The specs i found indicate that it only has 250 RMS. Maybe a typo? As well it says the Sub has a low pass filter? WTF??? im totally lost on this part.
http://www.commsandsound.com/qtx-sound-qt18sa-smwa18-active-sub-18inch-1000w.html
A couple of things u should look for in an Active Subwoofer, does it have a limiter, (you should get a sub that has one in case u make any mistakes, and it wont blow the sub), and lastly Durability.
I really really really must stress the importance of buying quality over quantity. The money you spend on a system is pretty much directly related to the quality of the item. Dont cheap out on something that you will have to get fixed or doesnt work perfectly 100% of the time. Having to spend money on repairs not only costs you money…but could end up costing you gigs.
We learned this the hard way…we decided to pick up 2 mackie subs instead of the yamahas cuz they were 150 less per sub…and we ended up having to get them repaired like 3 times…thank god we had the extended warrenty and were able to trade them in and spend the extra cash on the yamahas.
Oh and when possible, buy from an actual store…it is a lot easier to get things RMA’ed and fixed if u know the people u are buying from instead of joe blow that is online and only wants to make the sale.