Relating to Area P and sound levels - Information noted below on our C-14 website page to assist
SOUND
The sound readings are taken statically using the standard 20" test at 45°. Slip-On exhaust tone is very different, though the actual decibel levels are very similar. Very low frequency.
Full System - An all gear cruising and to the soft limiter sound byte is noted below. Exhaust tone is very deep, low frequency. Sounds awesome. Muffler is positioned slightly under the bag to assist deflection and attenuation of sound.
Idle 5000rpm
Stock 77-78 dbA 92-93 dbA
Slip-On 83-84 dbA 92-93 dbA
Full System 86 - 87 dbA 98 - 99 dbA
We utilize one of the higher end Extech models (there are a lot of them) and Calibrator to log Sound level data that is fairly accurate and repeatable. For consistency, all tests are done in the same location, same person, and as closely as possible - same overall environmental conditions. Less expensive meters will provide a lot of fluctuation, as do the surroundings and parameters which you are testing. We've seen many less expensive (even more expensive if they are not consistently tested for calibration) have +/- factors of 2 - 5 dbA. In our world, that is a huge difference! Ambient noise from other sources, how you test, where you test, meter accuracy, etc, etc, are all important for consistency. Loose body work, levers, the mileage it has (high or low), even an aftermarket air filter will/can make a difference. We've seen completely stock, brand new bikes test +/- 2 dbA under the most anal of testing conditions. Sound pressure/levels/frequencies can be perceived very differently by each person. Quiet to one, is loud to another (and vice/versa). It is very subjective.