I'm currently running an Alpine X305 with the Imprint module. This is fed into an Audison SRx4 amp which is in turn driving Hertz HSK-165.4 comps up front and a JL 10W0 in a custom enclosure in the trunk (3ch mode 1 x 190W + 2 x 60W @ 4 Ohm).

I'm finding that the sub just isn't powerful enough so I'm thinking about doing the following:

Ditch the JL 10W0 and replace with a Hertz HX250D (dual voicecoil)
Bridge the Audison SRx4 to 2 channel mode (2 x 170W RMS @ 4 Ohm) to drive the comps (could maybe go full active but I'm not sure I want to at this stage)
Add a Hertz HE4 amp I have spare in 2 channel mode (2 x 200W RMS @ 4 Ohm) to drive each of the 2 voicecoils in the HX250D

What do you think? Good plan or should I do something else? Bare in mind that I already own the HE4 amp which is currently doing nothing.

 

will your new amp bridge? because if you dont get the gains exact you will bow that sub. but your plan is good, i find those mids/highs sound way better with more power. would not go active, use hertz cross over,

 

The other option is to buy another JL 10W0 and run the subs from each pair of bridged channels. Hmm, that might work better actually.

 

I think if you think your sub isnt powerful enough, may be look into a much more powerful amp for it!

I would get something like JL Audio HD900/5 and replace all the amps you have now. Save some space and less strain on your electrical system. Or just add a JL HD750/1.