Level matching for a/b testing?

db meter, or app on your smartphone

https://www.dagogo.com/audio-by-van-alstine-abx-comparator-review-part-1-audio-store-wiring/

^^^^ is a very useful tool... but a little pricey 

@millercarbon I hope that the overwhelming majority of your other 8324 posts are less condescending and more instructive than this response. Otherwise, why do you bother?

Because now at least you are thinking about it, and maybe a little less likely to waste your time with meters and stuff like all the nice but ultimately less helpful people will say.

oldskoolmark OP

Use your phone with a dB level app in it.
Play a set "reduced level 1khz sine wave" so it’s at the same volume control position setting as where you normally listen at, note the positions for each of the pieces you want to a/b then play music on both at those volume positions.
https://youtu.be/PyD9cMarVJk

Cheers George

OP
Hoping won’t get ’er done.
Not ALL responses just plain old rude.
Only ~ 92% of ’em.

Try level matching at the source first if available.