more research is needed, if your after nice sounding bass that can get loud i'd prob be looking at a single 12"with a ton of pwr (custom box is a must) you can have the best gear in the world but if the install is crap. it will sound crap

Yeah 12 sounds nice. But I have to be unique. It's just my style. So a 12 Evan with massive power. Will be the same old same old. Yo dude that stereo sounds sick. What u packing. I got a 12. With massive power. It's just to generic. .. now when I say it packing 2 15s at 2400 watts. That has a little more ring to it. You know. But I'm stuck trying to figure out if the box that fits 2 15s would work in the small trunk I got to work with. I need it to

everyone that gets loud, has 15"s 18"s ect ect... I run a DD 9510G 10"sub and it's great when people think it's two 15's to see me open the boot and show them a single 10".... putting there big sub systems to shame.

unless ya after big air movement and hairtrick ect ect... in that case 15's are prob the go. what car is it? does it have a fold down seat or is it seal off from the boot?

Sounds like you are very confused and calling something a dream system without having a direction. A dream system to me would be a high end system with a great source (like a good quality head unit or factory unit with a DSP for tuning flexibility) Add some high end components like Focal K2P or Hertz Mille or higher and some Audison or Hertz amps and then finish it up with bass. In this dream system everything plays well blends together with lots of detail and sound that is pure and natural.

Or just get a bunch of subs with a ported box built to specifications and and a bigass amp and let your car rattle and be heard from miles away. Make sure there are extra batteries heavy duty wirings and the rest doesn't matter ....

And just to open up your eyes to another world in an Sq setup a decent pair of component set could cost you anywhere from 750 to 1500 easy. And that's just two 6.5 and two tweeters and possibly crossovers. So dream systems are based on what you are dreaming of - sound quality, pure bass or a good balance of both depending on how deep your pockets are :)

It's a 2001 Grand Am Se 4 Dr and no the seat does not fold down

have a look into building a box with the sub facing the back of the car and port it through the rear parcel shelf to get as much bass into the cabin as possible.

If being unic is important look at this guy

B&C 21SW152-4 21" Neodymium Subwoofer 4 Ohm | 294-689

This would also make you special but slightly less hehe

Dayton Audio UM18-22 18" Ultimax DVC Subwoofer 2 ohms Per Co | 295-518

Well for that you need other things then just subs and amps.

To many of us a "system" includes aftermarket everything and not just subs.... because then we say "subs" and not "systme" hehe. :p

I would recommend a ported 12incher with a 1000 watt and also upgrade front and rear speakers as well as put an amplifier to them with a bit of sound deadner on the doors and you would have quite a nice ugprade because then everything would be louder.