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Yes, that would be a smart use of half-speed mastering. That would be for CD4 records only (mostly RCA and Elektra titles). SQ and QS did not have a high-frequency carrier, rather they were matrixed systems. -- Tom Fine ----- Original Message ----- From: "Randy A. Riddle" <[log in to unmask]> To: <[log in to unmask]> Sent: Thursday, March 12, 2015 3:21 PM Subject: Re: [ARSCLIST] Decca FFRR "backwards" disk-cutting -- likely a MYTH > 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 >>>>> >>>>> >>> >>> > >