1/2 speed cutting not usually so good?


Any mastering engineer or other person in the know care to comment on Bob Ludwig's letter in the March issue of The Absolute Sound where he indicates that 1/2 speed cutting is a trade-off. He says that a cutter head flat to 20Hz is only flat to 40Hz at half speed. In combination with the RIAA cutting curve, Ludwig says that an additional equalization circuit is needed for 1/2 speed cutting that introduces extra ringing and distortion. He concludes: "For some music, half-speed cutting is an advantage, for the majority, probably not."
Perhaps I misunderstand the process. But if I have it right, some other folks including those at Mobile Fidelity may want to provide a different viewpoint.
gpgr4blu
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Co-incidentally, I have been thinking about this issue myself lately; what are the tradeoffs; why aren't more masters cut at half speed? I do not subscribe to AS; is the article available on-sline?
Not all lathes can operate at 16rpm. Certainly speed stability is a much greater issue at the lower speed!

I don't buy the 40Hz thing. Our cutter seems to go down much lower than just 20Hz, as do our electronics.

Seems to me it was Decca in the UK that first started using 1/2 speed mastering as part of their method of controlling cutterhead resonance. Essentially, this put the resonance in the upper part of the last octave, which is beneficial due to the RIAA pre-emphasis (boost at high frequencies); IOW it meant that less amplifier power was needed.

There are indeed tradeoffs!