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Wasn't there "super-sonic" frequencies on Quadradiscs?  I was thinking
those had to be cut at half speed because they included a 30 kHz carrier -
if you put one on a turntable and slow it down, the carrier tone is clearly
audible.

On Thu, Mar 12, 2015 at 3:10 PM, Tom Fine <[log in to unmask]>
wrote:

> I don't think very many LPs contained "super-sonic" frequencies, because
> everyone rolled off at some point to avoid blowing out the cutterhead. You
> are very correct, though, that it's easier to cut 10kHz than 20kHz at a
> high level, but what music has high levels of 20kHz in the first place? I
> just don't see any big advantage to half-speed cutting, but I should call
> up my friend Stan Ricker and discuss this in-depth before saying more.
>
> For what it's worth, among the major classical LP labels cutting records
> in NY in the first decade of stereophony, it was typical to low-pass around
> 15K, meaning there was a decrease in level down to about 10K. No one tended
> to complain that there's not enough treble on Mercury, RCA and Columbia
> albums of the time. If you didn't low-pass, you used something like a
> Fairchild Conax, which was a relatively fast limiter for high-frequency
> (above 10K) signals. The reason was, it was expensive to blow out Westrex
> cutterheads and they were easily blown out with intense high-frequency
> information. One thing that mystifies me about half-speed cutting is that
> it came into vogue later on, when most people were using Neumann lathes and
> cutterheads. I thought one of the big advantages of Neumann cutterheads was
> that they pretty much solved the problem of blowing up with intense
> high-frequency information. I know that George Piros, who could cut a LOT
> of HF into an LP using a Scully/Westrex system in the early 60's, said he
> could cut even more HF and level "if I turn off the computer" using his
> Neumann lathe at Atlantic Records.
>
> A major test of how much HF you could cut with a circa 1958 Westrex
> cutterhead came with "Persuasive Percussion" by Terry Snyder and Enoch
> Light, the all-time best seller among "Stereo Spectacular" pop records. My
> father told Enoch Light's biographer that he and George blew out "about a
> dozen" cutterheads trying to get acceptable fidelity with the Chinese
> bells. They finally arrived on a compromise that kept the cutterhead from
> blowing up and ended up with a close approximation of Chinese Bells when
> played back with a good cartridge on a light-tracking turntable of the era
> (2g was very light tracking in those days). It was during that time that my
> father got Westrex to customize his cutterheads, making them mechanically
> stiffer (less compliant), so he could use much less electrical feedback and
> more net power from his 200W McIntosh amplifiers. George perfected cutting
> right on the edge of coming out with a trackable record and not blowing up
> too many cutters.
>
> Ironically, now that I wrote that, I think half-speed cutting would have
> been really beneficial in the early stereo days. But not when it was en
> vogue.
>
> -- Tom Fine
>
> ----- Original Message ----- From: "Dave Burnham" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Thursday, March 12, 2015 2:46 PM
>
> Subject: Re: [ARSCLIST] Decca FFRR "backwards" disk-cutting -- likely a
> MYTH
>
>
>  I always thought the advantages of half-speed mastering were in the high
>> frequencies, not the lows; super-sonic frequencies were brought down to
>> sonic frequencies and recorded more easily, but very low frequencies were
>> pushed down into a subsonic range and frequencies in the low teens can be
>> troublesome for tape heads. Also consider that direct to disc recordings
>> are better sounding than any half speed mastered disc and, of course, they
>> can only be recorded at normal speed.
>>
>> db
>>
>> Sent from my iPhone
>>
>>  On Mar 12, 2015, at 8:49 AM, Tom Fine <[log in to unmask]>
>>> wrote:
>>>
>>> I do think they pioneered this, going back to SONAR training equipment
>>> in WWII.
>>>
>>> Speaking of half-speed cutting, I have never understood how this is
>>> pulled off in a modern context, especially with Dolby-encoded master tapes.
>>> I guess it's possible to make the NAB or CCIR tape EQ de-emphasis work at
>>> half-speed, and the RIAA emphasis at the lathe, but doesn't Dolby get
>>> screwed up when frequency bands are lowered?
>>>
>>> Today, I think one can listen to recent LP cuts by Bernie Grundman or
>>> Ryan Smith or Sean Magee and hear that there's no need for half-speed if
>>> the cutting engineer and his cutting chain are top-notch. I've heard
>>> arguments about fitting more bass energy on a disk at half-speed, but again
>>> I can't understand how that's true since the disk will be played back at
>>> full-speed and hence won't track on normal-priced systems if the grooves
>>> are too wide and deep.
>>>
>>> -- Tom Fine
>>>
>>> ----- Original Message ----- From: "Carl Pultz" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Thursday, March 12, 2015 8:18 AM
>>> Subject: Re: [ARSCLIST] Decca FFRR "backwards" disk-cutting -- likely a
>>> MYTH
>>>
>>>
>>>  Decca did do some half-speed cutting - am I remembering that right?
>>>>
>>>> -----Original Message-----
>>>> From: Association for Recorded Sound Discussion List
>>>> [mailto:[log in to unmask]] On Behalf Of Tom Fine
>>>> Sent: Thursday, March 12, 2015 7:57 AM
>>>> To: [log in to unmask]
>>>> Subject: [ARSCLIST] Decca FFRR "backwards" disk-cutting -- likely a MYTH
>>>>
>>>> I asked the folks at Decca Classics, including the guys who just put
>>>> together the excellent new "Mono Years 1944-1956" box set. All of them
>>>> said,
>>>> in essence, no way. The technical guys said it's not possible to cut
>>>> 20-minute LP sides this way and there was no reason to do it, given
>>>> Decca's
>>>> advanced cutting techniques developed during WWII, many of which were
>>>> ported
>>>> over to microgrooves.
>>>> For 78's, they said again there was no reason to cut a disk backwards
>>>> since
>>>> they could easily accomodate FFRR cutting forward like everyone else.
>>>> Unless
>>>> someone can come up with some documentation saying otherwise, I would
>>>> say
>>>> this is a MYTH and should be nipped in the bud here.
>>>>
>>>> -- Tom Fine
>>>>
>>>>
>>
>>