Exactly (not a good idea). If you wire up only one coil, the powerhandling gets cut in half.Some people say that you can wire only one coil, but I just had a thread on it, and it didn't sound like a good idea.
for abou 25 a driver you can get dual 4 ohm coils...final load of 1 ohmI'd go with 1 magnum or 1 RE HC becaues both of the subs are dual 2 ohm, so you can get a final 1 ohm load. Some people say that you can wire only one coil, but I just had a thread on it, and it didn't sound like a good idea.
That BX1500D is 1 ohm stable, so you would be able to wire only one of those subs (either the D2 or the HC) and achieve a 1 ohm load.
for abou 25 a driver you can get dual 4 ohm coils...final load of 1 ohm