Well based on JL's ( http://mobile.jlaudio.com/pdfs/11415.pdf ) recommendations of 1.75 Per sub = 7 total and I give 2.0 for port and sub displacement were at 9 cubic ft total. This is tuning of 30 hz and an F3 of 35hz repsectively.
This will give you some idea's on how you can go about building it. Just put bracing inbetween the subs and you should be good to go. The measurements are 14" width - 22" height - 57.5" length and Port is 5.5" width - 12.5" height - 26.125" length!
Edit: This keeping in mind that you'll be using .75" thick MDF or equivalent!
I would go with the one you can get a warranty on, I would imagine that both are made in korea or china both make great power per dollar so If you can get a warranty with one and not the other then I'd go with it. If neither then I have no guess for ya becuase I think there both great for the money.
Most not all vehicles will see a lower score at the dash verses the kick, I think why you'll see so many people ask here is most of us came from termlab which is a DB Drag competitor site, at least I know I did.
I wonder how well control is at that high of excursion especially with a ton of power to it. It'll be interesting to see the spec's of this if and when it hits the shelves.
have you read everything at www.the12volt.com ?? there's enough there to pass the basic and possibly the installer first class cert's, in my honest opinion!
In direct current yes, but what comes out of the amp is alternating current so 10 ft or 100 ft wouldnt make a difference. I think its the size of the box or bad coil. I have seen this similar issue with to large of a box hence the "No cone control" or a bad coil all ready.
Also in series parralel's that I have done in the past the woofers closest to the amp would see to move out of phase with the others and it may be that they get a little more, also is it a single chamber or all chambered off?
Is this visually, or on video? becuase on video alot of cameras cant pick up the subs moving properly, howver if it's visually I would check to make sure there wired in proper phase.