For the most part (generality), Rhodium seems to sound like a loudness button was pushed. More top end cleanliness and extension, and tighter and louder bass. The mids seem to retract a wee bit.
Again, very general impression based on 4-5 rhodium plugs I've heard and tested vs standard copper or gold plated copper/brass.
Again, very general impression based on 4-5 rhodium plugs I've heard and tested vs standard copper or gold plated copper/brass.