went out and bought me a cheap advace auto cone filter yesterday and put it on. it feels like i did loose some low end but when compared to the gain in upper end and the sound id say that the 20 dollars spent on the filter and the short amount of time spent installing was more than worth it. does anyone have any # confirming that you do lose in the lower end or is it all just speculation. from what i can tell its almost like the bottom end just stayed the same but the fact that there was such a big gain in the upper it just feels like you lost. again thanks for all the info.