Plopping en cracking sound while switching frequencies

Es gibt 1 Antwort in diesem Thema, welches 471 mal aufgerufen wurde. Der letzte Beitrag (22. November 2020 um 10:26) ist von DutchGuy.

  • Hello,

    I don't know if this is the right forum for this question? So moderator feel free to replace it.

    For a game I am making for the C64 in assembler I wanted to add some music. So I converted a midi file to CSV (midicsv.exe) and using a spreadsheet I exported the two tracks I needed and the correct midinotes

    Using a note table with the frequencies and duration and the IRQ for timing I made a ASM procedure for it based on the procedure Melody from the Bitte melde dich an, um diesen Link zu sehen., (you can look it up page 339)

    Everything is ok and it plays a nice tune using voice 1 (saw) and voice 3 (tri)

    The only problem I have is that sometimes you can hear a slight plopping and sometimes a slight cracking sound when voices are stopped or started

    or frequencies are changed.

    Is there something I do wrong? Should I first silence the SID with SIDVOL regsiter before switching voices and/or frequencies? It doesn't seem to matter much, I tried it.

    Is this a well known effect for the SID or am I the only one that has ever encounter this?

    Or is it my emulator CCS64 that is causing it?

    The timing is in 1/8ths and when commenting out all other procedures in the main-loop, so only playing music, it is sometimes still there, a slight plopping/cracking sound.

    Someone with hands on experience and some pointers would be appreciated.

    It is a very slight sound and barely audible but I am quite the perfectionist so it bothers me :)

    With greetings from Holland,

    DutchGuy

    2 Mal editiert, zuletzt von DutchGuy (10. November 2020 um 16:31)

  • Follow-up: I have tested and tweaked some things. Setting frequency ow&high to zero for short times for voice cut-off, works way better than constant ungating of the voice.

    And when I test the music on TheC64Maxi I don't have a problem at all and it sounds great. It is only a bit audible on CCS64 so no big deal.

    Within a few days I will be able to test it on a real C64 (thank to Bitte melde dich an, um diesen Link zu sehen.) so I can hear what the sound is like. I will keep you posted!

    Einmal editiert, zuletzt von DutchGuy (22. November 2020 um 10:48)