I've got a Polk C500.1 monoblock class d amp, rated 350w@4ohm, and 500w@2ohms. 2ohm stable amp. I have an Infinity 10.1d DVC subwoofer (just 1) rated 350w RMS, (or 175w per coil). each coil is 4ohms. 1400w peak (or 700 peak per coil) Now, this sub is also rated acceptable for "free air" use. My K5 is all fiberglass body tub (US Body), and where the OEM K5 sidepanels (the cardboard ones) would normally go in a steel body , I have a fiberglass panel, that is part of the body, effectivly creating a quarter panel cavity. 4" thick at top, 7" at bottom (where body side swoops out). Same cavity where taillights mount in the rear, and I will have the rear speakers (6") mounted in a more forward position on this panel as well. I will be mounting the sub to this panel (and in the cavity) (why, because I value my space, and I really don't like sub boxes) This cavity, I esitimate to be about 3-4 times the recommended ported enclosure volume,so it will effectivly run as "free air",which according to the manufacturer, will cut it's rated power in half. (which is part of the question, I don't really get that statment, will it be cut in half, or are they saying, don't put more than half of 350 into it?) So, with that said, how should I wire this sub to the polk amp? Present the 8ohm load(wire the coils in series), or the 2ohm load (parallel wired coils)? My concern is if I go the 2 ohm route, I will me massively overpowered (or will i?)and blow the sub. But I don't have a good enough understanding how speakers and amps work together. The amp has 2 sets of speaker outputs (only 1 channel though),they are just parallel wired if you hook a sub (or a coil) to each set. Here's the amp wireing chart: Any insight, is, as always, greatly appreciated.