Ok, I've been wondering this for a while, and I'm sure I'm not the only one, but what do the sub terms listed below mean? Inductance (Le) Free Air Resonance (Fs) Equivalent Stiffness (Vas) Qms Qes Qts X max X peak Mechanical Excursion (P-P) Gap/Coil Height Displacement (Front Mount) Displacement (rear Mount) Added Volume (reverse Mount) I pulled the words out of my Type-R manual thingy. Thanx for any definitions!

Inductance (Le)- The property of an electric circuit by which an electromotive force is induced in it as the result of a changing magnetic flux.
A circuit element, typically a conducting coil, in which electromotive force is generated by electromagnetic induction
Free Air Resonance (Fs)- Fs or Free Air Resonance is the frequency at which a speaker naturally resonates, like a tuning fork. Sometimes known as ringing response
Equivalent Stiffness (Vas)- Volume Acoustic Suspension. A volume of air in an enclosure that has the same resistance characteristic in acoustic terms as the speaker's suspension in mechanical terms. This is a factor taken into account when designing enclosures. It specifies the optimum internal volume of the enclosure.
Qms- The Q of a speaker driver at its free air resonance considering only its mechanical losses
Qes- The Q of a speaker driver at its free air resonance considering only its electrical losses
Qts- The total resistance in a series or parallel circuit. This takes into account all Driver resistances, both electrical and mechanical.
X max- A measure of a speaker cone's maximum Excursion (back and forth motion) in one direction while still maintaining a linear behavior (moving in a straight line with high precision). This factor is measured in inches or millimeters. Xmax is more precisely defined as the width of the voice coil that extends beyond the front plate plus 15%. This relates to how far the speaker can move in either direction without appreciable distortion.
X peak- ?
Mechanical Excursion (P-P)- ?
Gap/Coil Height- ?
Displacement (Front Mount)- The measurement of cubic volume that an item (such as a speaker or port) takes away from the internal volume of an enclosure. When designing an enclosure, this figure must be added to the enclosure volume . (From the front/rear)
Displacement (rear Mount)^^
Added Volume (reverse Mount)- Volume is obviously the most common word used to specify the control of relative loudness of sounds. It also pertains to the function on many electronic devices that is used to control the loudness.
Also - the measurment of the amount of space enclosed behind a speaker that functions as a resonance chamber.

You can get all this at http://www.electronixwarehouse.com/e...n/glossary.htm

Brian

Thanx man, that helps alot

Mechanical Excursion (P-P)- ?

Mechanical excursion is the physical range of motion that the sub can move through. This is different than x-max, in that this is what the sub can physically do, not what its electrical limitations impose. A sub's physical movement can far exceed it's x-max, it just tends to be so horribly distorted that it's of little value.

I assume that the P-P designates that the spec is given in the peak-to-peak number, meaning that if the sub can move out a half inch, and move in a half inch, that it would have a 1" mechanical excursion value.

The fact that the same sub would probably have an x-max of 10mm helps show why some of these high excursion subs, unless designed properly, are nothing more than a marketing ploy.