I have an h701 and am using two nine.1s for sub amps. The h701 lets me set the center out as a second subwoofer out, but I only used the sub out for the signal to my nine.1. I didn't use a Y adapter to connect both stereo inputs on the sub amp either. Is there any need to use a Y adapter?

Logically I am thinking that the sub amp has stereo input incase you dont have a sub out in your head unit. In which case it will just take the sub freq from both channels.

I have also head some tracks use stereo bass to create some weird harmonics or whatever. So if the alpine lets me have two sub outs, any advantage in running each out to one of the amps? or is this just a myth?