You can always rationalize a reason why the new one is different enough to make it nessidsary… I have closed back and open back headphones, but those are both dynamic drivers, so of course I need a planar… So you get some Sundaras, but maybe now I need a closed planar…

I have a no longer supported LG G7 with a SD car full of my music collection. It has enough Juice for all my headphones except for my Modified Fostex T20. To be honest, I haven’t used it much since I got my Qudelix 5k which I use with my functioning smart phone.

Well, you can use frequency response to tell you some things, like if they are bass/treble heavy or v-shaped response. After that when you have heard some things that reviewers have also done reviews for to gauge how much your own taste aligns with various reviewers.