Hello Ladies and germs (and my boo Wendy).
Well Eighty2Regal...there are so many ways to do this. I started a thread on here that involved me installing 2 18's in my trunk (84 Regal) for exactly what your looking for...ALOT OF QUAD AND TO BE SEEN! Just go find the thread and read it all. It will help alot. If your too damn lazy to do that, then just read this.
I couldn't take it anymore myself. I was trying to wait and do my mids and highs and they just weren't doing the trick. So I started to run 3 12's in one of those funky three chambered pre-fab boxes where the two chambers on the side are slanted back? I installed one in the middle...why you ask? Because the magnets on my subs hit the inside of the walls of my sub box on the slanted chanmbers.
Easy fix tho, Imma just buy a piece of .25 mdf and that will raise the subs up enought to be drilled in. Now with that one 12 inch that I have (Audiophonic ADF-272 600/1200); I mean yikes! The thing just quakes! I have a 94 amp alternator (that I had to replace real quick), a '05 Autotek MX1500.1, and thats it. Of course an old ass touchscreen that I don't even flip out because I dont like the features and I need a usb and aux jack on the front, three speakers (because I took one out to see why it was rattling and tore the paper and cone off of the frame beacuse I had nothing better to do), and a Kenwood 6042eq that...is...just...amazing!!!!! The sepration that I have with this thing is just incredible!!!
I haven't even begun to tear away the black plastic and insulation from my backseat, no dampening material (well some eggsell cushions from a local dealership that wasn't using it; sat that ontop of the box), no blow through the backseat to come out into the cabin. I want to tear away the cushion right...up...to the backseat for a more stealth look but then I thought the vinyl may give over time and with the pressure of the bass and air movement. So I'll think of something else to do...and no Im not making port holes through the 4x10 rear deck. For some reason to me, the sound is just different when coming through those holes and hitting the glass and roof...just doesnt seem like it would roll off right like would a hatchback or suv.
Now I do need to get a stiffening cap or just a stronger alternator, do the big three, and wire the sub down some more. I currently have it wired to 8 ohms...smh...yea I can't understand it either. 8 ohm load and it sounds ridiculous!!! My amp is 2 ohm stable and I have it bridged right now. I like to play real bass songs...not late night creep by 3 6 mafia (no offense tripple six)...no youtube video music...but I do like to play Busta Rhymes, Slim Thug, Paul Wall, Gucci Mane, Waka Flocka, Letice, Mary J. Blidge, Ludacris "Woozy", 8Bal & MJG "Whatchagonnado", Mystikal, Jill Scott, Scarface (Emeritus album...goodness), Too Short, Bun B, Pimp-C, Outkast, etc etc etc...
I play rap, Neo soul, R&B, Rock, jazz, and everything old and funk. The sub just doesnt stop. Now mind you after riding a while and just beating it to death...it will get muddy and thats because of the amp not getting the proper juice it needs to perform. Bass Thrust and gain are half way.
So maybe it will help if you get a bit more powerful amp, do the big three to your electrical system, and have a box built, or just change out the sub (preferably dual voicecoil subs) and you should be good to go! Get a good eq also...from a reputable company (Audiocontrol, Kenwood, Zed Audio, Zapco...trust me it'll be worth it!