Sound Filters to Improve GBA Audio?

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Phaedrus
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Sound Filters to Improve GBA Audio?

Unread post by Phaedrus »

With the new audio filter feature would it be possible to try and improve the GBA audio a bit?

For example I'm playing Mother 3 and the music is great but there is a persistent hum/buzz/hiss that exists on the actual hardware. The music files have been taken from the game and don't have the quality issue on their own, so it's just the way the GBA is using it.

The documentation for the audio filters is a bit light and I'm not much of an audio savvy person, so I'm not sure where to start.

Is this something worth pursuing, or is this not what the audio filters are intended for?

I've tried the LPF example files from here: https://github.com/MiSTer-devel/Main_MiSTer
one of them seems to have no effect on the fuzz and the 2tap and 3tap ones just make everything very quiet.

https://github.com/MiSTer-devel/Main_Mi ... io-Filters

https://forum.starmen.net/forum/Games/M ... zzy-on-VBA

https://earthboundcentral.com/2012/09/f ... r-3-audio/
ExCyber
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Re: Sound Filters to Improve GBA Audio?

Unread post by ExCyber »

The problems allegedly start with the game's music engine losing resolution when it mixes samples. If this is true, I don't think a filter on the output can really fix it; that's basically the audio equivalent of the "zoom and enhance" trope. I'd guess that really fixing it would involve altering the game to mix at a higher quality and then overclocking the CPU to handle the extra work.
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Re: Sound Filters to Improve GBA Audio?

Unread post by Phaedrus »

Well that would be awesome to get something like an MSU option to replace the entire sound track, but I'd just be happy with getting rid of a bit of hiss.
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Re: Sound Filters to Improve GBA Audio?

Unread post by keef »

A more comprehensive set of audio filters is now available in the repository: https://github.com/MiSTer-devel/Filters ... ters_Audio. I'm finding that the arcade filters do a decent job of taming the GBA's hiss.
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Re: Sound Filters to Improve GBA Audio?

Unread post by darksakul »

Keep in mind the actual GBA hardware has no sound processor, all the audio (music and sounds) are handled by the CPU.
The GBA don't even have the proper means to mix sound channels, it was all done on the fly by the CPU.

There no way to place a filter on a internal design flaw of the original hardware.

Combined with the terrible speaker and built in audio amp the GBA had, you are going to get that terrible noise in the audio.
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Re: Sound Filters to Improve GBA Audio?

Unread post by FoxbatStargazer »

All of this is true but that doesn't make custom filters useless. It's the same as noise reduction applied to film media (or hell adaptive de-interlacing), might convey the recorded medium less accurately but still be more pleasing to audiences. As long as its' not overdone anyway.
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Re: Sound Filters to Improve GBA Audio?

Unread post by darksakul »

Thing is for me the MiSTer without the stock Audio Amp and terrible speaker sounded better than the the actual hand held.
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Re: Sound Filters to Improve GBA Audio?

Unread post by aberu »

Personally I use the SNES filter and it sounds better to me.
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