A mate sent me this a while ago and I have just found it again and thought I would post it up for all to see......
"Many thousands of hours have gone into the conception of the Quadrasub woofer. Will the cone hold up? Will the basket hold up? Can we effectively align all four coils exactly in tune with each other? And what will happen when we put the kind of CONTINUOUS power into these speakers that has never been accomplished before by any company. We, after all the work, have accomplished all goals and the "Quadrasub" woofer is ready for the world to hear. Our patent pending Quadrasub woofers can not be out performed. As we hold the rights to multi coil, multi magnet designs of various configurations. We build them so that even one coil can handle more power than any other on the market can, then we solidify it by adding 3 more.
The QS21 has been tested with 8 Hi-Fi car audio class D amplifiers rated at 1200 watts each. It has been tested with 4 Professional Crown K1 amplifiers. In both cases the woofer didn't even come close to voice coil over heating or epoxy melt down. What will this woofer REALLY handle? We don't even know yet. We can't seem to blow one up! We have also developed a quad coil for the quad woofer. Giving the woofer 16 coils to connect amplifiers too. We have tested this woofer with 16 1200 watt class D amplifiers and it did handle the power for the 2 hours it was tested. That is over 19,000 watts RMS continuous.
4 massive 4" black anodised aluminium voice coils (16" collectively). Coils using 20 gauge American copper, with 4 layers of wrap at 1.875" tall. 4 massive 200 oz. bumped magnets for a total of 130 LBS packed into 21 inches of shear power and brute force. Using our rigid, unique Poly Resin Basket.1.5" fat rubber surround, flat piston, carbon fibber cone and 4 long throw 7.5" spiders
This woofer is built using techniques to cool the voice coil which is one of the most important factors in power handling and long term life span of the woofer. Cooling vents in the basket and vented pole pieces. The coils used in the 21 are absolute monsters! 4 layers of the heaviest gauge wire possible is used for a total wind of 1.875" tall so you are sure the coil won't jump the gap.
A rubber surround is used on all of our woofers to insure a long life span and resistance to sun, heat and water. Reinforced carbon fibre cones keep the integrity and strength of the cone in place during operation and also guarantee it's life span. We use 1.25" braces across the bottom of the cone and attach them from coil to coil. This insures that the cone will not warp under intense pressure and also guarantees the alignment of the coils.
RMS power: 10,000
Peak power: 20,000 watts
Frequency Response: 22-700hz
OHM Configurations: Available in many configurations below:
Dual 2ohm coils---8 x 2ohms or 4 x 4ohms or 4 x 1ohm or 2 x 4ohm or 2 x .5ohm or 2 x 2ohm or 1 x any ohm load in between.
X Max: 1" from rest position to peak excursion.
X Mech: 2" (linear travel in the gap)
Weight: 130 LBS (Don't pick this up by yourself folks!!!!!)
* Free Shirt
* Lifetime warranty against any defect
* User manual
* Hole cut-out template
* Black Basket and 1 beauty ring in Black
* Jump cabling for voice coil configuration of your choice.
* Each woofer comes with a birth certificate and test reports.
* Shipped in a custom wood crate
* Red, Yellow, Green, Blue, White or Black beauty ring.
* Dual 2ohm voice coils"