Ultimate speaker drivers?

[richidoo]

http://www.hqspeaker.com/

Check out the active products

Wolf von Langa

[rollo]

   Wow. interesting stuff. Surely a speaker builders catch of the day. So , has the nervosa begun ? 


charles

[richidoo]

Always! 

[Carlman]

I get the feeling I will be looking at a photo much like this one, many years from now... but with Rich in his garage...

[richidoo]

Let's hope AN is still around then for me to blog about it! 

[Maxamillion]

I'm thinking that doped and patterned graphene sheets as planar diaphragms will be the ultimate speaker drivers. ONE ATOM THICK sheets will have near zero mass, and the conductive/insulating areas of the sheets can be made integral to them, instead of glued on as in modern planars.

Transient response will be perfect.

[Carlman]

How can a speaker move air if it has no mass?

[Maxamillion]

As with all planars, it will be moved back and forth by the forces of attraction and repulsion relative to magnets arrayed in front and back of the diaphragm. Those forces move the air.

The goal with planars has always been to get the diaphragm as thin and light as possible - any mass of the diaphragm itself means that some energy is consumed just moving the diaphragm instead of moving air; that equals lost detail. Kapton diaphragms are very low mass, but a 1 mil thick diaphragm is still thousands of atoms thick!

On top of it's thinness, graphene is also said to be the most conductive material known and the strongest material ever measured, and has excellent thermal conductivity. Great combination!

.

[Maxamillion]

Here's a story about some Korean researchers who have developed a graphene speaker, but their work involves depositing graphene on a PVDF film, so the graphene is functioning only as the electrodes. It works via piezoelectric effect of the PVDF so it doesn't use magnets like most planars.

Once folks figure out how to make large graphene sheets cheaply, why not dispose of the PVDF and use the graphene itself, doped and patterned into conductive and non-conductive regions, in a typical planar arrangement? Still a ways off, but possible, I'd say.

http://www.graphene-info.com/graphene-based-speaker-developed-korea

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[Maxamillion]

Here's another example where a team of Chinese researchers has made a thermo-acoustic speaker from graphene by exploiting its ability to heat and cool extremely rapidly.

http://www.nature.com/am/journal/2011/201109/full/am2011157a.html

All sorts of possibilities with this stuff.

[mgalusha]

Did you get any pricing info Rich? Love to play with some field coil powered 416's. 

[Vapor1]

How can a speaker move air if it has no mass?

Thunder sure makes a lot of noise when lightning has no mass ...

Those drivers are worth watching for sure.  After quite a long time of testing and evaluating through listening (not just with a microphone) just about every high end driver made, I've come to the conclusion that we're in many cases focused on the wrong things.  I'll take low energy storage as measured with something like a burst/decay over .1% THD ... and my correlations are that drivers with very high motor force, low moving mass, and very compliant suspensions give me the sound I want.  These drivers look to be geared in that direction.  My only concern is there's TOO little moving mass, which once you cross that point means a poorly behaved cone.  Until somebody manufacturers a cone of buckyballs or carbon nanotubes, there is a point where too light of a cone in order to reach a sensitivity spec is putting the cart before the horse. 

[richidoo]

Did you get any pricing info Rich? Love to play with some field coil powered 416's. 

My friend from Switzerland who introduced me to these speakers says the A1000 costs 1540 Euros.  Chump change compared to Feastrex!.. 

It sure would be fun to hear them playing to their potential.

[DaveC]

How can a speaker move air if it has no mass?

Thunder sure makes a lot of noise when lightning has no mass ...

Those drivers are worth watching for sure.  After quite a long time of testing and evaluating through listening (not just with a microphone) just about every high end driver made, I've come to the conclusion that we're in many cases focused on the wrong things.  I'll take low energy storage as measured with something like a burst/decay over .1% THD ... and my correlations are that drivers with very high motor force, low moving mass, and very compliant suspensions give me the sound I want.  These drivers look to be geared in that direction.  My only concern is there's TOO little moving mass, which once you cross that point means a poorly behaved cone.  Until somebody manufacturers a cone of buckyballs or carbon nanotubes, there is a point where too light of a cone in order to reach a sensitivity spec is putting the cart before the horse. 

Yup, check out Omega's new 4.5" single driver... low mass, big motor, compliant suspension... it's pretty amazing. The cone weight is a good compromise, it does break up rather than get shouty, but only at reasonably high volumes.

[jimbones]

How can a speaker move air if it has no mass?

Thunder sure makes a lot of noise when lightning has no mass ...

Those drivers are worth watching for sure.  After quite a long time of testing and evaluating through listening (not just with a microphone) just about every high end driver made, I've come to the conclusion that we're in many cases focused on the wrong things.  I'll take low energy storage as measured with something like a burst/decay over .1% THD ... and my correlations are that drivers with very high motor force, low moving mass, and very compliant suspensions give me the sound I want.  These drivers look to be geared in that direction.  My only concern is there's TOO little moving mass, which once you cross that point means a poorly behaved cone.  Until somebody manufacturers a cone of buckyballs or carbon nanotubes, there is a point where too light of a cone in order to reach a sensitivity spec is putting the cart before the horse. 

When I was a kid I used to think the thunder originated from clouds bumping into each other!