Questions on a build........

[Thane Ector]

I am currently running (2) Skar DDX 10s on (1) Audiopipe apcle-18001d at 1ohm. I am undecided as to run (1) 1800.1D to each sub. Or run an apcle 30001d to both. Or run (4) DDX 10s on (2) 1800.1D. Or just get (2) 2ohm DDX 15s and run an 1800.1D to each sub.
Plus which is better sub & port front (currently running it this way), sub back or subs up (against the hatch)? The vehicle is a C4 vette.

[Grinder]

Welcome.

Not a lot to go on here. You might help others to help you by describing what you like and/or don't like about the current setup, and what sort of performance improvement(s) you're hoping to achieve; and your preferences and goals for the system (SQ/SPL, music tastes, budget, etc.).

Also, what sort of cabinet(s) are those subs currently in (sealed/vented, prefab/DIY, net volume, tuning frequency, etc.). Are those subs D4 or D2?

<edit> I'd suggest starting a new thread in General Car Audio, as any responses to this thread (in Introductions) don't appear to show up in the Live Feed.