[George]

Serge,
Something's not right. You should have a small white block labeled
"Create Mono File For Karaoke" located just above the "Read Manual" box.

It sounds like you're using the sliders correctly, to the left reduces the low frequencies and to the right reduces the upper ranges(after clicking the appropriate box).

Responses vary from song to song, and mode to mode. Must be a stereo recording, and preferably one recorded with the vocal center panned at the studio. In the higher ranges, the frequency response of the speakers, and the hearing level of the operator play an important role. You can't work with what is not being heard. Don't take this wrong, I'm not making any assumptions regarding your hearing range or that of the speakers, but these are all variables.I've noticed on mine I have to be extra critical when working with the higher frequency slider than I have to with the low.

Perhaps sliding the "Output Amplitude" slider up might help hear the higher responses. This should be done anyway to compensate for decreased levels.

You might try messing around with some different material, and see if the results change. Sorry I've not been much help.

Take care,

George