Songs for Speaker Placement

This is a helpful diagnostic tool:  https://www.audiocheck.net/audiotests_ledr.php  The LEDR test is also available on some system set-up CDs, but-  the phase anomalies, present in some CDPs, can affect the results, as explained in this Stereophile article:     https://www.stereophile.com/features/772/index.html

@audionoobie, At least this is what I experience too. I am also experimenting a lot here... 

PS Audio founder Paul McGowan explains midbass in his youtube video titled "Optimal distance Between loudspeakers". I also find different listening distance from speakers affects bass as well. Bass null zones as they call it. You can hear more about it in a Youtube video by Dynaudio titled "A Master class in speaker placement" 1:56 distance to the wall.

Hope this helps.

'Depth of Image' by Opus 3 is IMHO the best recording I've ever heard in reproducing depth of image. It is on LP or CD and may be hard to find now. But I have heard it on a modest system carefully set up and it was so holographic as to be almost spooky. I used it for years setting up my own systems. The hard part was, having heard it perfectly executed, finding excuses for not getting my system to perform as well. :-)_

One caveat to using recorded music, as a metric for speaker placement: unless you receive a soundstage/voice placement map(with the recording), were at the performance, or actually recorded the event, you have no way of knowing if your system is recreating it accurately (no reference) .    With the LEDR, you can accurately pinpoint from where your sounds should emanate(no guesswork).