Speaker hook up

[supertruck]

New to the forum. I have a decent indoor system but have a problem with my garage setup. I had an older JVC CD/Radio setup into a pair of Athena speakers. The CD stopped working so I found an older Sony setup (MHC-GX99) that I hoped to use with the Athenas, which I love. Here's the issue. The Sony has 4 speaker outputs for each speaker - plus and minus for the high frequency and plus and minus for the low frequency. Since the Athenas only have the standard two wire setup, I figured I could solder the two plus wires together and the two minus wires together from each speaker connection and tie them to my Athenas. No can do. The unit turns on but as soon as I push the CD button, I hear a click and the power indicator light begins flashing and nothing else works. I have to unplug the unit to reset it. Works fine with the speakers that came with it, but they have the 4-wire hookup. Did connecting the two separate plus and minus wires somehow overload the system? Any suggestions appreciated.