X*** question

[JonJT 10+ year member]

What is the difference between Xmax, Xmag, Xsus and Xmech? Anyone?

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[hoss 5,000+ posts]

Xmax = maximum excursion capabilities

Xmag = maximum excursion ability of the magnetic field

Xsus = maximum excursion allowed by suspension

Xmech = mechanical excursion abilities

going off a guess...

 

[squeak9798 5,000+ posts]

Xmax = One way linear excursion capabilities.

Couple of different ways to measure Xmax. One is measure the difference between the length of the coil & the gap and divide that number by 2 (pretty inaccurate method). Another is to consider it to be the lesser of Xmag and Xsus (fairly accurate method). There's more...but those are the two most "common". Just realize that not all Xmax figures are comparable. Sometimes it's like comparing apples to oranges. Depends on the method used.

Xmag = As hoss said; Linear excursion allowed by the magnetic limitations of the motor. Generally considered to be the point at which Bl had dropped to 70% of it's rest value.

Xsus = Linear excursion allowed by the suspension of the driver. Generally considered to be when the compliance of the suspension has decreased to 25% of it's rest value

Xmech = How far the sub can excurt (non-linearly) until mechanical damage occurs. Basically; if you meet Xmech, you'll have a damaged woofer on your hands //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Please make note of the use of the term linear above. That word isn't just thrown in there for fun. It's a vital part of the definitions.

 

[JonJT 10+ year member]

Ok, thank you very much

 

[hoss 5,000+ posts]

thanks squeak, i was posting during class and just guessing as best i could on them //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[PV Audio 5,000+ posts]

all you even need to worry about is xmax, unless you are designing a driver //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[JonJT 10+ year member]

Or if you want to get into an arguement about total driver displacement. Some people use total possible cone movement to calculate total displacement, knowing how to play the numbers game will help shut them down.