i am far from an audio experts, but i think this is right:
i believe the Q value determines the frequency range of the box... higher q values will narrow the frequency range, and opposite for the low...i cant recall which makes the box bigger
now here's what you can do:
most DIY speaker designers aim for a q of 0.707 when designing their enclosures.
i reccomend you take a look at www.diyaudio.com , the people there are VERY knowledgeable adout all things audio, however they usually come across as a bit elite. some of them have homemade equipment that rivals the best commercial components and even betters many of the more store bought crap that the audio industry pedels as "high fidelity".
dont be affraid of them though, just explain what you are doing and that you are trying to learn the ropes as far as enclosure building goes.
edit: i just found this on a speaker definitions page:
Q - the magnification of resonance factor of any resonant device or circuit. A driver with a high Q is more
resonant than one with a low Q.
Qes - the electrical Q of the driver.
Qms - the mechanical Q of the driver.
Qts - the total Q of the driver at Fs. Qts = Qes x Qms/Qes + Qms.
Qtc - value for the damping provided for a driver in a sealed enclosure. Denotes the enclosures ability to
control the driver response at resonance. Qtc = 0.707 is the optimum value for sealed enclosures, providing
flattest response and highest SPL for deep bass extension. Enclosures for this value are often rather large.
Lower Qtc can give even better transient response, down to a Qtc of 0.577 for the best damping and
transients, but the enclosure is usually huge and SPL's are down. A Qtc of 1.0 is a compromise between deep
bass and transient response vs. smaller sized enclosure. Larger subs can go with an even higher Qtc, as their
resonant frequency is often very low, but Qtc's above 1.5 can begin to sound very muddled and boomy, and
sacrifice deep bass extension and transient response for enhanced mid-bass peaks (louder).