An ideal total Q parameter is considered a .7 value. Typically this is what you shoot for with a sealed box design. So you combine the mechanical and electrical compliance of the driver with the added control and compliance of the box to get to that figure.
A driver with a .7 total Qts has achieved that control level without the added need of the air space of a box.
Look at it two ways though. Power needed to put the woofer into motion and stopping force or control of the compliance to bring it back to rest.
The .7 Qts range allows the open baffle driver to be put into motion much like typical sealed box driver. But the changing electrical control of the servo system changes the driver total Q values when the input signal stops. So it adds a lot of additional stopping force much like a driver with a .1 or .15 Qts compliance. So the compliance is really changing as it plays.
Thanks for the answer. But I don't follow it.
I thought the servo is constantly working, measuring both the coil current, and the coil velocity (from the voltage across the sense coil), and deriving an output voltage that corrects the error between these sensed signals and the commanded input signal. And that the closed (servo) loop response, it that of a 2 pole system with the poles located based on the switched position of the amp, not the underlying speaker's pole location. (Then for the OB application, a fixed equalization of 6 dB/oct is applied to account for the gain with increasing freq.)
Where I am going with this is wondering what happens if one uses a DS-800-3 in an OB application? (Why? Well because I already have some.) What would it sound like?
