i just spent all day trying to fix my broken ml sub. i purchased 2 10ib4 jl subs from a guy on craigslist. i read somwere on the stickes that this type of sub was a direct mount. i had to make an MDF board and i plugged installed everything and it sounds weak. i think the ml had better output? did i do something rong? black to negative yelloww positive. idk how good i connected them or if that would make a huge difference? what to do what to do

 

The JL probably isn't as efficient as the stock sub, you're best bet may be to get an aftermarket amp that will give it a little more power.

 

If the sub isn't powered, then there is your problem.

But even if it is powered, most IB setups don't go nearly as loud either unless you get a nice big sub with lots of air displacement. At that point, it's kind of heavy so your rear deck may not handle the weight.