Here is how I set up the filters on my 756 PROII, showing Frequency vs. Amplitude plots for both Sharp and Soft, but I prefer the Sharp. Input was white noise from 10 meter band, so not a perfect test. I switch MixW2 to use Filter 1 to look at all the signals in a 2.6Khz slice of the band, then Filter 3 for the QSO using macros that are part of my CQ, Reply, and Bye commands.

Filter 1, SSB Voice Medium, 0-2600 Sharp

Filter 1, SSB Voice Medium, 0-2600Soft