ok so in my truck a friend put in his old JL audio 12 inch, i never checked what it was just let it be and had my 776w pioneer amp going to it... well i ran it like this for months and it was great, but i checked what it was today and its a 12W0, so its a low end sub so i grabbed another sub to try it out a TS-SW124d... it sounds the exact same and the RMS wattage on the TS is nearly 3 times of what the JL was, i dont know a lot about subs but how is it that they seem to have the same ammount of power?
It could have to do with the box that you are using, or maybe the way the jl sub was built. there are a lot of things it could be. That sub is still an okay sub even though it's their bottom line. You also could have messed up wiring on the 2nd sub, like i said, there are a lot of things it could be.
A sub's power handling has nothign to do with output. A sub rated for 350w RMS could be louder than a sub rated for 1000w RMS. The WO line from JL are very efficient subs. They perform at their best with very little power. The other sub could be much less efficient and not reach its full output with the amount of power given. Either that or both subs are similar in output.