I just upgraded the speakers/sound in my ST:TNG and documented it here:
https://pinside.com/pinball/forum/topic/improving-sound-quality-the-diy-route/page/19#post-7092703
I have parts to repeat the process with my TZ, but I want to experiment with Pinsound on my ST:TNG first, then give a listen to the TZ orchestrations, before committing to that path with my TZ