Just a side note:
When the Subwoofer is in front of you, the phase should be set to 0° (zero).
When the Subwoofer is behind you, the phase should be set to 180°.
That is fairly important, as setting it wrong will cancel out the bass.
It is too bad you can't get another set of experienced ears on it, to determine if the speakers really aren't performing, or if your expectations are out of line.
Also, likely there is a knob on the front of your amp marked
'Bass', you are allowed to turn that up.
If you can't get the bass you need with the Bass control tweak upward, then I'm completely baffled. Something definitely isn't right. But I can't say whether is it your speakers, your room, or your expectations.
You are certainly not going to get 'blow the windows out' bass with speakers like this, but it should be more than satisfying given the size and price of the speaker. If it is truly not, then again, I'm mystified. You seem to be doing everything right. So, I'm not sure where to go next.
EDITED:
I had another thought, though you must proceed with caution.
Here are some links to test tones you can play from your computer, or burn to a CD, and test your speakers.
http://www.avforums.com/forums/speakers/925527-audio-test-tones-several-sources.html
Buy using test tones, you can isolate specific frequencies and determine with certainty whether this given frequency is playing or not.
But a word of caution. Start by setting the sound level at a modest comfortable listening level. These continuous test tone cause a lot of heat to build up in the speaker. If you are doing the low frequency sweeps pause for a few seconds every minute to give the speakers time to cool down. Or pause between the sweep tracks.
Now, if you turn it up louder, you can hear both higher and lower frequencies. But the test here isn't how loud can your amp go, but instead, what are the frequencies I can hear at normal comfortable listening levels. Once you establish a normal comfortable listening level, do not change it from there, or you risk damage to your speakers.
Also, have the grill covers off so you can see the speakers. You many see the speaker responding nicely to a given frequency, but still not be able to hear it. That's common. I would recommend, NOT testing at any frequencies below 20hz. And, it is really not necessary to test at any frequencies below 30hz, especially on a blookshelf speaker like yours.
Again, when the tones are playing, move around the room to see if you can hear it better in one location than another.
And, fair warning, proceed with caution. This is a reasonable safe procedure,
IF you use common sense.
Steve/bluewizard