One unfortunate side effect of the increase in technology on automobiles is what has happened to engine sounds.


A combination of better cabin insulation, plus the increased prevalence of turbochargers and other high-tech gizmos, has made it harder hear modern engines. That an engine sounds too "mechanical" is a common complaint to see in reviews of even the best cars.

So automakers have gotten around this (kind of) by findings ways to pipe engine noise into the cabin. Last year Car and Driver had a great feature on how this works.


Lots of new cars use some method to enhance sound for the driver, including the Lexus LFA, the Mustang GT, the Volkswagen GTI, and several new BMWs including the M5.

One member of BimmerPost's 1Addicts.com forum named TMP discovered that his new M135i also uses a "sound symposer," which plays a pre-recorded engine sound through the stereo system. He found a way to disable it, and here's what he reported:

But that low bassy six cylinder thrum, all the way up to the banshee howl is gone from the cabin. Instead, there is a faint choked turbo six with the dump valve being the loudest thing. It's not nice and the car loses that character noise. Really noticeable from 2500 rpm. But really no reason to unplug the symposer device as it disables the car's audio system. This was done just for testing purposes.

He was kind enough to let us be the judge for ourselves. The top video is when it's been disconnected, and the bottom is when it's working normally:

I see now why BMW does this, but I think it's kind of sad that they (or anyone else) have to artificially improve the sound of the engine in any way.


What do you think of engine sounds being enhanced and piped in through speakers?

Hat tip to Declan!

Photo credit BMW