[swamp2]

Wow, this is by far the most detailed of this series of articles. Thank to M4post.com and to Herr Drees. Having worked for many years in the field of vibro-acoustics, I'm really impressed that BMW M is willing to share so much detailed information. Unfortunately there is just no way around (pretty much as discussed) the fact that normally aspirated sound >> turbo sound.

This has also slightly altered my stance on their using electronics (stereo system) to pipe noise into the vehicle. Knowing exactly what the engine is doing (state of load and engine speed) through acoustics only is an important part of driver awareness and can directly impact driving decisions. If this is improved through this technique it makes the system a bit more purposeful and less "oh let's just supplement the poor turbo sound".