Okay so impendenece is the volts from the battery divided by the resistance? Which is ohms or omega? How do you know what the impendence is suppose to be for the system? Does it change for every sub? And where do you measure omega from?
your getting pretty d@mn lost and confused LOL!!! So let me make this simple. subwoofers can come in single voice coil or dual voice coil. If its a single voice coil that says its either 2 ohm or 4 ohm, you can wire it straight to the amp at those impedances.
However, most subs come with dual voice coil configuration so you can choose the type of wiring you want to get a certain impedance to work with your amps.
If both your subs are 4 ohms DVC(dual voice coil)
Subwoofer Wiring Diagrams, Two 4 ohm Dual Voice Coil (DVC) Speakers
those are the impedances you can get.
If they are 2 ohm DVC subs then
Subwoofer Wiring Diagrams, Two 2 ohm Dual Voice Coil (DVC) Speakers
hint* ^ the site is pretty useful.
Why does impedance matter? because if you look up any amplifier's specifications, it will say how low of an impedance the amplifier can handle. The lower the impedance the more power you get, along with more power draw to your electrical system but your running pretty low power it shouldnt be a problem.
If you wire the subs to an impedance lower than the amp can handle, then its Bye bye amp and woofers.
http://www.mydepots.com/ebay_images/car-audio/QA-D-Series-User%27s-Guide.pdf
this is an owner's manual for your vvme amp(its actually a rebadged innotech amp) it says its capable of 1 ohm. So make sure to find out what impedance your sundown is so you can get matching impedance. If its a D2, your going to need another D2 sundown SA12 and then you would need an amp that does 1.2k rms at 2 ohms wired in series OR two 1 ohm stable amps for each sub with each wired in parallel. If its a D4 then just grab another D4 SA12 and wire them parallel to your vvme inno amp
D2 = 2 ohm dual voice coil
D4 = 4 ohm dual voice coil just in case.
