T/S parameters... what are they good for?

Q in general is a loss ratio. basically imaging a swingset or pendulum. it will swing back and forth for a long time and at the same rate. this corresponds to a high Q.

ok, so add some friction to the moving parts and they'll slow down. friction converts the energy to heat. this is actual use of energy and eventually the swing will stop. this is lower Q.

take a woofer now. normally it will want to move at a given frequency, and has a Qms related to how much it favors moving in that manner. Qms will show up when you look at a free-air impedance plot. if you use the electomagnet to stop the woofer you can get a signifigantly lower Q, Qts.

from this perspective you can see that a high Q means highly favoring one note, while a low Q means favoring a wide bandwidth. once you port a woofer, you actually intoduce a second Q and F resonant effect. you can use this second resonator to give a boost. the port will have a Q as well, and a low Q port will give a smaller boost, but will do so to more frequencies.


i saw one of my old posts. almost though someone else was pretending to be me...

for high SPL it is beneficial to have high Q values, as a high Q corresponds to low loss.

edit -- this is more of a generalization. i am not saying to look for high Qts speakers.

I really like the Klippel tests published here and, as a noob in this forum, I'd like to thank everyone involved.
jblw10... the question you are asking is not that simple to answer. Your best bet would be to read up about harmonic oscillation and its variants, simple, damped, and forced. As usual, Wikipedia has a succinct writeup. Look up "Harmonic oscillator".
There you will see that the critical amount of damping equates to a total Q of 0.5, although this, in and of itself, is not all there is. You will be needing some understanding of calculus if you want to dig deeper. Q is a qualitative measure of how much energy is lost every time an oscillator completes one full oscillation.
Roughly speaking, a driver is characterized by its own Q, which has an electrical part and a mechanical part. The electrical part is much more significant, because it is the smaller of the two, and is added to the mechanical part in inverse form. Once a driver is mounted to a cavity, its mechanical Q changes because the air in the cavity gets coupled to it. This changes the overall Q, and the new total Q is what now characterises the system's behavior.