When I'm testing or voicing a speaker I use several cds that I favor. In no particular order:
(Passion) , a sampler cd from Mercedes/AMG, quite possibly the finest cd recording to date in the world! The problem with this disc is that you have to buy the car to get it, not sold separately
Oh! That Cello, from First Impression Music. Simply wonderful.
Come Walk With Me, by the ARC Gospel Choir from Mapleshade. Great for Imaging and soundstage. Kevin Haskins of Exodus Audio also uses this one! This cd is the only Gospel music I own, but if it got damaged I'd be ordering another one the same day.
Great Opera Choruses-Wagner & Verdi from Chesky. Great for evaluating the sense of scale that a speaker (or system) can deliver. Good sounds as well.
I use a variety of others, but these are always on the list.
Best regards,
TerryO