Honesty man I started this viscous Audio cycle when I was 16 and I'm now 19. I've had 4 systems in two cars in about a two years period. First one cheap ish entry level $20 hifonics in a slanted sealed box with a cheap American pro amp free from friend. I thought it was loud as crap yet crystal clear until I heard a louder system. The next one was 2 powerbass midlevel 15s large sealed box and a audiopipe 1500.1d. That second one was by far my most expensive system do to the fact I did the big 3 got a 280A alternator for a JAPANESE IMPORT, not cheap, and all that zero gauge. Left for college and sold it all. Got to college bought another system off someone else, mtx 12 5500s in a cheap ported prefab mtx box with earthquake amp got it all for $100 from another student. Totaled that car about 3 weeks later and sold it all to my roommate for $90. 8 or so months I was carless, got a car in September got a system in November, cheap insignia kit w/ night prefab ported box, off craigslist that I overpaid for because i didn't research, sounded decent but it wasn't enough sold it all 2 weeks ago bought and reconed an AB HD15 just bought a AB GOLD 150.1 today that I plan on attempting to repair.
I said this basically to say I don't think it's possible to be satisfied with the system you have forever so buy stuff, sell stuff, buy more stuff, try everything and maybe just maybe one day you'll find your perfect system or you'll have grown out of the hunt. So upgrade that alt and grab some batteries a go for really loud sound quality as it was mentioned earlier "you can always cut back the power, but you can only go up so high without distorting." It almost tax time so hold out and go hard. DIY is a big money saver.
Out of all those setups though I really loved my sealed ones especially my 15s whom I so deeply miss...tear. Sealed fairs well with all types of music. Truly enough my ported boxes were never tuned to their drivers, they didn't really like the lows. Everything below 50 to 45 sounded and felt really flat couldn't even feel it in my chest. Sealed to me does well on both ends of the low spectrum.
This is not professional advice but it is personal experience.
