So I have a pair of Audio Array AM-S1 bookshelf speakers, which are 60W speakers (60Hz - 20KHz) and cost me $100. I also have a F&D F210x 2.1 speakers and the subwoofer of this set is 9W (30HZ-130HZ) and cost me $22. Now that the bookshelf pair's specifications are better, I was wondering: if I add a cheap subwoofer to the bookshelf speakers, will it help with the low end, or will it make the output from the bookshelf speakers even worse? Considering the F210x 2.1 is much cheaper and uses fewer watts.