How accurate is GBA core sound? (re: settings to improve quality?)

sofakng
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How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by sofakng »

I haven't used an actual Gameboy Advance for many, many years (if ever?) so I'm not sure how it's supposed to sound, but the GBA sound (with the latest MiSTer core) but it doesn't sound very high quality compared to NES/SNES/Genesis, etc.

Can anybody tell me how accurate the sound is and if there are any settings to improve it?

(Please understand that I'm not criticizing the core at all! I am so incredibly thankful for the hard work of the developers and I'm wondering how close the sound might be, or settings to improve it?)
Storminormin
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by Storminormin »

I don't have an ear for sound accuracy at all, but it sounds about right to me.

The GBA sound chip was not very good, especially compared to the SNES, or even Genesis.
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by Phaedrus »

The GBA wasn't known for it's amazing sound to begin with.
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by FPGAzumSpass »

GBA sound consists of (minimal improved) Gameboy Sound Channels and 8 Bit Sound DMA.
The later one is the thing you usually hear for music and some sound effects, the GBA Channels are mostly used for other sound effects.


In terms of accuracy: the 8bit sound dma is proven to be cycle accurate, thanks to a testrom provided by Gericom (GBArunner2 developer)
So it plays exactly the same data at exactly the same time as the real GBA.
As it's 8 Bit source only, there is not much to be improved.

GB Channels alone have been tested and compared to real GBA via sound capture. (thanks to jorge and others!)

In terms of mixing:
What is known, is that when a game uses full volume for both soundDMA and GB Channels, the SoundDMA is a bit too loud compared to the GB channels.
It's not clear why this is the case, because the mixing is easy and inside the GB channels it works.
Maybe it's only related to the GBA using a very weak DAC.
However, this should not influence the overall sound quality.


So if you have anything that sounds off, please post it here and others may check.
I fear I'm very bad at hearing those differences.
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by mic_ »

when a game uses full volume for both soundDMA and GB Channels, the SoundDMA is a bit too loud compared to the GB channels.
Well, the two DMA channels contribute two thirds of the total output level. Or do you mean they are too loud even after taking that into account?
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by bootsector »

Given how GBA core replicates the horrid sound of world 7 map in Super Mario Advance 4, I would say it's 100% accurate! :lol:

https://github.com/MiSTer-devel/GBA_MiSTer/issues/60
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dano
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by dano »

yeah,the gba sound chip is azz. :x
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by FPGAzumSpass »

mic_ wrote: Fri Jul 10, 2020 8:43 am
when a game uses full volume for both soundDMA and GB Channels, the SoundDMA is a bit too loud compared to the GB channels.
Well, the two DMA channels contribute two thirds of the total output level. Or do you mean they are too loud even after taking that into account?
Yes, Jorge did some recordings, showing ~1db too much for SoundDMA compared to all GB Channels in the recordings of GBA core on Mister vs both real GBA and DS.

As it's really not much, probably not recognizable for most, i have not added some quirk for it.
I still hope someone will find where this comes from.

All adjustments in the registers are multiple of 2 or at least 25/75%, so having something like ~10% more is not possible the way the registers are designed.
sofakng
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by sofakng »

Thanks again so much for all of the information.

Also, a bit off topic but is it normal for the Normmatt BIOS to flash/blink every few seconds? It doesn't happen when I use an official GBA BIOS though.

https://youtu.be/bCmr1H8fwh0

Also, is it possible to stretch the GBA image to fill the CRT? I think I can enable the vga_scaler but then it will scale to the 1080p setting of the HDMI output?
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by FPGAzumSpass »

Normmatts BIOS has a few problems.
That being said, it's great that he wrote it and it works well with 95% of the games.

I am really happy that it exists and can be provided together with the core as an instant solution.
sofakng
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by sofakng »

Oh, absolutely! I'm extremely thankful for his BIOS and all of the hard work. I just wanted to make sure this was a known-issue and not something weird with my setup/configuration?
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by FPGAzumSpass »

If you have flickering in every game, that's not related to Normmatts BIOS.
If you have it only in some games, it may is.

That's all i can say about it.
sofakng
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by sofakng »

Hmmm, I'm using the GBA BIOS so it's fine now, but I think the Normatt BIOS only flickered on the BIOS screen (before I selected a ROM).
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by ZigZag »

sofakng wrote: Sun Jul 12, 2020 2:43 am Hmmm, I'm using the GBA BIOS so it's fine now, but I think the Normatt BIOS only flickered on the BIOS screen (before I selected a ROM).
It flashes white every couple of seconds on my setup, I think it's perfectly Normattl...
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by bluescrn »

Phaedrus wrote: Fri Jul 10, 2020 5:02 am The GBA wasn't known for it's amazing sound to begin with.
There's not a lot of audio hardware: https://www.gamedev.net/tutorials/progr ... t-1-r1823/ - and IIRC, it could be tricky to get glitch-free playback even on real hardware

It usually involved software mixing, with very low bitrate 8-bit samples (due to limited cart space, and most people listening through the little mono internal speaker anyway)
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by TrivikramaDas »

The sound is just as good as the original hardware, but it doesn't have the hum/hiss issues that the real hardware does. I have had AGBs with the De-hum/de-hiss kit that Handheld legend sells, and it doesn't sound as clean even with that as the MiSTer does, especially if you add an amp, even clean amp(I haven't tried the all in one de-hum/de-hiss kit, just the one that's the caps you solder yourself individually). With the Final Fantasy Advanced sound patches the games do sound better, not as good as SNES, but they just won't due to how the GBA handles all it's sound in software over the CPU(other than the z80 sounds, which only a few games use)
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Re: How accurate is GBA core sound? (re: settings to improve quality?)

Unread post by darksakul »

I have both the GBA consolizer as well as a MiSTer and I compared them both to a original GBA as well as a GBA SP.
The GBA consolizer and the MiSTer sounds the same.

With a unmodded GBA (both original and SP), the sound is tinny and there hisses and hums from the cheap speaker and bad audio amp the GBA uses.
Which if you use quality headphones or PC speakers the sound improves over the stock speaker.

So with all that said the MiSTer sounds to me about as close as you can get without that crap GBA speaker.

Keep in mind as what others said above the GBA lacks any sound hardware and relies on the CPU to render sound in software.
So it's no where as good as the SNES.
It is my great regret that we live in an age that is proud of machines that think and suspicious of people who try to.
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