i got a 15watt fender rumble series practice amp last year, somehow, at school, i blew it up. I sent it to fender, they sent me a new one and i guess the last one was a lemon cause i like this one; except that the cone sucks. it's a paper piece of crap that "farts" as soon as i put the volume past 9 oclock. Would it be worth it to change out the speaker cone for an aluminum one like in my hartke? or should i just keep it at a low volume?