O.K. Wind Chaser was asking about the sound difference between the regular binding posts and the tube connectors after the upgrade. I'm not a professional reviewer but I will give you my listening impressions. First off, I didn't want to disassemble the speaker cables I already had which are 10 gauge Belden Brilliance with spade connectors so I soldered the male ends of the tube connectors to plain ole 16 gauge speaker wire I had laying around. I attempted to insert the tube connectors into the stock binding posts of the 600M's but they don't fit all that great. I was only able to get the very tip inserted ( I know what you're thinking) but it was enough to get a good connection. I listened to everything from Pink Floyd to Tracy Chapman switching back and forth between the regular binding posts and the tube connectors. Both sound good...but here is the difference. Imagine listening to a speaker and thinking, hey, that sounds pretty good. Then imagine someone taking off a thin veil from the speakers you were listening to and all of a sudden the speaker opens up even more. The speaker is more dynamic sounding. Highs are cleaner and slightly more detailed with more air. Vocals are a little more natural and open, bass is more dynamic. That's what the tube connectors do. Best example I can give. I was listening to "Liberty" by Annette USCG on Tidal. There is so much going on in this song. Little background sound effects, sharp piano key strikes, some smooth, jazzy saxophone, beautiful vocals. All sound just that much more detailed with the tube connectors.