Sub/Amp wiring question
#2
Assuming the DVC is a "4+4", you can run it as an 8 or a 2 ohm load. If you run it at 8 ohms, it would probably be stable but you won't get much current though it. If your amp is 2 ohm stable, that would be your best option. Otherwise, you could buy another identical DVC cone and run them as series/parallel and the amp would see both of them together as a 4 ohm load.
#3
Assuming the DVC is a "4+4", you can run it as an 8 or a 2 ohm load. If you run it at 8 ohms, it would probably be stable but you won't get much current though it. If your amp is 2 ohm stable, that would be your best option. Otherwise, you could buy another identical DVC cone and run them as series/parallel and the amp would see both of them together as a 4 ohm load.