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As to the diagnosing tech.....not so much!
UPDATE - PROBLEM RESOLVED??!!This morning, the rain let up a bit so I got into the tub for a soak and started messing with the SpAudio system. I changed the CD in the player and, BOOM! The problems are gone. Both transducers are playing normally. No rumble! I let it play for about an hour and swapped out a couple of other CD's without a problem. I've never seen this before, but maybe the CD in the player just went bad. It was a CD-R burned with my favorites so it's been in the player all winter (including three blizzards). Man, I hope this was the problem! If so, my faith in HotSpring has been restored. As to the diagnosing tech.....not so much! On the upside, I now know more about the internal workings of a SpAudio II system than I ever wanted to know.Thanks to everyone who responded to my distress call!Fingers crossed....Rich