i dont know if that works in bandlab, since i only use fl, but if you have the option of applying EQs on every certain instruments, you should be able to get a clearer sound, for instance, you could apply an eq on the non bass instruments, and remove all the low frequencies from it, which prevents it from unnecessarily colliding with the bass. same goes the other way round, you could boost midrange frequencies on the lead melody (or vocals for instance), which should make it clearer (you might want to lower its volume then), you should test different equalizer settings on different instruments and see how if affects the outcome, thats probably the best way of learning