Carbon nanotube loudspeakers

[Rodeodave]

moderator note: this is the merge of 3 threads on this subject

Could be cool, but could also be THE most annoying thing ever...

http://technology.newscientist.com/a...on-demand.html

[zapnspark]

I thought this was interesting.

http://tinyurl.com/56erj4

ZAP

[Gustava]

And now for something completely different, from Physics Today:
http://blogs.physicstoday.org/update...ml?type=PTFAVE

[thadman]

This could change everything, possibly no more mechanical resonance systems...but thermoacoustic systems

[MisterTwister]

projector screen with layer of this material would be nice
or even better, ipod touch with sound output matching small boombox. or entire rooms' walls ceilings and floor covered with this material for extremely customizable sound.

[sreten]

Hi,

Do not hold your breath ......

Output frequency = double input frequency = half wave rectifier.

Levels are measured with watts of input @ 5cm distance.

1K ohm per square ? note drive voltages are not given.

Thermoacoustic speakers ? yeah right .... they will not blow up .....

Its all drivel folks, and not happening any time soon.

/sreten.

[noah katz]

Fascinating!

It might not be practical, but calling it drivel is extreme.

Perhaps signal processing to halve freq rather than power consuming DC bias.

It would seem to be doomed to inefficiency if it's generating pressure from heat.

What we need is electrostrictive nanotube film to convert electrical energy directly to motion, like PZT's.

[sreten]

Originally posted by noah katz


.... but calling it drivel is extreme ....

Hi,

YMMV, it is not a "magic" frequency doubler,
it is rectification = shed loads of distortion.

A transducer ? yes, A loudspeaker ? drivel .....

/sreten.

[chicks]

A simple solution is to add a direct current bias I0
to the alternating current for driving such CNT loudspeakers.
To achieve this, we use a very simple single transistor
amplifier to drive our CNT loudspeaker, which can reproduce
the input sound wave signals faithfully.

[gedlee]

Efficiency will kill this idea. There is no end of potential sound makers if efficiency is not an issue. But these things will take a lot of power at high voltage to achieve any reasonable levels of output - especially at LF, and lets face it LFs dominate the situation for almost any type of source. DC current modulation solves the linearity problem, but dramatically raises the power requirements.

Somebody will make devices from this and call them revolutionary sound quality. It is inevitable.