The 901 Series VI was never much for bass imho.
They sound absolutely great though as mid/highs with anything lower than ~500 hz is removed from their signal.
Though I AM a bit of an uncouth barbarian.... I use the heck out of a separate eq also, just leave the bose eq centered and adjust tone control with either receiver bass/treble (mid if it has it) or separate eq.
Don’t forget placement either, big difference depending on where they are placed.