I currently have 4 12" MTX Terminators powered by a Hifonics BE35 1200.1D at [email protected] I know the MTX Terminators are budget entry subwoofers and I bought them before I knew any better. I'd like to upgrade my subwoofers to either 2 better quality 12" or a single 15" hopefully using the same 1200w amp I currently have. They're going in a 2015 Ford Focus SE Sedan. I don't know anyone around here with decent car audio so I have nothing to compare to and get a better idea. I was looking at some Sundown Audio or Skar but I'm not sure how much of a SPL upgrade they will be over my current MTX setup. Someone on Reddit said even upgrading to better quality subwoofers might not be a sound upgrade due to loss of overall cone area. Not sure where to go. Any help is appreciated.