These are not new speakers. I bought them about 2.5 years ago.
Originally one of the speakers had to be repaired by the dealer because of a high pitch whine - which apparently was a faulty board of some kind.
I'll contact my dealer if you think that's the best next course.
I'm also at a loss to figure out what is wrong here with my other settings.

I'm guessing they're broken (if so, sorry about that), the other repair was probably the amp module. Sounds like they need to have the input panel PCB's replaced, dealer should order the parts (they'll need the serial numbers of your speakers) and let you know when they're in... maybe they can do the service in your home to save you the pack and travel (job cab be done with the speakers in place as long as the back panel is accessible). Tell them you "can't turn the bass level down", that's all that's necessary to report this problem.