Ok, so I have a JVC head unit (20 W RMS X4) with stock speakers on an '05 Corolla (6 speaker model; 4 speakers, 2 "tweeters"). The speakers have '17.5 W' and '6 ohms' stamped on the magnet) and I'm guessing 17.5 is RMS (at least what I read online)? So the head unit has this feature:
"Amplifier...