Not Enough output

I have 1 Kicker L5 12" sub in a vented enclosure. When I first got the sub I was pretty impressed with the output, but now I want more. I have a Phoenix Gold 500.1D amp running the sub and it is way too much power for this particular sub. So I am looking at going with 1 Memphis M3154D 15" dual 4ohm sub in a vented enclosure running off this same amp. just wondered if anyone has any opinions on this sub?

My future adds will be Memphis 8" mids in the front doors, Memphis 5 1/4 mids in the kick panels, and Memphis 5x7 in the rear for rear fill. Right now all I have is 5x7 in front and rear doors. They are clean but not enough midbass for my taste. 

you could go with the kicker solo X line.

I'll never buy another Kicker product. Sorry, just my personal opinion.

"...but now I want more."

Ah, doesn't that sound familiar?!!

Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

May I ask why. I know some woffers my not be what your looking for but too swear off an entire line is kinda brash

i said he could go with the solo x i didn't swear off the brand.

Hes talking about me.

Lets see, I've had two 12" comp vr subs take a s**t. I don't like their mids and highs. Don't like their amps. And the L5 that I've had for a little over a month is getting ready to take a crap. I can play it for 2 minutes and my car smells like an electrical fire. I love the smell of burning voice coils.