12'' sub opinions?

You have a lot of SQ subs listed there.  I'd recommend looking at SPL specific drivers.  Check out Incriminator Audio linked below for some pretty killer SPL designed subs.  But also make sure you are setting your system up correctly.  That will make sure you don't blow your next sub.

http://www.incriminatoraudio.com/products.htm

The problem is that the W7 and 1000/1 wasn't a good choice for you.  The W7 is one of the best SQ subs on the market, and it can get really loud.  But if you want pure SPL, there are better choices.   The 12W7 blew because too much power was sent to it.  Whether this happened because the gains were set too high, or you turned the system up past clipping; it was still user error and not the fault of the equipment. If you push even the best stuff beyond their designed limits and they fail, it doesn't mean they are overpriced.  There is nothing piddly about the 1000/1.  It is an incredibly well built amplifier that can produce a lot of power even at higher impedances.  The problem is that you need a lot more power at lower impedances, and that's where other amplifiers will be a better choice for you. 

I'd suspect the IA subs set up correctly could get louder than the W7.  This will more than likely require a different enclosure and amplifier to get it there.  We have some SPL competitors here that could answer that question better than I can though.

Agreed - but we can certainly work with that beautiful (and NOT overpriced or overrated) amplifier -

Changing your diaphram in this situation will change absolutely NOTHING about the bass your system produces.  Nothing at all.  Okay.

You do NOT need another amp - that thing will make you deaf if you just hook it up to the RIGHT drivers -

I think your problem, wildkar, is that you are trying to get output from a single subwoofer - this doesn't really work - especially when you talking about a daily driver and all - jumping about brands isn't going to help do anything but get poorer - and I'm sure NONE of the subs you've listed are in any material way better than a freakin 12w7 -

For that thing to sound good at all you must have it a >2cft box?  JL gives specs for that woofer through a range so some precision would be helpful - but eitherway you need CONE AREA - not another hugely expensive woofer your going to blow.

To that end - why don't you try a PAIR of ported 12's?  At 500watts RMS you have a massive number of choices that would perform virtually identically to (at least as far as a car moving down the road at 60mph) a w7 in terms of SQ - and get ya another 6db ~ 8db  easy.  Or you could really get serious and parallel three 8-ohm 10's - that'd take care of your output problem real nice.

Reading over your posts, I can assure you that another 12 inch sub isn't going to do anything for you except lighten your wallet.

Remember - CONE AREA.

That all sounds very nice. If I had the luxury of going with more "cone area", rest assured I would definitely take that route if it was an option. Unfortunately I am dealing with a 2008 Mitsubishi Lancer in which the ported 1.75 cu ft enclosure takes up almost all of that trunk space quite nicely. That is why I am sticking with a single 12. I am not about to take the back seat out and build a wall. lol. I also find it very amusing that you talk about a 12W7 as if it were the god of all 12" drivers. It is an excellent driver don't get me wrong, but for strictly SPL purposes it can easily be beaten. I have been doing a lot of reading on that IA stuff! Thank you very much Steven for mentioning it. One death penalty series 12 should be more than sufficient for my needs. I guarantee I will not blow it on 1000watts, yet according to the test results from chad hicks, the output of that sub seeing that low power is quite impressive! (while 1000watts rms is not really low by any means, it is low compared to say 5000watts) I believe it is certainly possible for me to stick with the same enclosure and amplifier and only switch drivers and probably get more decibals than the godly 12w7.

Nothing at all??? I wouldn't go that far...

considering what u already have.... i think u should probably consider steppin up to a 13w7.... only thing u will need to change would be your box.....

the image dynamics is a great sub, but like the other guy said i think u might be barking up the wrong tree as far your choices in subs... if it's raw un-adulterated bass u seek... i should probably look at some ofthe more common stuff... not to mention... u can save a buck or two... and most times if u blow em up... u can do an over-the-counter swap with an authorized dealer... no sending the sub out and waiting for it to come back......

NEVER FORGET..... JL AUDIO IS A 'SOUND QUALITY COMPANY'... they don't own a single spl or db related record.. and u know what.. they have to aspirations to do so...