Post subject: What sound samplerate is used for Genesis and Atari 7800 ?
Augusto
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Joined: 11/18/2014
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Thanks for read my post. What samplerate is used when emulating Genesis and Atari 7800 ? Console samplerate Genesis is 22 KHZ and if Atari 7800 use TIA that is from Atari 2600 is 31400. If Bizhawk use an resample filter what is the output frequency ? If possible for user change the samplerate ? Thanks.
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I don't think the Genesis runs at 22 KHz.
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Augusto
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Joined: 11/18/2014
Posts: 37
Yes for some games sounds how being more high than 22 KHZ mainly Midnight Resistance and Comix Zone.
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Bizhawk always resamples to 44.1khz. There are no immediate plans to change this. The 7800's natural sampling frequency is about 31khz. Genesis mixes different devices with different clocks in analog. Raw CD audio is 44.1khz, the FM chip is about 50khz or so, and the PSG is much much higher.
Augusto
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Joined: 11/18/2014
Posts: 37
Thanks for reply. Is an surprise for me see that YM2612 is more of 40 KHZ. Sega had droped the high frequency in some consoles revisions ? About sound the original model allways sounds better than others revisions. Now understand that low quality voices in some Genesis games is because Z80 control the DAC and coders avoiding large rom space that not is an issue on SNES because use compressed sound data. God bless you.
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Augusto wrote:
Thanks for reply. Is an surprise for me see that YM2612 is more of 40 KHZ. Sega had droped the high frequency in some consoles revisions ? About sound the original model allways sounds better than others revisions. Now understand that low quality voices in some Genesis games is because Z80 control the DAC and coders avoiding large rom space that not is an issue on SNES because use compressed sound data. God bless you.
Original Genesis models used a circuit that cut acted as a low-pass filter to a fairly narrow band, I forget the exact range. The circuit (and chip) changed in later revisions which shifted the band around a bit, but in general the circuit was never great hence why many people dislike audio on later models if they are used to originals. Any of the FM chips should be able to reproduce a full 22 kHz (aka 44.1 kHz sample rate) with the right circuit attached (see Mega Amp and others like it).