Printable Speakers?
- Thread starter lassoharp
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These are subject to the same limitations as PVDF speakers, the talking balloons. ie can't be anything but toys cos no bass.
The other thin film technology, the NXT stuff, is also similarly limited and has extra quality constraints too. I have this from some of the people who invented and developed the NXT stuff.
The only 2 principles that even in theory allow high quality sound over a wide bandwidth are the moving coil speaker and the constant charge push pull electrostatic. There are good reasons why Rice & Kellog's invention is dominant from dirt cheap to the largest & most expensive.
The other thin film technology, the NXT stuff, is also similarly limited and has extra quality constraints too. I have this from some of the people who invented and developed the NXT stuff.
The only 2 principles that even in theory allow high quality sound over a wide bandwidth are the moving coil speaker and the constant charge push pull electrostatic. There are good reasons why Rice & Kellog's invention is dominant from dirt cheap to the largest & most expensive.
usekgb
Well-known member
Technologies like these work very well in commercial and office environments, where simple background and paging is required. The take up almost no space, and have good enough quality for non-critical listening.
Cheers,
Zach
Cheers,
Zach
> The only 2 principles that even in theory allow high quality sound over a wide bandwidth are the moving coil speaker and the constant charge push pull electrostatic.
The electrostatic direct driver has real problems with bass versus size. (Electrostat driver on a horn has interesting leverage but I've only seen it once; and all horns have bass/size issues.)
The moving-coil using iron and Cu/Al has VERY limited treble response, falling badly above 200Hz. Any power-engineer would reject it for inefficiency. (Yet it IS the best we can do for most applications.)
> Rice & Kellogg's invention is dominant
They had the clearest-yet insight that the falling top response of the motor can balance the falling bottom response of a reasonable size diaphragm. That gives a speaker which sucks all over, reasonably flat. Their next insight was that the new world of tubes allowed use of a really horrible inefficiency by brute-forcing it with a massive WHOLE WATT of audio power to get perhaps 0.01W of acoustic power. They followed-through with extensive testing of various cone sizes and materials, and leaked the results so that commercial products were on the market before Bell got around to publishing their paper.
R+K did not invent the cone/coil speaker. The paper you cite does not touch Horns except in passing (Kellogg did have a hand in an excellent horn driver).
The electrostatic direct driver has real problems with bass versus size. (Electrostat driver on a horn has interesting leverage but I've only seen it once; and all horns have bass/size issues.)
The moving-coil using iron and Cu/Al has VERY limited treble response, falling badly above 200Hz. Any power-engineer would reject it for inefficiency. (Yet it IS the best we can do for most applications.)
> Rice & Kellogg's invention is dominant
They had the clearest-yet insight that the falling top response of the motor can balance the falling bottom response of a reasonable size diaphragm. That gives a speaker which sucks all over, reasonably flat. Their next insight was that the new world of tubes allowed use of a really horrible inefficiency by brute-forcing it with a massive WHOLE WATT of audio power to get perhaps 0.01W of acoustic power. They followed-through with extensive testing of various cone sizes and materials, and leaked the results so that commercial products were on the market before Bell got around to publishing their paper.
R+K did not invent the cone/coil speaker. The paper you cite does not touch Horns except in passing (Kellogg did have a hand in an excellent horn driver).
Er.rrh! With my speaker designer's hat on .. ALL transduction principles have a bass/size/efficiency equation. The "moving coil" [1] version is well analysed.PRR said:
https://secure.aes.org/forum/pubs/conventions/?elib=2485
Theoretical and Practical Aspects of Loudspeaker Bass Unit Design - Garner & Jackson
That for electrostatics is less well known and there are practical difficulties in achieving the theoretical performance. Electrostatics work best as dipoles. Using them in horns or boxes negates their advantages. But the theoretical possible efficiency of eg ESL63 is about 94dB/2.83V into nominal 8R @ 1m with the same LF response.
The moving coil speaker as we know it is probably the only principle where a single unit can be designed such that in a suitable box, it covers 20-20kHz with good efficiency ... and more importantly, sounds like it does AND sound good! This has been possible since the 60s but it needed Aboriginal elder Neville Thiele to tell us exactly how.
That's not to say this is easy, cheap or sensible to do today. The small R&K size unit to go up to 20kHz means it would be sensible (for power handling) to limit the LF response to about 70Hz but this means you can use a small box. If you use a R&K 1W amplifier, go for 20Hz and a big box.
Actually R&K were the first to realise the implications of bass/size/efficiency. ie to get Bass, you had to reduce sensitivity. They invented Bass response. Before them, all progress was trying to make speakers louder, not better.
The paper was called "Notes on the Development of a New Type of Hornless Loudspeaker". Chester Rice went on to make significant advances in electrostatics, but nothing to equal the seminal R&K. Kellogg forsook audio to found his cornflake empire.
What they set out was the principles of how to get good sound from a moving coil speaker. Reading the original article and their patent shows how modern Thiele-Small pseudo gurus still don't understand stuff that R&K did. Eg, the full-range speaker I suggest above would be about the size of their prototype.
[1] Garner & Jackson applies to any principle that has some sort of 'pistonic' (or semi pistonic) behaviour in a box.
PS Horns have a bass/size/sensitivity Figure of Merit too. It's worse than for ported speakers but better than sealed boxes.
0dbfs
Well-known member
Next up: Tatoo Speakers
Cheers,
jb
Cheers,
jb
usekgb
Well-known member
Kellogg is a distant cousin/uncle of mine. Very strange guy.
Cheers,
Zach
Cheers,
Zach
