ok im new to talkbass so i hope noone has dealt with this yet. i did a search and nothing came up. I bought a Hartke kickback 15 its a 120 watt combo amp. At low to mid volume it sounds great. but when i got to crank it up past halfway on the volume it loses it tone and just farts at you so bad it unreal. I have the eq set as follows shape 75% bass 65% mid 57% and high 45% i gave these figures based on the knob all the way off is 0% 12noon is 50% and cranked is 100% just so there is no confusion. I thought the speaker might be in the process of blowing out but when i pulled it out and checked it it was fine. THe amp does not have and ext. speaker jack so i could not see if it was the head. but it runs just fine so i dont think its that. I have never used a aluminum cone driver so i though that was a possiblity. what do you guys think?