I think its actually software cause different games use different number of samples but I do agree that the GBA has some great sounds. I've seen people on other forums trashing the GBA sound cause samples tended to sound horrible and they would blame it on the 8bit DAC when in actuality the samples were compressed just to save on space and nothing more. The GBA can actually put out some high quality audio when cartridge space isn't an issue. Its still an issue that still plagues portable consoles but not to as much of an extent as it used to.

What do you mean by CPU power, I thought the samples were controlled via software so their shouldn't be a limit to the amount of samples that could be played at one time. And to answer your question Martin_demsky my fascination came with the difference in sound hardware between the SNES and GBA; originally I thought the GBA had 6 sample channels and that was it, but when I found out that 4 of those channels were legacy channels and the other two were sample-ish channels I was surprised and confused because up till that point I had been working on NES and SNES music and each sound channel could only play one note/sound at a time. That, and trying to find information that's useful and not over my head has sort of fueled my curiosity do to the lack of available information that I can understand without knowing arm assembly.

Even though no one responded to my last post, I hope someone knows something here.

Basically I just wanted to know what the sound limitations of the GBA are and I'm just talking about the (Direct Sound) channels for the most part but in some areas channels 1 through 4 might get mentioned.

Question 1 (this might be the easiest question)
Are the Direct Sound channels considered to be sample channels?

Question 2
What determines the amount of samples that can be played at a single time?

Question 3
What determines the amount of MIDI tracks can be played at a single time?

Question 4
When a sound effect plays why do only certain instruments cut out and not others?

Question 5
What does the note off with Noise do in the Sappy Instrument editor (cause it doesn't seem to do anything when I turn it on or off.)

Thanks in advance for anyone who responds here

Is there a way to control the force of midi pitch bends, like if you were to create a portamento for example. I'm trying to create a GBA music hack and in one of the songs there is this portamento section where note C5 is supposed to make a smooth slide down to G3, but when importing this to sappy a two problems arise.

(The first being that the pitch bend range either stops the portamento before reaching G3 or goes past G3).

(The second problem is that when adjusting the pitch bend range to either a higher or lower value determines how much faster and harsher the portamento sounds, basically when the pitch bend range is set to a higher value like c_v-55 it sounds nice and smooth, the only problem being that the portamento plays for like a second before stopping and doesn't come anywhere close to G3 but when setting it to something like this c_v-30 you can here the steps very clearly and it sounds more like a very nasty glissando then a portamento.)

So is there a way that you can control this through sappy, I know its not the hardware cause with deflemask tracker you can create smooth sounding portamento without any problems for the original Gameboy but when creating the same thing on GBA with sappy it just doesn't work for some reason. Now I'm not sure if this is because of sappy or because of mid2agb but any potential answers on how to fix this problem would be great.

Wow that didn't take me long to figure everything out. I will explain what I did to fix the issue here since tutorials online are mostly for pokemon games. Like I thought there were two pointers; the reason I did not see them sooner is because they were separated somewhat far apart from each other and their was so much code around it, so it was hard to see. A simple solution which makes me feel very stupid right now is having your hex editor find those additional values for you. (SERIOUS FACE PALM RIGHT NOW)   

Anyway I hope this will help someone in the future who's in a similar situation.

Ok so I decided to try to change around music in another rom (Sonic Advance 3) and it worked with no issues so I guess megaman and bass might have two or more song pointers? I'm not entirely sure yet. I did mess around with the rom a little more  and was able to get the music to stop playing but that's all I was able to accomplish, and it wasn't very helpful as I had to replace like 6 lines in the song table with zeros. Oh and their was on in in particular 0006A4E0 that controls all sound I believe; when I replaced that line with zeros it got rid of all sound (even sound effects) for some reason. It's surprising that 9 bytes can control all sound in a rom. Anyway I'm gonna mess around with the rom some more; any and all suggestions are appreciated. If I find a solution I will post it here just in case anyone else has a similar issue with their rom.

I am using sappy to make a music hack of (Megaman And Bass GBA) and for awhile when I was importing tracks I would overwrite the non custom songs header with the custom songs header after running into some issues I don't want to do that, but when I move the songs header somewhere else in the rom the song won't play in game, it will only play in sappy. Any kind of help would be appreciated.