Recording with bass to align my subs with my speakers

Upgraded my cables on my Rel S812 subs to the "Blue" line and Wow what an improvement this cable makes in the bass.  So much that I need to readjust the crossover and gain.  My dealer set up my Wilson Alexia's and REL S812's when I got them a few months ago but REL suggests turning the crossover up and to adjust the gain which is necessary as well.  I checked out the REL set up videos and I'd like to get a recording as a "go to" for now and future tweaks as needed.

Mostly listen to Jazz from the late 50's and 60's.  Some Rock and Classical as well.  Would like to find something that is on either Tidal, Quboz, or vinyl but a CD would work as well.  Lots of options out there for bass recording tests but am hoping to see if the group has landed on a "must have".

Appreciate the feedback.

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