Revel reintroduces their $10,000 sealed 18" sub

[monkish54]

I found this and figured I'd post it:

This is a really old thread, but I have something to add about the Klippel test and the determination of Xmax. The motor uses two coils and two gaps. When excusrion is low, both coils operate in the gaps for reduced distortion (gaps and coils are in opposing polarity). At high excursion, one cil drives the woofer forward and the other drives the woofer rearward. as soon as one coil leaves its gap, the BL falls, but the other coil is in its gap. This is one speaker for which the XMAX can't be accurately determined by measuriing BL.

Andy Wehmeyer Global Product Line Manager, JBL Car Audio Harman Consumer

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He was referring to the W15GTI MKII and other DD designs.

 

[monkish54]

I personally contacted Harman Luxury Group in hopes they would disclose how Xmax is determined. Not only did a Harman ENGINEER retun my email, he gave me a more in depth explanation than I could have asked for. I will ask if I can reproduce the email on forum, but I will tell you this: Harman uses, what I consider, the best technique for determining xmax there is...

It is certainly not simply coil overhang.

I love Harman....