BMW z4 electronic engine sound enhancement

[randombloke]

Just came across this:

http://www.autoexpress.co.uk/carrevi...sdrive28i.html

But for the Z4, BMW has included an electronic sound generator, which augments the bass and baritone at idle and in the sweet spot between 2,500-3,500rpm. OK, so this four-cylinder version doesn’t provide the smoothness or audible thrills of the six-cylinder sDrive30i, but as the efficiency gains are so impressive, it’s an acceptable compromise.

reminded me of this old thread:

plug in rev-matched v8/v10 sound generator

[desperado]

I believe the Audi TT includes some sort of port which ducts intake sound into the cabin to "enhance" the driving experience.