carbon fiber cones?

[thoriated]

I wonder what people think of speakers with carbon fiber cones?

It occurred to me today that I could probably construct such a cone (once I make a mold to shape the carbon fabric). The biggest knock I've heard against carbon fiber cones is their break up modes, but it seems to me that I might be able to compensate for that with a resin impregnant that is regarded as having generally good damping characteristics.

The final objective would be to come up with a speaker with an extremely low moving mass while retaining high strength in the cone and high efficiency while not giving up on reasonable power handling.

Anybody have opinions on this?

[jupiterjune]

I built with Audax 100 co's. Yeah, they had a nasty breakup mode that sounded like a snake hissing. I got rid of the breakup (damped it out actually) by applying glue to the cones. But I think it made the cones too heavy.

You might have to play around with sandwiching the cone or using different amounts of resin, but if you are creative and keep trying, I am sure you can come up with a cone that is light and strong.

JJ

[TerryO]

The prototype cones that Dan Wiggins showed me a few years back were pretty neat, it's really too bad they never really made it into distribution. Very strong and light, Dan (a physically imposing man) demo'd them by slamming them against the edge of a countertop, without any resulting damage.

Best Regards,
TerryO

[M50SNIPER]

Yes. I think it is a great material for speakers (subwoofers especially)....not to mention its good for body parts on your car. Durable, light, yet strong and good looking. But I personally think that it would be best for use in drivers 4 inches or bigger in diameter, not so much dome tweeters and anything that won't play mids and lows. But yea it's definitely possible so good luck.

[454Casull]

You'd have to work with an extraordinarily thin pre-preg sheet.

[Few]

If you can find the extremely thin carbon fiber material just mentioned, I'd suggest building the drivers as two layers held together by an adhesive that damps the resonances (as suggested by JJ). That's what is done with the higher end Rockport speaker drivers and their responses look almost textbook perfect---no nasty breakup. I don't think this is going to be an easy diy project, but it would be very cool if you could make it work.

Few

[DaveCan]

I`m with this dude http://www.mother-of-tone.com/speaker.htm

Dave

[planet10]

I'm not generally a bih fan of carbon fibre srivers, but...

The CSS SDX7 is constructed as an air tight later of some sort of plastic with a loose weave of carbon fibre strands. Once i have impregnated the loose strands with puzzlekoat these are very nice woofers, with no seeming breakup (response rolls off nicely at 950 Hz.

dave

[thoriated]

In the 'old days', it seems many 15" drivers had Mms around 40 grams or so, and some modern day guitar speakers also have exceptionally low moving masses, but of course at the cost of reduced power handling.

I'm wondering what would be possible with a carbon fiber cone with a moving mass comparable to these speakers but high enough rigidity to handle at least a hundred watts continuous. I haven't verified this, but doesn't it seem reasonable that about 3db of sensitivity might be gained by reducing the moving mass by half?

If I'm not barking up the wrong woofer, it might be possible to make a good sounding direct radiator using a carbon fiber cone with as much as 104db/w/m sensitivity below the breakup region. I'd call it a 'green' speaker it it can be made that efficient without a significant compromise in SQ.

[tinitus]