In March of 1973, before an audience similar to the one today, the V15 Type III was introduced. At that time, we presented a study made by Shure engineers that surveyed the range of frequencies and velocities found in the grooves of commercial phonograph records. The data from that study was compiled and graphed as a distribution of measured points shown on the right in Figure 1. The area these points cover represents the total spectrum of signals that challenge the phono cartridge tracking ability. The "hottest" signals are located along the upper edge, particularly at the high frequency end of the distribution, and represent the toughest signals for the cartridge to track.
From this oft-cited paper: High Fidelity Phonograph Cartridge - Technical Seminar | Knowledge Base | Shure Americas
Hmmm, perhaps a reason that T5 compensation should be moved or modified as discussed in the Cartridge Behavior thread.
From this oft-cited paper: High Fidelity Phonograph Cartridge - Technical Seminar | Knowledge Base | Shure Americas
Hmmm, perhaps a reason that T5 compensation should be moved or modified as discussed in the Cartridge Behavior thread.
I will lend you my copy of Maria Callas "Verdi Heroines" == very noisy lead-in and first fifteen seconds. Interesting LP -- she had tremendous control of her diction.
Couldn't we just scroll FFT's and make a probability distribution.
It would also be interesting to create the chart with different tracking.
I built a "universal compensator" based upon an article in Linear Audio "Archival Phono Preamplifier, LA Volume 5" -- for a lot of the old records I've inherited you can only guess at the compensation curve the recording studio used.
The idea was to make multiple samples of orchestral recordings with enough high and low frequency content, and compare to a baseline established with more modern recordings. You could look at the probability distribution to arrive at the appropriate deviation from the modern RIAA curve.
I have one working "universal compensator" which uses an Arduino controller, touch screen display, and three ADI analog switches for resistance and capacitor ladders....but there is very little interest. More of a curiousity I guess. I haven't done the analysis.
This idea appears similar to the procedure Andrew Rose of Pristine Classical uses for restoration of historic classical music recordings. He performs a spectral analysis of a modern recording of the same piece of music, then equalizes the historical recording to create a similar spectral density curve. ( He, of course, employs other tricks such as noise reduction, speed/pitch correction, etc.)
Seems like a sensible approach. I've thought of doing the same to a few recordings that seem "off". I've done a lot of music spectrum analysis and even somewhere have a thread on the subject.
Would you be looking for certain dominant notes that should land on certain frequencies?
I've used a very expensive software that allows for correction note by note, if the speed, wow and flutter are very bad.
Would you be looking for certain dominant notes that should land on certain frequencies?
I've used a very expensive software that allows for correction note by note, if the speed, wow and flutter are very bad.
Cask05 did a thread on how he 'remasters' modern recordings if you recall. I don't agree with everything he does, but do consider a lot of recordings, ancient and modern to have a decidedly squiffy FR that looks like it could be tidied up. However I also fear for my sanity if I go down this path 
. Andrew Rose has admitted in interviews restoration can drive him nearly mad!
. Andrew Rose has admitted in interviews restoration can drive him nearly mad!
It is astounding what a suitably obsessive person with a powerful computer can achieve. I have a number of recordings on the Dutton label that are superb resorations and the likes of Dutton, Andrew Rose and Mark Obert-thorne have my full admiration.
YouTube check out the 'accidental stereo' restorations.
YouTube check out the 'accidental stereo' restorations.
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