Sub Enclosures????

I say you try a sealed enclosure seems to be best for what you want to achieve!

A sealed box requires more power, so stick with a ported box if you're going to keep that as your sub amp. Those JLs might not want to be in a ported box either, so find out their specs. Usually bandpass subs are for a bandpass box only. Really though, a bandpass box is the most efficient use of your low watts.

A sealed box gives the most accurate sound, and is what I prefer. Quality, not quantity.

Typically, if you don't give a woofer sufficient power while in a ported enclosure, it doesn't perform very well. But you could still try it, I have no doubt that it will still play decently well. I would probably recommend that you use your 4channel amp for your component speakers and get a single channel class D amplifier for your subs. Most multi channel amplifiers are not class D, and thus tend to overheat quite easily.

From my experience, most of JL's subwoofers are not designed to play loud as much as they are designed for sound quality. With this in mind, you may opt for a sealed enclosure instead, simply because of the sound quality advantages.

The manufacturer should have recommendations as to what type/size of enclosure to use.

This information should help you make a final decision.

Here is some info on enclosures, some stuff you may already know, but...

http://spkrbox1.spaces.live.com/

I say go with sealed and fill it with poly-fil b/c with the lack of power the poly-fil will give it more power.

sealed