The carbon microphone was invented in 1878. The BBC used a refined carbon
microphone from the mid-1920s for broadcasting - this was the Marconi-Reisz
'transverse-current' carbon microphone. In the USA, Western Electric
developed the double-button carbon microphone in the early 1920s, but again
this was used for radio broadcasting only as far as I know.

By the mid-1920s, the carbon microphone had been superseded -
technically-speaking - by the stretched-diaphragm condenser microphone,
which was used in collaboration with amplification systems based on
the thermionic valve (invented in 1907 by Lee de Forest). Bell Research
developed the first condenser microphone in 1917 but early types were
unreliable in practical terms. However, by the mid 1920s, improved condenser
models has been introduced and Western Electric used such a microphone in
its early electric recording system.

With the introduction of condenser microphones, the problems of
signal-to-noise ratio and limited frequency response associated with the
carbon microphones were overcome.

The condenser microphone was more-or-less replaced in the 1930s by the
moving coil microphone and then the ribbon microphone, both of which were
relatively small and trouble free.

Whether the Truetone electric recording system used carbon microphones or
condenser microphones I do not know (I strongly suspect the latter to be the
case), but neither would require the employment of acoustic horns!


Nick



2009/7/13 Ron L <lherault@...>

>
>
> I believe the first microphones were carbon granule or carbon button types,
> adapted from telephony. Perhaps in the Truetone system, collecting horns
> were used in front of these marginal microphones. I'm pretty sure the
> microphones used in the WE system were more sophisticated.
>
> Ron L
>
>
> -----Original Message-----
> From: RedHotJazz@yahoogroups.com <RedHotJazz%40yahoogroups.com> [mailto:
> RedHotJazz@yahoogroups.com <RedHotJazz%40yahoogroups.com>] On
> Behalf Of Nick Dellow
> Sent: Monday, July 13, 2009 7:19 AM
> To: RedHotJazz@yahoogroups.com <RedHotJazz%40yahoogroups.com>
> Subject: Re: [RedHotJazz] Re: hot fives and sevens...
>
> Dave, I can't say for certain if a hybrid acoustic-electric system did or
> didn't exist, so I'll have to do some digging. But I'm scratching my head
> trying to fathom the point of such a hybrid! There were some acoustic horn
> recording studios that used electric motor-powered cutting turntables to
> make the wax master, but that is a simple mechanical factor not an acoustic
> one. For the sound in acoustic horns to be converted to electric signals
> there would have to be microphones at the end of the horns, which is
> utterly
> pointless - the microphone(s) could easily be placed in the studio itself
> and the cumbersome and restricting acoustic horns done away with
> altogether!
> I don't think OKeh's Truetone system infringed any copyrights. Indeed, the
> company developed the system in-house in order get round Western Electric's
> copyright! When electrical recordings were introduced, a number of
> companies
> deliberately didn't make a song and dance about them, for several reasons.
> Although both Victor and Columbia started issuing electrical recordings in
> the first half of 1925 (February in the case of Columbia), both companies
> agreed privately to "be quiet" about the new recording breakthrough until
> November 1925, by which time enough electrical repertory would be available
> and the acoustic recordings could then be more or less deleated from the
> catalogues (with some exceptions).
>
> As I said previously, Mark told me that the New York OKeh studios were
> fitted out for Truetone electrical recordings whereas the Chicago OKeh
> studios were not, but they still released the acoustic recordings as being
> "Truetone". It is as straightforward as that (I think!).
>
> Re: Oliver CJB OKehs comparison with H5s, I presume you are listening to
> CDs rather than original 78s? If the former is the case, then the issue is
> obviously clouded by the quality (or otherwise!) of the re-issues.
>
> Nick
>
> 2009/7/13 David Brown <johnhaleysims@...<johnhaleysims%40yahoo.co.uk>
> >
>
> >
> >
> > Nick, does that mean that a hybrid system did not exist ? I still can't
> > find my source but I think it suggested horns with subsequent electric
> > 'amplification' and cutting .
> >
> > The only possible reason I can find for Hibbard to deny Truetone was
> > electric was because it infringed copyright.
> >
> > While listening through the Oliver CJBs for H5 comparison I decided that
> > the
> > Paramounts of December 1923 recorded at Marsh Laboratories have better
> and
> > fuller sound than the OKehs.
> >
> > The Mainspring Press website
> > http://www.mainspringpress.com/marsh_electric.html raises the strong
> > possibility that these were electrics.
> >
> > Dave
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>
> ------------------------------------
>
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>
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