Speakers, speaker cables or I’m getting old…

My experiece has been that s the system gets better, the louder I can go without the harshness. This includes speaker cables, IC, and AC cables. A system is no better than its weakest link. Everything has impact IMO. Another plus is that recording that were unlistenable became more listenable. There's still good, better, best but few unlistenable. But I'm working on it.

I have had some similar experience as it relates to speaker cables and with Metallica, Tool and such on Qobuz.

• Speaker cables:  I owned a pair of Rocket 33s, Blue Jean Cables and borrowed a friends Kimber Kable 12TCs.  The Blue Jean Cables didn't have the clarity and separation in the low frequencies of the others and for some music the Kimbers were harsh and reminded me of why I don't have B&W speakers.  Ultimately I went to Kimber Bifocals and the sound singificantly improved to my ears.
• Qobuz:  When I upgraded from Bluesound node I tried the trial for Tidal and Qobuz.  I created a playlist and one day while grilling, a friend and I listened and randomly switched the streaming services.  I noticed two things - I appreciated the sonics of Tidal for some specific recordings such as Metallica, Tool, Boston, etc.  I also noted a few songs I wanted to hear were on Tidal.  

My last comment is as I've upgraded my system I have noted the playing db - and as my system improved the 'spaces of silence' between the notes are more drastic.  I used to listen at 85 db frequently because I thought it sounded better and I enjoyed the feeling of loudness.  No I notice 85 db doesn't seem as loud and I can have a conversation without raising my voice and sometimes I end up listening to music in th mid 60s and 70 db range. 

I initially thought this was driven by the increase in signal strength of a balanced cable.  I know think its the improved signal quality to the amp and the improved control on the speakers resulting in less noise between notes.  And I still could be wrong 😐

You're just experiencing something very important that cable deniers seem happily unaware of -which says a lot about their ears and / or systems-: the wrong cable can seriously bottleneck even the best system.

Yes, speaker cables can sound thin and bright and smeared. Nothing new here.

Mind you, I've been struggling in vain against a rather artificial / bright upper midrange for a while, blaming in turns my DIY speakers imperfect crossover or my room's imperfect acoustics, only to accidentally solve the issue by replacing the silver plated copper power cord on my preamp with a full copper one.

The audio chain is only as strong as its' weakest link.

While I wouldn't say cables are a tone control, they certainly have a bearing on the overall projected sound.

If you have nice gear, crappy cables can stand out like a sore thumb.