Home Forums DIY Amplifiers and Electronics DSP – how, why, troubleshooting, different hardware, etc. Reply To: DSP – how, why, troubleshooting, different hardware, etc.

  • ajc9988

    Member
    June 21, 2022 at 5:54 am

    Once again, where did you get that this is not possible? Can you cite a source? Because from what I understand of the use of crystal oscillators and divisors, this isn’t necessarily true. The processor itself can process whatever data, so long as time is kept. You can hard wire a product to solely use one time, or set divisors possible, and even use multiple crystals to allow for the switching of different sample rates in a product. There is even an asynchronous sample rate converter in CCES for the ADSP-21489.

    Many of these products ignore the science of audio. People think they can hear a difference with higher sample rates. Maybe they can. But older studies showed people could not hear the difference above a certain sample rate: 44.1kHz. But the new high def mastering goes up to 96kHz, 192kHz, 384kHz, or multiples of 44.1kHz. My point is, they push for the 96kHz for marketing to people that believe the more information the better. But, from a computational standpoint, you now have double the samples in the same period, and you now must apply the instructions to that many samples, thereby halving or more than halving the number of instructions that can be used for processing.

    Most likely what people are hearing in remastered content in the higher kHz sample rates is the fact they remastered the entire track with better modern techniques, so that if the audio technician is good, you are going to have a better mastered track than the original. As such, they are hearing other aspects of his or her work and believing it is the sample rate that gave the additional sound fidelity, when in all likelihood, it was better equipment, better speakers with less distortion allowing for clearer playback which then allowed for cleaning up the track better, etc.
    And sure, for some, they may even be able to tell the difference in sample rates. It is like some with TVs being more sensitive to PWM flicker and the rate at which the display refreshes. A majority of people will only recognize it seems smoother, but there are some, including specifically professional e-sports players, that are sensitive enough that they can tell the difference of the frequency refresh rate of a display where a normal person might not be able to. But ears and eyes are also different.

    So my point is, I’d like to know where you came up with the notion that these processors only run 96kHz instructions. If you can tell me about the crystal oscillator setting the master time to only the specific sample rate without being able to set a different divisor in software to then arrive at the sample rate, and that the crystal oscillator value means that the divisor needed to arrive at 48kHz is not available for the software being programmed, I’m all ears. Especially as I did not pull the value of the oscillating crystal yet to backtrack the component to look up the datasheet to check that. But, because that has not yet been shown, I will continue on the assumption it can be set otherwise.