just read this and i dont know if its been posted.. from yahoo
http://l1.yimg.com/bt/api/res/1.2/Q9...jpg_184920.jpg
Anyone who's heard aFerrari V-8 at full wail knows perfectly well that engines make music. But today, that vroom-vroom is getting harder to hear, thanks in equal parts to turbochargers that muffle the noise, increasingly insulated cabins, and government noise regulations.
Automakers are well aware that a snarly engine note enhances the behind-the-wheel experience—especially for sporty cars—and all sorts of devices have been used to let in this "good" noise. The Chevrolet Corvette's exhaust system has a valve that opens under full throttle and bypasses the muffler. The Porsche Cayman and the Ford Mustang both have "noise pipes" that connect the intake system to the cabin. These passive systems, however, are slowly being replaced with active systems that play a prerecorded track through speakers.
Case in point: Volkwagen's GTI used to have a noise pipe, but when the latest version appeared in 2011, the pipe was replaced with the Soundaktor. This system uses a hockey-puck-size speaker mounted on the firewall to generate extra noise. VW didn't exactly advertise the feature, and when word got out, the forums lit up.
"The Soundaktor is only there to lie to me," fumed one GTI owner on vwvortex.com when he found out his car has the system. "It's false advertising, plain and simple."
Andrew Wong is a 29-year-old engineer from Detroit. When he learned that his 2011 GTI had the Soundaktor, he simply removed it. Now he relies on an aftermarket exhaust system for better noise. "I want to hear the engine, rather than some version of the engine being played to me," he says.
VW is not alone. The new BMW M5, which ditched the sonorous V-10 for a twin-turbo V-8, plays an engine soundtrack through the car's audio system. From a carmaker's perspective, these active sound generators have definite benefits over a sound pipe: There's no need to cut a hole in the firewall or package a separate tube in the already crowded engine bay. Plus, the active devices allow a far greater degree of tunability and can be used to mask unwanted noise.
It remains to be seen just how far automakers will take these systems, but in the future, you may be able to toggle a switch that makes your Prius howl like it's got a V-8.
