effects of nonlinear air compliance

[Zaph]

The Other John K, (i.e. the smarter one) just wrote a unique spreadsheet detailing the effects of nonlinear driver suspension compliance. I think he intended this to be the primary consideration for dipole design, but this basically shows in a little more detail why I generally prefer larger boxes for subs.

It's a neat sim that can show why placing a large Xmax woofer in a small box can cause distortion.

http://www.musicanddesign.com/driver_box.html

John

 

[ShinOBIWAN]

Thanks John,

This interests me as I've been advocate of build a smallish box using a large radiating area driver and then EQ down to the response you want.

Will try out some of the designs I have done and see how much effect this has on things.

 

[mike.e]

http://www.woodartistry.com/linkwitzlab/images/graphics/air-distortn.gif

http://www.woodartistry.com/linkwitzlab/thor-design.htm

In some situations its definately worth considering.(tiny boxes with huge woofers and huge input power,and high expectations)

I use a jbl2226 on a 200litre ported box,so its not a worry to me.

 

[MarkMcK]

The test of a simulation is not whether it reifies one's prior beliefs but if it accurately predicts what happens and what matters in the world of experience.

As the USA shuttle program manager recently said, "All the wind tunnel tests and fluid dynamics simulations are not worth one test flight."

Simulations . . . be skeptical.

Mark

 

[rcw]

re distortion

Ricard Small coment in his paper on sealed boxs that if the volume displacement becomes more than a few percent of the total volume distortion starts to become significant.

 

[mike.e]

If it wasnt true,it wouldve been disproved by now - probably. With harmonic distortion measurement so easy now.

Comparing reality to simulation is always interesting - how much of an approximation is 'enough'