
10-08-2003, 05:39 PM
My Pionner DEH-P7500MP does this as well. And although I wish you luck on this since it is a very bold idea. It isn't as cool as it sounds, When I put the sensisitvity on mine all the way up, it would get dramatically louder whenever I would even talk or light up a cigarette. I think just adjusting the volume as the noise gets louder works best,

Boomin Granny
10-08-2003, 05:40 PM
I didn't mean your idea wan't cool. I meant the actual process of the hu adjusting volume based on road noise isnt that cool.