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      09-25-2013, 12:40 PM   #1
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Drives: F80 M3
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Post BMW M3 M4 Active Sound: the Good and the Bad News

BMW M3/M4 Active Sound... We Have Good and Bad News

We have both good and bad news on Active Sound technology in the M3/M4. For those unfamiliar, Active Sound technology was first introduced in the M5/M6 and has extended to other models such as the M135i. The system reproduces the engine's sound through the car's audio system at varying sound levels based on throttle input, speed, and engine revs, as well driving the mode (louder in Sport and Sport+ settings). See BMW's original press release on this.

BMW Press Release

Active Sound Design delivers precise feedback.

M5 drivers will be given an even more direct reminder of their car’s performance capability by technology that brings the distinctive sound of the high-performance V8 – in all its glory – into the cabin of the new BMW M5. The Active Sound Design technology specially developed for the new BMW M5 takes its cues from the driving situation at any one time to deliver an accurate reproduction of the engine’s sound through the car’s audio system. The system’s digital signal processing exchanges data directly with the engine management, allowing it to reflect the engine’s revs and torque, and the car’s speed over the road. The result over a smoothly driven journey is a discreet soundtrack in keeping with the harmonious and assured characteristics of the V8 powerplant. A stamp on the accelerator, meanwhile, prompts an immediate audible response to match the instantaneous – and typically M – burst of power from beneath the bonnet.

In generating its signals, Active Sound Design takes its cues from the firing sequence of the eight-cylinder engine and the frequency range of the exhaust system. This gives the driver an extremely accurate impression of current engine load and an even more intense sensation of the V8’s high-performance characteristics. At the same time the Active Sound Design control unit ensures an even spread of sound across all five seats of the new BMW M5, while observing the legal guidelines governing noise emissions inside and outside the car. The characteristics of the sound produced by the technology also adjust to the engine settings selected by the driver. For example, switching to “Sport” or “Sport+” mode sharpens not only the engine’s responsiveness but also the acoustic experience inside the car.

So, the bad news is yes, the M3/M4 does feature Active Sound.

But, the good news is that we've confirmed with BMW Germany that it's a live amplification of the S55 engine's natural sounds. There is no artificially generated sound or pre-recorded track being played. This sound amplification takes place through the M3/M4/s stereo speakers.

Those with thoughts of disabling the amplification may be disappointed to learn that since the sound is played through the audio system, past attempts by M5 and M135i owners to disable Active Sound required pulling the stereo system fuse or unplugging a Sound Symposer unit. While the Active Sound feature was disabled with both methods, so were the entire audio systems. See the video below by BIMMERPOST members for a sample of how the M5 and M135i sound with Active Sound disabled.

Separately, we tried to get clarification on whether the manual transmission's rev matching feature could be disabled. BMW remains mum on the topic, for now.

How the M3/M4 sounds inside the cabin.

Audio system fuse pull on F10 M5.

Sound Symposer unit unplugged on M135i.

Compared to the normal sound.