Ramtubes 3-1-2019
Here is something to consider. What if we didnt use RIAA or any EQ in making a record. If we recorded a constant voltage sweep from 20 to 20Khz and looked at it under a microscope what might we see? When we played the final product what would a voltmeter connected to the speaker (or elsewhere) indicate from 20 to 20 KHz.
Choose your cutter wisely and state if it is amplitude or Velocity. Even better do both.
In modern times, at least, cutter heads and the vast majority of cartridges are nominally considered to behave as velocity transducers. I believe that you (Roger) attested to that in the deleted thread.
**If** both transducers were to conform to a theoretically ideal model of a velocity transducer, the response of the cutter head (in terms of groove excursion) would fall at 6 db/octave, the response of the cartridge (in terms of output voltage) would rise at 6 db/octave, and the falling response of the cutter head would be cancelled out by the rising response of the cartridge. So in that hypothetical situation, with no equalization having been applied either in the making of the record or in playing it, the voltmeter you referred to would indicate constant voltage from 20 Hz to 20 kHz. And the excursions of the groove on the record, as viewed under a microscope, would decrease in amplitude as frequency increases.
However, Ralph stated toward the end of the deleted thread that the behavior of both transducers differs considerably from those idealized models, and I certainly have no reason to doubt that. I am not in a position to comment, though, on the manner or the degree to which those deviations from idealized behavior would change the results I’ve described for idealized models.
Best regards,
-- Al