Question

Cone displacement rises above X-Max. Is it a deal breaker?

When modeling a speaker, under what conditions if any can Cone Displacement surpass X-Max? When displacement surpasses X-Max, is my design garbage?

Is limiting power to the driver an acceptable solution?

Attached is an extreme example.

Pyle PLPW8D

Pyle PLPW8D

Fs: 46.2 Hz, Vas: 20.7l, Qts: 0.59

Pyle PLPW8D

Vented

Vented, Vb: 71.5l, Fb: 31.5Hz

Thank you

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Yes, it is. This is definitely not good. But you can try to reduce rated power(by default in the field PE placed max power of the speaker) 

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+63 vpeti89

10 Aug 2019, 18:55

Or try to design a 4th order bandpass and optimize it for the speakers Xmax like me: https://speakerboxlite.com/subwoofers/monacor-raptor-6- at user projects is my design, in Graphs the blue line is the bandpass box, the other 2 are just for comparison - a sealed and a ported box.

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Thanks for the tip Vpeti89. I just finished building my first sub (ported). I will investigate using a 4th order design next. Xmax is the limiting factor in most of the boxes I have been simulating. I have been using ultra cheep drivers.

SpeakerBoxLite makes it incredibly easy to simulate and optimise designs. Am I the only one blown away by what SpeakerBoxLite can do? and for free!

No problem :) . The other thing, maybe I accidentally found the Xmech parameter for the JBL CS1214 speaker and I created a test project. Here on Speaker Box Lite the Xmax=12.1mm, but JBL wrote in an PDF document that the Xmax=21mm. So in my opinion 12.1mm is that excursion where is no distortion and 21mm is that excursion where the speaker starts bottoming out. I dont know that am I right or not, just I tryed to design an 6th order bandpass box for 21mm excursion for this speaker, because for 12.1mm is plausible to simulate it, just the box will be not buildable, or it will have no low bass. Here it is: https://speakerboxlite.com/project-info/28199d3bd764600b7a7e39d3b521113ebf15aa8dfbdf08ec93947117c3160d86 . So in my opinion a 6th order bandpass box is plausible to design / build for Xmech (not for Xmax), just front chamber have to be the low-tuned chamber and rear the high tuned, and I advise that the box have to be 1:1 ratio because it will be just too big.

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