I've been thinking of doing 4 DCON 15"s. I need help deciding if I should do s4 or d4 voice coils. I haven't chose an amp yet because I wanted to make sure I was getting the right equipment.

once you have an amp selected then order subs... how else would you make the decision?

Plug those speakers into this.

 

http://www.the12volt.com/caraudio/woofer_configurations.asp

 

This will give you you final ohm loads.

I ran the subs into that program and I decided on four D4s for a final 2 ohm load. The amp will be a Crescendo 3500d for a little extra headroom. Thanks