SNES audio

Discussion in 'Technical Discussion' started by JaredAFX, Jul 30, 2013.

  1. ICEknight


    Researcher Researcher
    Just wondering, is that what the GBA hardware does when churning out its usual muffled sound? And in that case, wouldn't it be pretty easy for emulator devs to make their GBA emus to sound like those MIDIs+soundfonts that featured a much higher quality?

    Man, what I would give for a GBA emu that allowed for better sample rate and SNES-size expanded view (like some Game Gear emus, even if it won't look too good for many games).
  2. TmEE


    Master of OPL3-SA2/3 Tech Member
    Estonia, Rapla City
    T-04YBSC-A !
    The GBA hardware most likely has a single fixed cutoff lowpass filter, that is set to safely low level so that PWM carrier freq is not heard (much anyway). If you play 32X games you'll hear a constant whine in some games (like Chaotix). It is the carrier freq and it gets more and more audible as sample rate is lowered. Since sample playback is fully CPU powered on 32X and GBA you cannot go too wild or you'll run out of steam for game...
    It becomes a bit hard for emulator to optimize the sound in GBA, because all the emulator knows is the PCM writes... those MIDI+sound fonts and stuff have whole samples to deal with, the actual source data not just the end product. It is hard to make a 22KHz WAV sound good, but if you had all the source data used in that file you can do lot of goodies.
  3. dsrb


    Well, there's a terrible meme going around that the Game Boy has 4 channels of FM, which is just so wrong it's almost painful. So what you thought is, to be fair, quite a bit more reasonable than that. :v:/>/>

    Yeah, my concern is just that people know what the technology is innately, for the sake of having accurate info, which is important as we both know. Once that's out of the way, it's good that you've explained what you meant and how other types of synthesis can be simulated/approximated.

    OT: What was that computer where people used to hack in sample playback by modulating the volume of a really fast square wave? What would that technique be called? Is it technically a form of AM? I'm wondering whether a similar thing might be achievable using sines or other wave shapes. I bet it would sound like ass, though. Actually, the volume would be in logarithmic steps, like the old method of adding squares from the PSG, so that'd make it even less useful. Never mind, I guess... haha.
  4. Blastfrog


    See ya starside. Member
    Commodore 64.

  5. dsrb


    A meme isn't just a picture with Impact text over it. It's any idea that spreads from mind to mind, regardless of how true it is. The false idea that the GB has 4 channels of FM is far too commonly cited and therefore qualifies as a meme. I guess maybe I should have just said 'common misconception' so that, er, I wouldn't invoke the common misconception about what the word meme means.
  6. muteKi


    Fuck it Member
    Actually I woulda said ZX Spectrum, but it's really more a function of the processing hardware driving the sound hardware and so was a familiar technique on basically any PC that didn't have a dedicated PCM output.