The installation of a powered subwoofer is very simple.

You will first need to plug the power cord of the powered subwoofer to an
electrical socket.

Then you will need to look on the back of the receiver. There are RCA
inputs and outputs. Designate a pair of the RCA outputs to run a pair of
RCA cables to the RCA inputs on the powered subwoofer.

Or you can connect the RCA cables to the T.V.'s left and right RCA outputs
as an alternative.

Once you have done this, turn the power on the unit by pressing the power
switch upward.

At this point the powered subwoofer should be powered on and ready for
use.

You can then adjust the volume and frequency control knobs on the back of
the unit to a desired level of sound.

If your receiver has a designated powered subwoofer output with only one
RCA output, the solution is to purchase a "Y" splitter. This is a RCA
Cable connection with one male end and two female ends.

The one male end connects to your receiver and the two female ends connect
to the pair of RCA cables that connect into the line in inputs on the
powered subwoofer.

You can also run an additional or multiple powered subwoofers simply by
connecting another set of RCA cables from the line output on the first
unit to the line input of the other unit.

* A couple of trouble shooting tips !!!

If you experience a hum when plugging the power cord into an electrical
outlet, it may be an electrical interferance that you are experiencing.
 
A trick to try is to buy an adapter that changes the 3 prong power plug to
a 2 prong on the powered subwoofer.
It should take care of the hum.

For some reason, the ground from the house causes an electrical
interferance. ( Usually of 50hz )

* Another cause of hummning do to electrical interferance.

I would also invest in a quality set of RCA cables that have are shielded
from electrical interference.