Compression cancellation with dual voice coils

[DanWiggins]

There's an interesting article by Eugene Czerwinski et al in the latest JAES.
There they present the BL product as a function of coil travel. The underhung version was distinctively better.

We've got DUMAX measurements on a variety of drivers: http://www.adireaudio.com/Technical/tech.htm#TECHNICAL REPORTS . Short gap overhung, long gap overhung, underhung, XBL^2, JBLs DDD are all represented. The flattest, widest curves are the Brahma and the JL Audio 10W7.

When I saw it, I thought that it was a pity that I didn't order my (otherwise excellent) woofers with underhung voice-coils (as the manufacturer proposed !). The downside of his proposed version was only a little less x-max and a slightly higher price. Now that I have experience with the excursions I usually encounter the way I usually listen, I'd definitely order them with underhung voice-coil !

BTW: Convection cooling of the coil is increased with underhung construction also and thereby reducing thermal power compression.

Regards

Charles

Check out http://www.adireaudio.com/Files/XBL2TechPaper.pdf for some information about how the different driver approaches compare, with regards to BL flatness and distortion/compression. In fact, it's pretty interesting that the current trend towards long gaps with overhung voicecoils is actually WORSE in terms of linearity as compared to short gap overhungs (and both are worse than underhung, or flat BL designs).

Dan Wiggins
Adire Audio

 

[phase_accurate]

In fact, it's pretty interesting that the current trend towards long gaps with overhung voicecoils is actually WORSE in terms of linearity as compared to short gap overhungs (and both are worse than underhung, or flat BL designs).

That's indeed interesting.
I think my drivers still go under short-gap/long-coil (6mm/25mm). They are excellent anyway. But now that I have a better feeling of the actual excursion needs of mine I think it won't be detrimental to have an underhung driver.


Regards

Charles