A:AnswerI'm almost sure that this speaker will accept both types of connections I own one for use with a Yamaha sound bar and it has two cable connecting ports in its rear one left and the other right it also comes with multiple wire entry ports. If your not sure call or visit your local store to confirm. Hope I was of some help.
A:AnswerIt is a powered sub woofer so it is not 8 ohms, it is high impedance with virtually no load. It can use a speaker level feed or a line level feed. It should integrate with your 2.1 system with no issue. Just give it 110v power and some kind of audio - separate of course.
A:AnswerDepends on how good your stereo is, do you have a direct sub out on the stereo? then I would connect it to the stereo with RCA cables and run the speakers into the Stereo.
A:AnswerThe adjustment is in the receiver. You may have it turned down too low. The subs get their signal to turn off from the receiver so check that first.