the 20.1 will run daily @ .5 nominal with no electrical upgrades.. and depending on actual impedence... do 1600-2100 watts
at .5 nominal, efficiency is around 68-70%..
with upgrading wiring, and 2 big batteries.. you'll be able to maintain 12v pretty easily, even with demanding content..
near 12volts with plenty of current.. 20.1 will do between 2400-3kw @ .5 nominal, again depending on actual impedence..
in my car during our little test session, I measured burst current demands of over 320 amps with a couple different bass heavy tracks @ 12volts..
with a sine wave.. 317 amps of continous draw at 11.7 volts ( car wasn't running, and the amp was in use for over 3 hours before power testing //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif )
Loyd L.