Mr Slabi

I see a few posts about the SW10 series powered sub. I have an SW10C and was wondering how this sub ranks with you pro's in this forum. I have been pretty happy with this sub for the most part...But as of late It seems to bottom out more (very loud pop on heavy bass effects). I have a Yammy RX V1070 reciever for power. Is this one of the better powered subs out there? Could I be overpowering the sub with the (low level output) setting? If I remember correctly the problem may have started with the purchase of a dvd player and movies such as (Matrix,T2 and eagles(hell freezes over)) Could it just be that with the addition of the dvd I need to lower the settings a bit? I am a newb compared to you guys, but have had this sub for about 10 years and this is my first complaint. Thanks in advance.... PS. What might this sub be worth in excellent condition (which mine is other than the occational pop).