A history question about planar drivers

12-02-10: Mlsstl
In reference to patents, the devil is certainly in the details. I believe that patent law is one of the relatively few official subspecialties in law practice; it requires special authorization to practice before the Patent Office.

I don't know that Audiogon is a particularly authoritative venue to debate the merits of a patent's scope....

As usual, Mlsstl's comments are well put and correct on all counts. I say that as a licensed patent attorney.

FYI, all U.S. patents that have been issued since 1790 can be searched and viewed at the U.S. Patent and Trademark Office website, although the parameters that can be entered into the search fields for patents issued prior to 1976 are very limited.

A search under "Magnepan" returns these patents. I haven't looked at them in any detail, but I suspect that some of their contents will prove relevant to the OP's question.

Regards,
-- Al

Yeah, I already did the search - but when I did the exact same search I only get 7 results instead of 9. There's something odd about that.

Either way, we'd have to know the details to search for the original patents.

The search returns 9 results if you change the setting in the "search years" drop-down box from the default of "1976 to present" to "1790 to present." The default setting returns 7 results, as you found.

Regards,
-- Al

The lawsuit over Magnepan design against Apogee was settled in Magnepans favor. Apogee had to discontinue some line of speakers.. (and also later went out of business, though I do not know if the two are related) But has been resurrected? in Australia? (This info is just from memory so it may be incorrect)
Anyway, The dude from Magnepan was pretty unhappy about the lawsuit, though he felt he needed to protect his design.
I own Magnepan 3.6s I bought new this last Spring.