Welcome to our forum.
Rich does your remote control your sound system inside of your house? I am not familiar with HS system, but the dolphin relies on a kind of signal reflector device to send the IR signal from your system to the remote, I believe as an RF signal (help Mendo...isn't that right?). If that is your problem, I may be able to help.
Why are you on the third one? Do they work and then fail? My little remote that controls the jets and lights failed, .there were several on here that had the same problem..but we figured out that we shouldn't have left them inside of the tub when we weren't using them. The bad thing is that since I take mine in the house now, I forget to bring it back into the tub... Have you had any feedback from anyone else on here about experiences with the same remote that you have?
Who makes it for Hot Springs? It isn't Balboa, right?