two 10’s or one 12?

After reading all that talk about whether or not 2 subs is better than 1.  I have to say I have been satisfied with my one 12" sub.  I feel it gives enough bass, but I still want more.  Is there any possbility it's my box specs?

Another thing is I have been thinking about upgrading.  And have been wondering if one 10" is good with a well made box or is it worth spending the money for two "10's or is it better to go with one new 12" sub?  I'm not sure which of these would sound the best.  I just want enough bass to fill in my tunes...nothing extreme.  I'm currently running the old RF 12" punch Z series.  It's okay for the amount I paid.  Just looking for a bit more.  thanks

Yes, there is a possibility it is your box specs.  An incorrectly designed box can suck the life out of an otherwise decent subwoofer.

2 of the SAME subs, correctly installed, will be louder than one.  However, put a single sub, even a smaller one, of excellent quality against 2 "normal" lower cost subs and the single sub can certainly win.  

For example, put a single adire brahma 10", or some of the higher end offerings from Eclipse, JL, Infinity, Image Dynamics, RE, MTX, etc. against 2 12" 150w rms punch subs and the single sub probably will win in terms of SQ and SPL every time.

i made two 8's sound louder and better than two 12's powered by the same amp.

ITS ALL IN THE ENCLOSURE!!!!!!!!!!!!!!!

Read my other post about my fosgate RFR3110's. I just changed from 3 MTX 8000 10's to the 2 RF's and am VERY PLEASED!

BTW, many people have 1 high end sub in there rides. You can go all out and get the best since you only have to buy one and as stated above, it's mostly in the enclosure. Can you imagine 2 18" RF punch pros sounding terribly with plenty of power? I can and have seen/heard firsthand, and all because of a crappy box.  The guy spent all his $$ on the subs and amps then tried to build his first enclosure. Ported too. When he finally had the proper size and quality sub enclosure built, nothing and no-one around could touch him.

If I remember correctly, the old Rockford Z series were crap.  Still, it may not be performing to its potential if it is in the wrong box.  Check the specs for the recommended sub enclosures. Ported yields more output at the cost of SQ.  Move the enclosure around, face it up/down, left/right, move it forward in the truck/hatch, move it back, it can and will sound different depending on where you put it...  .. I just said what /r7 said, we are both right.

"I feel it gives enough bass, but I still want more. "  If you upgrade that RF to a higher quality sub you will hear and FEEL the difference.  If you have been getting by with this and just want a little more then a sub upgrade could be what you are looking for.  Try JL Audio w3 series, Alpine Type S, and Infinity's Kappa Perfect.  Many other good mid-high end subs out there that will work, just be ready to feed them the watts they need to perform and enjoy.