i have a VT Berlina, already have a system with Focal polyglass splits, 2 JL 12WO subs and Earthquake amps, PH 120.2 (running splits active) and PH 300.1 (for subs). Im not content and want more!!. I can spend $4000 so do i sell the lot and start again? I mostly listen to punk so i want it to be loud, clean and punchy.

I would sell everythign except the front amp

Drop the active, I would bridge the front amp too some high end splits. Heaps more power and heaps more volume.

Now depending on how good you are with fibreglass i would suggest going with only some realy high end 6.5inch two ways. Some Hertz Mille 6.5inch splits for $650 would be ideal.

If you can use fibreglass then u can fit some 3ways with 8inch Mids. In the doors, and the mid and tweeters in fibreglassed kick panels. To get this done by a pro would cost like $700 so its not worth it. SOmeone on the for sale forum is selling some kick panels from a New commodore ute. That fits both Tweeter and mid. I would get these.

Now I would run just one, very high end sub. This allows the box to be small-ish and be places in the best location possible.

I would be looking at a 12inch Brahma it has well over 2inchs of excursion so it will have much more output when compared to BOTH your current woofers.

Put the Brahma in a 4cubic feet ported box and tune it down to 25hz. This is what Mr Bob uses and has won many SQ comps and it will also go very very loud. The brahmas are so high quality even a 15inch Brahma would be as tight as your JL's even when its ported aswell The 15inch will be louder too.

Then you need an amp, As the Brahma is Dual 2ohm. U'd wire teh coils in parallel to get a 1ohm load. I would then Run a 1ohm monoblock such as a cadence. They cost about $1300 and put out over between 1000-1500wrms at 1ohm.

So far:

Splits: Hertz mille - $650
Sub: 12inch or 15inch Brahma - $1000 - $1100
Amp: Cadence monoblock - $1100 - $1500

Now i would spend ATLEAST $500 sound deadening the car. I would spend $100 on each door using high quality matting. I'd get two of the large packs available from teh CAA store. That would be enough.

The above setup would flog your current setup, and would sound so so sweet

I've just bought a VT Berlina so i'm going to start my install soon

I'm going for a single 12" Brahma this time, I had the 15" in my Pulsar and it went LOUD but it didn't suit my main type of music, punk. It was probably box design or something, not the sub, but I want a smaller sub anyway.

I'm just putting alot of deadener in the front doors, sealing them up, and putting a set of 7" splits in. Some 6.5" midbasses for the rear and suitable amps to run it all. Hopefully it'll sound nice.