Summary: This thing is awesome!! I have it hooked up to a hifonics brx2000.1d amp and I have a 2.25 cubic ft enclosure (needs a 2.75) but dang!! This sub is wired to 3 ohms and is pushing about 1000watts rms. this thing is definitely underrated! This thing also ways a ton and is quality built with gold plated terminals and every thing. It's good for SPL and SQL. It's worth every penny!
Summary: By far the best car subwoofer I have ever heard. This thing produces clean and deep bass that hits you without no annoying distortion. I will own this babe for a nice 10+ years. When your looking to buy a subwoofer, you have to ask yourself how good is the bass. When you look at other lowered price woofers they all have 5 star reviews, so whats the difference between the $100 ones and these ones? If the bass is truly the same then you would buy the lower one.
Summary: This sub lives up to every 5 star review. It is a total beast and produces some incredibly detailed bass. I have 2 now - one in a sealed 1 cubic foot box as suggested by JBL for optimal sound accuracy and another in a tank of a ported bassworx box. Both are made of 1" mdf. Thick heavy beastly bass boxes. I have a 2000 watt mb quart amp feeding them and it seems adequate but they could handle more.
Conclusion: wow, what can you say. for starters this sub is rated at 700Watts RMS, but it is quite capable of handling much more! i did contact jbl's tech support and engineering department when i hooked this sub up to my planet audio BB2400.1, i told them that i was sending ~1200 watts to this sub. there response was something along the lines of "oh yeah i know it can handle power." it does get hot but then again this was a subwoofer engineered to take heat.
Summary: I bought 2 JBL W12GTi MkII, 4 years ago, and still bring a powerfull and deep bass, like never before i heard. this subs, need a big responsable amplifier, i had a Power Acoustik 5500 (peak) 1700 rms 4 ohm. but remember this subs had 6 ohm, so for avoid damage it amplifier have 755% gain level. so no extreme for amplifier and no extreme for subs.
Conclusion: I got two gti's when they first came out and got sick of them blowing out. Then i got 2 L7 12" kickers. Not only have they out lived the gti with same power output but they bank way harder way longer, sound better, etc. Buy this speaker at your own risk and if you do purchase a jbl amp. They last longer and are under rated. I did have those for a while and were cheaper and put out for a long time before they gave up on me.
Conclusion: I have two of these breathtaking beasts and they are simply flawless JBL doesn't lie when they say the ultimate woofer, sure there are subs out there that can take 3500 rms but this gti doesn't slack when I first got this I didn't have the 2nd one so I hooked it up to my bpx 2200.1 all by it's self and gave it 2200 rms in this small little sealed box I had laying around and it took it for a good half hour, I wouldn't do it often but it will take a lot more than 700 if...
Conclusion: I owned a single JBL GTi for little over a year when i was first starting out. I had it hooked up to a rockford fosgate 800.1 amp, little did i know this subwoofer could handle so much more power. I finally upgraded to a audiopipe ap3000.1 class d amplifier and wow can this subwoofer handle power!! I've been running about 1200 rms though it for a few months, never any burning of the voicecoils or anything, always a very clean sounding sub.
Conclusion: I upgraded from a 10" Alpine Type X in a ported enclosure to this MkII in a ported, spec'd enclosure powered by an MRP-M1000. I have the gain set about 60% and the low pass filter set at 80Hz. I usually listen to country, rock, and rap at moderate levels, but this sub sounds great even when I want to rage. Blends beautifully with the front stage, and the response in the ported enclosure seems fairly flat (good thing) and surprisingly quick.
Conclusion: This SUB is by far the best sub i have worked/heard. i have been an installer for 8+ years now and this sub blows away anything i have worked with JL W7 had 2 of them this one is way better in SQL and SPL have it in a ported enclosure port tuned to 36.5 hz internally braced box with 10+ braces just listen to it or check the reviews