dvc help

The amp you want to use is 2-ohm stable in stereo, and your sub has dual 4-ohm VCs.  Without adding a seperate sub amp, you should wire this system with amp channels 1 and 2 driving your 6X9's, and bridge channels 3 and 4 to ONE voice coil on your Audiobahn sub.  Do not connect the second voice coil at all.  This will give you 25 WPC into 4 ohms to the 6X9's and 50 watts into 4 ohms to the sub, which is pretty much the safe limit with the setup you have illustrated above.

Try using about a 0.9 cu ft sealed enclosure for the woofer.  I believe that is what Audiobahn recomends... but check the info that came with the driver or the Audiobahn web site first.

connecting only one voice coil will not damage the sub?  

Nope.

Powering only one coil of a DVC sub will not by itself damage a speaker.  It will change the output capability by about -3db and some of the T/S parameters so that enclosure calculations are not 100% accurate, but in the situation given for this question, that will not matter as the amplifier is far below the rated power capability of the sub.

The amp listed in the original question CANNOT be bridged into 2 ohms.

The only other option would be to wire both voice coils in series and present an 8 ohm load to the bridged amplifier.

(This is from the link bberman1 just posted, for those lazy ppl  ;)  )

With only one coil hooked up, a dual voice coil speaker will suffer a loss in reference efficiency of about 3dB (only half the coil windings are being energized) as well as a significant shift in its Thiele/Small parameters. This renders any enclosure calculations inaccurate unless you remeasure the speakers parameters with only one coil hooked up. Failure to account for the different parameters of a dual voice coil speaker with only one coil powered can result in very poor performance.

I guess its possible to hook one up, but you lose a lot of performance.