Running that amp at 1 ohms is like putting it into overdrive, while it will put out more power, it is also going to produce a tremendous amount of heat and will produce clipping. Any amp can run below it's rated impedance, it's just not good for the amp or driver.

The box is equally important as the driver, with the same amount of power in a proper box it will get louder and cleaner. I would definitely look into upgrading your amp, but the box should be your first priority for now. I know too big of a box and you run the risk of bottoming out the suspension, not sure if the same is true for too small. But don't expect the 15" to get as loud as your 12" running at 1 ohm, just won't happen. Even at the same impedance, the 12" will be marginally louder while the 15" might pull a head in the real low notes, but not in that box. ( on the same 500w).

I must have worded something wrong, your not going to damage or break the cone. A weaker cone will start to distort with too much power. Although what is really limiting your sub from seeing the same power as modern L7s is the voice coil and suspension. Not so much the cone.

 

ohhhhhh now we gettin somewhere....ok then..im learnin im learnin.... that cud be why my amp gets soo hot but then again when i had the L5 it never clipped or then again i may not have been able to tell...

yes i figured the box is pretty important...lol..jk...but yes the amp will definitely be upgraded...i thought about a 750.1 since u said thats around my range...and i understand the power to ohm to size ratio...

and with modern subs and the one i have....if i change the box to a proper ported one and proper amp rating...say i gave it...800...and i had an 07 or maybe even the new 09 L7 in the same box and same amp with same rating...would they sound completely different??..marginally different?? or more like ive completely upgraded in every aspect different?...

thx for bein patient...i like asking questions that way i really wont have to ask em again...plus im thinkin about trading this sub i have for a 15 L7 09 or 08 version or maybe even a 12

 

Clipping does not make a clip or clicking sound, it sounds like very distorted bass. In speakers it has an almost fuzzy sound to it. A new L7 sound be significanlty louder, have more punch, and be much cleaner in a sealed box.