View Single Post
      01-08-2019, 03:26 PM   #98
COKen
Lieutenant Colonel
COKen's Avatar
981
Rep
1,560
Posts

Drives: M Rster / Z4 M40i / X5 M50i
Join Date: Dec 2013
Location: Colorado

iTrader: (0)

Quote:
Originally Posted by Billfitz View Post
At what distance? SPL goes down by 6dB with each doubling of distance from the source, up by 6dB with each halving of distance. At what RPM? Idle, midrange or full throttle? Is that an A-weighted or C-weighted result? In the low frequencies there can be as much as a 50dB difference between the two. Your eardrums can be pounded into mush by low bass while an A-weighted meter won't even register it. These are just a few of the variables that make a simple statute unenforceable.
The chart I was quoting was (I think) using the standard of 50 feet and the motor running at normal cutting speed (high rpms). No real detail was given. Not sure if the CA law set some other standard or not, but 50 feet from the source is what should be used. Wind is another variable which can't be controlled in the open environments where cars operate.
__________________
2002 M Roadster, Steel Gray Metailic, Gray Nappa Leather, HT, TC Kline DA Shocks & Camber Plates, w/H&R Springs, Stromung Exhaust, SSR Type C. Looking for new home.
2022 Z4 M40i, Misano Blue Metallic, Driver Asst Pkg, Prem Pkg
2023 X5 M50i, Phytonic Blue, Black Extended Merion Leather, Driving Asst Pro Pkg, Park Asst Pkg, Exec Pkg, Climate Comfort Pkg.
Appreciate 0