Which freq. for the back speakers?

[joecool]

I have a rockford power 551x amp with an internal crossover and 4 channel wiring. I dont know if I should just leave low frequencies to the back speakers (2 way infinity kappas) or keep all signals passing into the 2 ways. I wanna hear clear lows.

[nda0602v6]

It would be kind of a waste to use a coaxial speaker and only send low frequencies to them. I would only send mid/high frequencies to them and get a sub to put out your "clear lows."