I had thoughts about this. A question came to mind. Is the speaker you will be auditioning, Brand New? Some speakers, especially "high end" speakers suck right out of the box. Needing break-in time. Receive, Unbox, Setup and Listen maybe dreadful.
I have a cd compilation of "test" pieces I’ve used for years. Jazz, orchestral, solo vocal, solo piano... I may use vinyl if a thought comes to be, picky.
I can’t do quick A/B test listens. I prefer to set the new speakers exactly where my present speakers are. Needing just a bit of toe in/out, forward/backward. Subwoofer comes later.
A long listen for me. See how much of that or other "something" bugs me. I would not be looking for another speaker if something is not bugging me about my present speakers or system. Continuing down the audio rabbit hole.