Doug Sax -LP Mastering guru on LP vs Bluray

quadzilla

doctorcilantro wrote: »

Strange, I'm confused. The low frequencies don't have a lot of gain on the LP due to the RIAA encoding. The lower you go the more attenuated it becomes until 20hz is at -20db right? Watching the VU meters or looking at a flat vinyl transfer, the midrange has the most gain, and you have to set the ADC accordingly to avoid clipping at 1kHz + frequencies.

I have heard they can cut the groove horizontally or vertically, and bass is cut horizontally to avoid mistracking....but is that due to gain, or is it first a function of frequency?

I know some of those +18db test tracks are indeed wide IIRC but I forget the frequency they use for the tracking torture test.

Yes, the RIAA curve reduces the lows while boosting the highs during recording. See http://en.wikipedia.org/wiki/RIAA_equalization for details. That doesn't change groove width being equivalent to volume. After all, the whole point of the RIAA curve was to prevent extremely wide grooves, especially since lower frequencies tend to contain the most energy, which allowed the engineer to fit more music on the LP. At least, this is what I remember from reading about how LP technology works from years ago. I also recall it being similar to magnetic recording, in that the stronger that magnetization, the greater the amplitude during playback.

If I'm wrong, I wish someone would drift by and explain how it does work.

quadzilla

hearingimpared wrote: »

Too bad these fellows who are/were like Edison have to die! There are always replacements but Edison was unique in many ways.

Not the least of which is that he tried to control the movie industry via patents and suing the bejeezus out of anyone that tried to compete with him.

hearingimpared

quadzilla wrote: »

Not the least of which is that he tried to control the movie industry via patents and suing the bejeezus out of anyone that tried to compete with him.

Hey every genius has their quirks and eccentricities! The sure knew how to make money though.:cool:

[Deleted User]

Hello,
Ah, the famous, "Owners of wide range playback equipment should adjust their systems to the RIAA equalization setting for best performance" printed on the bottom of late 50's early 60's records. The problem was that magnetic cutter heads are not constant-amplitude devices, rather they are constant-velocity. This means that if a constant voltage signal is fed to the head the resultant output will have a roll-off characteristic of 6dB per octave as the frequency increases. That, in itself, wouldn't have been a problem as long as magnetic pickups were used, since they have a reverse characteristic, a 6dB rise in response. The result would have been a flat sounding record with no playback EQ needed. But, since the cutting head is reducing the recorded signal so much that by the time high frequencies roll around the recorded groove is close to the size of surface plastic imperfections.
The curious thing is that, at the same time, very early audio enthusiasts were making their own recordings. Most used crystal cutting heads instead of magnetic. Crystal cutting heads have constant-amplitude responses and these early hifi people used crystal playback pickups so no EQ was ever needed. But professional recording studios used magnetic cutting heads so pre-emphasis and the complementary deemphasis is needed. If early audiophiles had been more catered to and the development of crystal recording and playback devices improved we could, now, have a much improved phonograph playing experience.
In fact that is what the strain gauge cartridge does so well. Its playback characteristics can play a record without needing to have any playback correction.
Cheers, Ken

hearingimpared

^^^^ Ken will you marry me? I can at least promise you good home cooked Italian and other cuisines every day!:eek::D