Well, what I'm trying to understand here is, and I believe everybody else is also, how can you compare a $.45 Cristal "record player" cartridge, to a 80 to $200 moving coil or moving magnet, and/or electret (yup, I had one from micro acoustics and it did not suffer the inductive dilemma that moving coil and moving magnet cartridges had. Unfortunately no longer available) professional cartridges from Shure, Stanton, Ortfon and others?
I can tell you, I remember the RCA encoded Quadraphonic disks, back in the mid-1970s. Those particular disks were encoded with a 19kHz subcarrier frequency and were true 4 Channel vinyl disks. Not to be confused with the CBS "QS" and Sansui "SQ" matrix process which weren't really Quadraphonic disks. Unfortunately, even with some of the best cartridges and styli, after repeated playings, the 19kHz subcarrier would get weak and so the decoder could not detect the subcarrier frequency to decode the additional 2 channels (the process is similar to FM stereo which utilizes a 38kHz subcarrier frequency). It worked but the process necessitated an overall lower program record level, which contributed to surface noise and a general lower signal-to-noise ratio. It did require a cartridge/stylus that had an extended frequency response to begin with. Not something you get from a crystal cartridge. But it still only had to make it to 20kHz.
And we are talking PCM or pulse code modulation for audio, not to be confused with the analog FSK (frequency shift keying) once used with analog tape machines (think Radio Shaft cassettes used to store data with and some of our earliest computers utilized some Ampex's which were used and were in fact FM or frequency modulated recorders, such as the 306's that were not appropriate for audio use since they recorded at full saturation and frequency response was narrow).
Yes, we understand that you don't understand and we are trying our best to answer questions for you that have no real bearing on how or why one should give a crap about your questions since they are really a non sequitur when it comes to audio understanding.
And so the bottom line is, moving magnet and moving coil cartridges are already wide bandwidth devices that have little trouble making it to 20kHz. Crystal cartridges are a much older technology and quite frankly, not up to snuff in any professional application anymore but they did back in the 1940s and fifties, since that's all there was. We don't have to settle for Crystal cartridges, Crystal microphones, carbon microphones anymore, but we did for the first half of the 20th century.
The frequency response of vinyl is limited by physics. No, they don't go much beyond 20kHz because the disk mastering process involves "high-frequency preemphasis". Meaning that high frequencies are significantly boosted during the lacquer/vinyl cutting process. This was done originally as an early form of noise reduction. So if you boost high frequencies when you record, you can roll off the high frequencies on playback, thus lowering signal to noise, to a more acceptable level. This is the technique used with vinyl discs, every type of tape recorder, and FM and television broadcasts. So bandwidth is frequency limited and at 20kHz to prevent problems. Reciprocal boosting and cutting as it is known requires that one rethink the recording and playback process. Provisions to deal with this will put in place and have remained so throughout time. In this process of the high frequency boosting, great care is taken with the use of high frequency limiters to prevent a nasty forum of distortion that became known as splatter from excessive sibelence and other high-frequency content. So in addition to the high-frequency boosting, roll off filters were also incorporated so as to restrict the high-frequency response. And that's why your question is a non sequitur when it comes to audio on vinyl.
What planet did you say you were from again?
Ms. Remy Ann David
