Quote:
Originally Posted by GLD
I do not understand how such things can be used interchangeably

6/ln(2) and 20/ln(10) are actually change of base formulas, allowing you to use exp() and log() (actually natural log) functions.
Proof:
10^(x/20) and 20*log10(x) are the scientific standard, unfortunately. I feel like this is slightly at odds with common sense in audio. 6dB=2.0 feels more intuitive compared to 20dB=10.0, but I have run into problems before using base 2 and have stuck with base 10 since. Almost everyone, including Reaper internally, seem to use base 10.