I've always run Alpine. Beat the snot out of a 12" type-R and the thing is still solid as it was when I bought it. It isn't in my truck anymore but my brother who is a lot meaner to it than I was is still using it and it sounds solid... In comparison my buddies Sony subs have blown twice.

 

check your wiring on the sub. make sure (+) goes to (+) and (-) to (-). thats the problem i first had. also, do your subs have an ohm switch on them? from, lets say, 4ohms you can switch to 8ohms? check that too. other than that, theres nothing else that could be wrong unless the amp is pushing like 25786892734689756 watts to a 500w sub...

 

Though I agree with most of the above replies about better subs. I will add if they worked before and the issues were only after the installing in the Ram then what changed??? IS it a mono amp or 2 channel one per sub or 2 channel set up for mono? Did you go from a series to Parallel wiring?

 

double check to see if your subs are hitting the back seat when they pound? you might need a spacer in there. my truck has like an inch spacer on the back. i have two cvx 12s and a 1200 watt kicker amp and ive had no problemns. its been in there for about a month now

 

sorry to say just as well as others but sony sucks when it comes to in-car stuff. if i were you i would keep your mtx amp and getsome mtx thunders. those are pretty sweet. to save some money i always buy my car audio on ebay...it ALOT cheaper than in the stores. MTX is sweet. I have owned nice pioneer 12"s which pioneer sucks now and i just recently got rid of my infinity kappas whichwere ok but not that hard hitting. SONY SUCKS, but keep your mtx amp...sounds like a nice amp. someone else also mentioned alpine type-r's. those are pretty sweet too. most of the time from what i have seen at big electronic stores like circuit city, best buy, stuff like that is they carry the low end of each brand. so check on ebay at some alpine or mtx or if you have money JL is always been great but expensive.

 

i would check see what the amout of air your subs need also, there may not be enough airspace in the box you have under your seat, a sub that worked in a box in the truck of a car vs under the back seat has much different airspace and under the back seat you won't hear them as much so you tend to want to turn them up louder maybe distorting them, i've never has sony subs but have heard that the subs weren't very durable. Hope you can fix your problem really suck that you have went through 2 sets of subs. I personally have 2 12" jbls in a fox acoustics box under my seat and have had no problems

 

its not necessarily the subs guys. i know, its sony. but its not as bad as you all think. dont mind that. either the subs are wired (+) to (-), youre getting 76548632786537896 watts RMS to the subs with 250 RMS, or you have no airspace for your subs. what kind of box do you have? wooden or fiberglass? if its wooden, theres your problem! fiberglass is the only way to go in a truck for under the seats.

 

wood wont make a difference. it the airspace, power, install issue.

 

wood doesnt capture all the airspace you need under the back seats. fiberglass is thin and gets all the available airspace. it does make a huge difference. also, you have 12's... 10's should be the biggest you fit in a ram under the back seats. airspace...

 

i have 12" under my back seat and have plenty of airspace it just depends on your box as to the airspace that you have