CD’s (lp’s are subject to any possible/minor alignment errors, a particular cartridge’s sound). (turn your ac system off).
Vocals: I listen at home; take these CDs to Showrooms; then listen again at home.
There are dynamic portions, but I want to hear Richard Burton’s voice. It is easy to ’know’ if it is ’off’.
https://en.wikipedia.org/wiki/Jeff_Wayne%27s_Musical_Version_of_The_War_of_the_Worlds
Next, Barbra Streisand/Donna Summers Duet: No More Tears. The similarities and subtle differences of their voices is amazingly revealing.
https://www.discogs.com/release/494873-Barbra-Streisand-Donna-Summer-No-More-Tears-Enough-Is-Enough
Next, my beloved Cassandra Wilson, her voice better be ’right’.
Eurythmics, Sweet Dreams: lots going on, sparkling highs and fading footsteps, channel separation, and again her voice better be right.
Dynamics/Range/Extension: this can be a trap, accurate may not be best for your ears/room/pleasure. One way to be objective is to play test CD, and measure/document with a SPL meter rather than your ears. Test CD, at listening position, ear level. Make a chart, write results down.
Amazing Bytes Test Tones, tracks 9 to 38
https://www.discogs.com/release/7290000-Various-Amazing-Bytes
there are others, luckily I got this when it was free, expensive now.
Extension: same thing, it can be a trap, more might not be best.
My JSE Infinite Slope Model II were always impressive at shows, finally got a pair, they were the most accurate speakers I ever owned (my friend has them now, restored). Joseph Audio uses some of the original Modafferri patents now)
https://www.audioclassics.com/mods
But, after a while I missed the sound of my less accurate vintage 4 way horns, with L-Pads to adjust for/in the room and for your particular preferences. (hard to get right, but when you do ,,,)
Canons ....boom, but balanced to other frequencies?