Why buy lots of watts?

Here's my question back at ya...Why drive around with the added weight of the additional enclosure and the inconvenience of the space it takes up in your car if all you want to do is power half of each sub?  My advice is this:  decide on the reasonable limit of SPL you want in your daily driver, then find the sub/amplifier/box matchup that will give you this.  Around here gasoline is $3.12 a gallon today, and excess weight uses it up faster.

BTW, the parametric EQ just rearranges the preamp signal.  Low sub bass signals still require much more power from the amp than higher tones.

First, amplifier power really has not much to do with a decision to power one or both voice coils.  I disagree with those who wire only one VC trying to maximize amplifier power output and think it is a cop-out approach.  Sure, if you are careful nothing will be damaged, but why only utilize 60% of a systems capability?  The power rating using one VC is about 60% or so of using both.  The reason you need more amplifier power is not to get louder but to handle the dynamic peaks of your music without clipping the amp.  If you are boosting your system using an EQ beware, as this is a very easy way to drive an amplifier into clipping and destroy your speakers.  Realize that a +3db boost from your EQ will demand twice the amplifier power at that frequency.  So if you are using, say, 100 watts nominal and then you boost 63Hz by +3db, any program material around 63Hz will suddenly demand 200 watts from your amp.  +6db will demand 4X the amplifier power.  If the amp is too small, you can clip it very easily by boosting with an EQ.  And lastly, I never recommend using only one VC of a DVC woofer unless you do so for a very specific reason (like trying to target a specific Q for the system.)  Wire all voice coils and simply setup your amplifier properly.  If you are using an EQ to "fix" a problem in output levels, you need a better probably larger amplifier and maybe different speakers too.  Sorry.