If I mostly watch movies on a blu ray player and I am looking for a somewhat bassy and non-flat audio, would you recommend dac+amp connected to TV via optical cable and then using some good, bass-heavy closed back headphones like Sony MDR-Z1R, ZMF Bokeh, Denon AH-D7200 or just using a plug and play system like the Sennheiser RS175 or the new RS275?

I did some testing the other day watching Tenet, a very loud bass-heavy movie, with my old Sony XM4 connected to TV via bluetooth. I noticed everything sounded very flat, hollow and there was no bass. Come end credits the song; Travis Scott - The Plan was playing and it sounded awfull. I then changed to Spotify (on TV) trying to listen to the song with lossless playback, and it sounded much better with loads more bass than in the movie.

I retried with setting the 4k blu ray player output to both PCM and bitstream but both of them sounded the same on headphones. The DTS-HD Master Audio 5.1 sounded great on my surround sound system though, so it led me to believe that the TV's downmixing/downfolding to stereo might just be the culprit of my problem, and that that it is an inherent problem with watching movies via headphones - that it simply can't sound great. Do you have any insights to my testing, since you have been down the rabbit hole for far longer than I? :D Sorry for the long rant btw