Shersta,
To reiterate everyone else, you will not be able to hook up the 2W the way you mentioned. It has high-level inputs only. If you want to use line-level, you would need to go with a V2W. 2W and 2WQ are made for listening to music in a stereo system. The V2w was made for home theater applications.
That being said, I use two 2ws in my stereo/home theater set up and they work great. You don't really need to use a separate LF channel.
To reiterate everyone else, you will not be able to hook up the 2W the way you mentioned. It has high-level inputs only. If you want to use line-level, you would need to go with a V2W. 2W and 2WQ are made for listening to music in a stereo system. The V2w was made for home theater applications.
That being said, I use two 2ws in my stereo/home theater set up and they work great. You don't really need to use a separate LF channel.