Confused...what is Xmax?

[LeofromtheH 10+ year member]

it's when jesus was born, duh!

 

[Relax 10+ year member]

My bad- I interpretted you were placing a large flat sheet of plexi glass or something.

and I agree- if you give plenty of clearance and the surround still hits something, you do have more problems.

 

[CanadianDream 10+ year member]

Actually you have it right. Thought it would be easier to describe it as a solid piece of plexiglass (one of my possible designs) - but more I am thinking in general.

Say even a mid bass woofer in a door install. How do you determine required clearance from the plastic door panel.

So from what everyone is saying (thanks for the replies) the greater of Xsus or Xmech from the apex of the surround + a few mm's should be sufficient. I agree this is not ideal, just what I have to work with.

I also agree though if my speaker was to exceed Xmech and hit the plexiglass/door panel etc. I would have larger problems.

 

[audioholic 5,000+ posts]

Precisely. Passing xmech would mean ripping some part of the suspension in the process, or bottoming out the coil. The good news is you would notice the driver's non-linear distortion long before this threshhold was ever reached.

 

[CanadianDream 10+ year member]

Sweet...learned something today. Thanks guys.

 

[Hundreth 10+ year member]

Precisely. Passing xmech would mean ripping some part of the suspension in the process, or bottoming out the coil. The good news is you would notice the driver's non-linear distortion long before this threshhold was ever reached.

Not so sure about that, some drivers have an xmax that is very close to their xmech.

 

[Warbleed 10+ year member]

Not so sure about that, some drivers have an xmax that is very close to their xmech.

Thats true, some do! While it is far more common for a driver to be motor limited, there are some drivers which are actually limited not by the motor's linearity, but by the suspension. It is less common, and IMO, a more dangerous way to design a driver, since your chances of damaging the driver at or near xmax are much greater vs a design where the suspensions limits grossly exceed the motors, thus making causing mechanical damage to the driver highly unlikely.

 

[audioholic 5,000+ posts]

Not so sure about that, some drivers have an xmax that is very close to their xmech.

That's a good point. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif But even with suspension limited designs, non-linear distoriton usually becomes easily audible before permanent damage starts to occur.

 

[CBFryman2 5,000+ posts]

Not so sure about that, some drivers have an xmax that is very close to their xmech.

x2

A few ''Big Boy" XBL^2 woofers off of the top of my head with the standard 12 spoke cast basket have no more than 5-6mm between Xmax and the cone hitting the basket/spider hitting the top plate. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

The problem is, the power you need to push them that far in anything but below tuning or a large sealed enclosure to overcome the inductance means that your amplifier will be the limiting factor distortion wise, that or you blow the **** thing. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[helotaxi 5,000+ posts]

You don't need to measure from the peak of the surround, but rather from the edge of the cone itself. The peak of the surround isn't going to move, the surround will simply unfold around it. It's the cone that't moving.

 

[CanadianDream 10+ year member]

So, regardless of whether the woofer is motor or suspension limited...by using the GREATER of Xsus or Xmech you will always account for this possibility. Right?

 

[T3mpest 10+ year member]

yes