After spending far more time than planned reading and asking questions about Crossfire audio, I plan to buy a pair of Pyle PLPW6D 6-Inch 600 Watt Dual 4 Ohm Subwoofer from Amazon (Pyle-PLPW6D-6-Inch-Subwoofer) for $13 each, as it seems better to replace OEM subwoofers with subwoofers rather than 2-way speakers.

I considered fixing the subwoofers with the surround repair kit for about the same cost, but the original speakers are now over 13 years old and it just seems better to replace them.

I want plug and play. I don’t need or want to spend time rewiring and/or replacing the amp. I just want audio from a variety of sources, including some critical ones not supported by the OEM Infinity head unit, and all six speakers to work.

Although I had read quite a bit on the Forum’s audio section, after getting onehundred80’s feedback I went back and read some more. Much to my amazement I learned that the seemingly straightforward feeding of head unit channels into the amp does not work as one would infer from the Service Manual’s wiring diagrams.

Specifically, the post new-radio-head-unit-wired-factory-stock-amp-amplifier in which the AlpinetoCrossfireexanple diagram provided the fascinating detail that the
Not sure why it’s labeled Alpine; I recall that my Infinity unit had a Becker label. Will check again later after I get home.

I will report back after replacing the speakers, though that might not be until January. I am curious whether any of the Kenwood's subwoofer filter settings will be needed or make a difference.