Hello Tom,
I've noticed that the one-sixth octave project, though more effective at noise reduction, unfortunately imparts some audible artifacts. This is most noticeable in quiet passages in classical music, where the string section is slowly changing in volume. I can hear some channels cutting in and out in response to this changing level. That's from the ABCD Comparators used to control the frequency channels:
The result is the all-or-nothing decisions shown in the left graph below, resulting in the audible difficulty:
To avoid this, a proportional method can present intermediate values (not just 1 or 0) to the slew ext volume controls. This method, diagrammed below, provides the response shown above right:
The result sounds better to me. Adjustment is easier too -- instead of a dB-calibrated threshold control, there's simply a slider to adjust the proportional multiplier gain (GX). It operates opposite to the previous threshold control -- slide it higher for better-quality incoming audio.
BTW, SigmaStudio has a neat feature that allows nearly instant A-B comparisons between two entirely different projects, such as the last two iterations of this one. You'll find how to use this feature in the help.
Best Regards,
Bob