Speakers will always make the biggest change in sound. Things like cables, very minuscule with some exceptions.
Best Stereo Upgrade Value
A question for you audiophiles...
What "upgrade/change" has singularly given you the biggest (not incremental) improvement to your stereo system? Upgraded amp, pre-amp, tubes, room correction unit, subs, connectors, cables, speakers, streamer, stylus, speaker placement, acoustic panels, etc.?