sound setup , fine tuning

2009 Pontiac Vibe 1.8L,Kenwood KDC-x693 HU, Apline PDX1.600W, Alpine PDX4.100W, Stinger 1 Farad Cap, JL Audio 12" W6v2 in Pro Wedge, Alpine SPX-13Pro 5 1/4" Comp (Front), Alpine SPR-13C Coax (Rear), Dynamat Extreme Front & Rear Doors...

I am running  the stock passive crossovers with my Alpine Components, I have the Xover settings on my Kenwood HU for the fronts and rears set to 'through', my first question is what setup should i have for the subwoofer slope (-6,-12,-18,-24dB/Oct), second question is where should i set the HU subwoofer low pass filter (30,40,50,60,70,80,90,100,120,150,180,220,250,Through (HZ)), third question is what is the correct level for the subwoofer  or is this a personal preference (-15 to +15).

Highs and mids sound great, but just not getting the lower end punch I was expecting...I had the gains set by my installer, but they might need to be increased.

Also, this HU offes a bass boost feature...again is this a personal preference things or should I turn it off??

And last but not least, I set the EQ to just one of the presets, do you recommend I set this up manually, I will need help, or just let it stay where it is, sorry that i a really vague question, but I just do not know where to start on how to setup an EQ.

I want to address these fine tuning issues, before I address what maybe the cause (need to do the big 3 and change my alternator)...hopefully i will not have to change my alternator...

Thank you for such a quick response.

I will adjust the amps and HU accordingly. 

Regarding the Sub Level, it was set to zero when I picked up the car yesterday evening...Only when I increased the sub level from 0 to 13 did I start to get any real bass or punch...I will give him a call to confirm.  At first I didn't have any low end, then I checked the connections and one of the RCA cables had come loose or was not pressed secure, once I fixed this, I started to hear the sub, then I started to check the HU settings and found the Sub Level etc...

Should I reset it back to 0 or will I need to reset the gains on the sub amp??

Regarding the bass boost, i currently have it set to 'off', i really didn't notice a difference when it was engaged, of course that could simply be a case of my ears.

10/4, I will check with him just to be sure.

When i set the filters to "off" on my amps, will i need to adjust the crossover dial up or down or is it disabled once the filter is turned off?

Just for my own education, would you mind explaining the why the HU should control the Xover/filter instead of the Amps?

Thank you sooo much for your help!!