I'm having a lot of trouble understanding some of the specs that are put up for higher end subwoofer. For example, Q, SPL, SQ, ect... Anyone know any forums that explain all this or can anyone explain these specs so that I can understand them?
A good start is to click on the 'Basics' information section found in the left column of this page. You'll find most of what you're looking for. Then just sit back and read through the threads on this forum for more information than you bargained for.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Here's a quote from my old boss, Dan Wiggins that helps explain theile/small parameters:
"
There are only 6 fundamental physical parameters of a driver:
Re - the DC resistance of the voice coil (often called DCR). This includes the voice coil and tinsel leads. Measured in Ohms.
Le - the inductance of the voice coil. Usually measured in millihenries, sometimes microhenries.
Sd - surface area of the cone, usually measured in square centimeters.
Cms - compliance/stiffness of the suspension, usually measured in mm/N. That is, the suspension will sag X millimeters per Newton of force (there are ~4.5 Newtons per pound).
Mms - moving mass of the driver. Typically measured in grams.
BL - motor force factor of the driver. Measured in Tm (Tesla-meters) or N/A (Newtons per Ampere). I prefer the latter, because it is much more explicit about the force factor - X Newtons of force for every Amp of current you put through the driver (note that 1 Tm = 1 N/A).
Xmax isn't really a physical parameter of the driver - it's a "side effect" of a given driver design. Note that you can have the same 6 physical parameters, but Xmax values all over the place. And Xmax does not affect any of the derived T/S parameters.
T/S parameters are typically:
Fs: resonant frequency, set by the moving mass and compliance.
Qms: loss of the compliance, set by the Rms (mechanical impedance) of the suspension.
Qes: loss of the motor. Set by Mms, BL, Re, and Cms.
Qts: Q of the driver - combinatiom of Qms and Qes.
Vas: the stiffness of the driver, scaled by the cone size (Cms and Sd)."
Here's a link with more information: https://www.the12volt.com/caraudio/theile.asp
Thanks a lot guys that was a lot of help.
