Should be Ok, it is annoying but recoding should cut it by 90%
Should be ok with HiFi 2ohm woofers, find a set used...shouldnt need any more power than the base audio 6.5.
---just figure out if you are going to go trunk sub or not, if yes then get cheap used oem woofers from a hifi car, if no, then get sws8xi, and try it, amp later depending on taste.
Was just asking,...now that you have a normal calibration, i am less concerned. -20 should work for no amp configuration.