Per this review of the 5.1 set that uses the same speakers I pieced together I'm keeping them set on Small with a 60hz crossover:
http://www.hometheaterhifi.com/books...-receiver.html
If I had higher end receiver with a better amp I could maybe set them to Large, but they definitely don't sound as good on Large with my current receiver (the Onkyo HT-R580) Vs setting them to Small and 60hz (which sounds phenomenal). Also my subwoofer actually does a fairly good job.
In all honesty unless you are able to measure the room or use a SPL device your really just guessing when it comes to bass management. What most people think bass sounds right and what is accurate are generally two different things. After looking at a few of the response curves the towers roll off at 80Hz.
To that end my suggestion would be to up the crossover to 100-120hz (start with 120Hz) for the Andrew Jones speakers. Also if possible move the subwoofer as close to the towers as possible (between them is best).
A crossover is not a brick wall filter. Most pre/receivers have a built in filter of 12dB octave high pass and a fixed 24dB octave low pass.
For example if you set your crossover to 80Hz.
12dB octave highpass = At 80Hz the subwoofer will drop its output by 12dB for every octave higher than 80Hz.
24dB octave low pass = At 80Hz the Speaker will drop its output by 24dB for every octave under 80Hz.
The red curve in this picture is the subwoofer and the blue curve is the speaker.
http://img30.imageshack.us/img30/351...ssover80hz.png
Notice the gap between them, the point in setting a crossover is to make that transition as smooth as possible. Again you can only guess at this point if you cannot measure it.
A 10inch bass-reflex subwoofer such as your should have no trouble going up to 150Hz. It will have trouble under 40Hz, that I can promise you. Therefore your subwoofer's sweet spot is going to be between 40-120Hz.
Bass quality depends on the following;
1. location (different for every room and listener)
2. liters of displacement (size,xmax,watts),
3. room construction (ringing, canceling, modes),
4. phase (alignment of the subwoofer front wave with the speaker front wave)
Slow, muddy, and boomy bass are dependent on these factors not the sound quality of the woofer. Remember the driver only has to move 80 x second to make an 80Hz wave. Therefore timbre matching a subwoofer to speakers is pointless. That is why, in this situation you can lift the crossover of the subwoofer (allowing it to take over its intend passband of 120Hz and under) when paired with speakers. By doing this you will have more impact, less distortion and overall better sound quality.
Another benefit to raising the crossover is that lower frequencies take much a higher voltage to produce. By lifting the crossover you are freeing the receivers amp by removing the more power intensive frequencies to be powered by the subwoofer. This will provide less clipping, less distortion, cleaner sound in the speakers through their intend range.
Hope this helps and wasn't too wordy.