Should i changes my sub to Fathom f112 or f113

For the record, I've some experience with the Supernova MKIV 15" sub. They are indeed excellent all around sub's, with plenty of output! I haven't run into a situation where I could bottom one out on their own, personally. As for music, not bad either!- and they blend very well.
All of this considering proper setup and tweaking, as usual.
Basically, I've gotten plenty good results with it.
Now, I would give the nod to something like the Paradigm Servo 15 for musical accuracy and speed. Infact, for $1500, I never have heard any sub that out-matches the Servo 15 for HT/music dubties for the money. Simply superb subwoofer, and a killer bargain!
However I've never heard a single subwoofer that I thought, on it's own, was the end-all-be-all of subs though. So, for the record, for the price of a single JL Fathom F113, you could buy TWO PARADIGM SERVO 15'S and have more dynamic headroom (two 15" subs of this caliber would allow you to run each sub with more efficiency, and less taxing on each), less distortion possible (properly placed, dual subs will cancel out any distortion differences between them, so you only hear their similarities), and simply more brute output than one single JL Sub! Of That, I garantee!!!
Plus you can run "stereo sub woofers" with two Servo's.
Of course, you wont' have that shiny black lacquer finish, then - lol
Just some thoughts. But, you can always pick up a JL and compare, and then you'll know

Depending on your goal there are a few factors to consider. Powered subwoofers have become much more sophisticated with the inclusion of EQ and or room correction.

My Supernova benefitted from the Velodyne setup program. Still the Supernova is limited to crossover, and volume. IMO having multiple EQ presets with my Velodyne DD makes adjustments to film and music audio a snap. With the Supernova I have to adjust a very sensitive volume attenuator.

My experience with the fathom is simply showroom. In that context they seemed to be a fine sub sonically. You'll notice some of the review testing was done using the Velodyne program. I'm not trying to make a point for Velodyne but their day to day usability suits my requirements for adjusting the sub to fit the material I'm listening to.

Two subs can load a room better than one but it's not necessarily a requirement.

Thanks for all your feedback,so far didnt decide yet which sub should i get.

Gigolo, keep the Earthquake and get an SMS-1

http://velodyne.com/product-accessories/management-systems.html

They're selling them new for the used price. The 15 is really a hairy sub. EQ it with the SMS then run the room correction on your new 7.1.

Iplaynaked's advise is still pertinent. Spend the savings on a better pre/pro.

I'd also suggest replacing the AVR before addressing the subs. You'll almost certainly end up with some sort of digital bass management (Audyssey or similar) that will DRAMATICALLY impact the performance of the subwoofers. This may also make the Velo SMS-1 (a solid product and a very good deal, I used one for years) recommended by Vicdamone duplicative.

HT is the only area where I'd say choose the electronics first.

Marty

PS If you do replace the subs and have the space for it, a pair of 12" Rythmiks (at +/- $1600) is worth thinking about - rather than a single f113. I love the JLs, but ultimately felt that a pair of Rythmiks was probably the better deal. YMMV.