Metal speakers. How are they?


I notice that aluminum and magnesium cones have become very common, including in some high quality systems. What's the story on these things? I am considering purchase of a speaker that has Seas 7-inch magnesium woofers, in MTM configuration.

These speakers will replace Dynaudio Gemini MTM speakers whose little 5" woofers are great, but just won't keep up with my three MG1.6 + SW front speakers. I have contemplated rear subwoofers, but there just is not space. The Dynaudios were used for many years as the high end of a biamped system, and they were fine for that purpose.
eldartford
Materials don't (shouldn't) matter. At an introductory seminar (Rosine Audio -Skokie, IL), Arnie Nudell (founder of Infinity and Genesis speakers) was asked if diamond coated drivers would sound good replied: "Drivers made of horse-shit would sound good if they were linear in their frequency range"...
I respectfully submit that materials DO matter. Metal cones can and do ring and have harsher break-up than (conventional) treated paper. This said, there are excellent metal performers -- the "21" Seas are amongst the best. Best,
Gregm..."Harsher" breakup? The literature says that the drivers do have a resonance that needs to be controlled by crossover design, but that this one relatively easy to deal with peak replaces the multiple resonances that occur with cone breakup with other materials.
Hi:
I've heard the W18E001 woofers in two different speakers that were really excellent. I agree with Greg above that cone materials obviously make a big difference.

http://www.ellisaudio.com/1801.htm
http://www.madisound.com/thor.html

Personally, I think S. Linkwitz plays with a deck with a couple more cards than most of us and here is a nice piece he wrote up on drivers including the W18E001.

http://www.linkwitzlab.com/mid_dist.htm

Cheers
I remain,
Thanks for the good info. Seems as if the SEAS W18E001 is about as good as it gets.