I have 4 12 slightly used pg octane zr subs. They are in great condition, and sound incredible. They are hard to beat for the price, and are some low end mosters as well, and they get very loud. Ive had them for 2 month, and Im getting rid of them because I change out my setups every couple of months, so I have no need for them anymore. I think 50 plus shipping for each sub is very reasonable.
