Sound effects

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matteus
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Sound effects

Post by matteus » Fri Oct 07, 2016 11:42 am

I'm stumped for how to do these easily with psg and fm. I was wondering if I could get away with pcm?

Hik
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Re: Sound effects

Post by Hik » Fri Oct 07, 2016 6:01 pm

I think it just depends on the game or program you're making. I asked someone over on the Deflemask forum
and they said they use Deflemask for making both music and sound effects for games.

I used GensKmod to have a look at the YM2612 while playing Sonic 3 & Knuckles ,went into the sound test
and the drowning warning sound stops the music so I could more easily tell which channel the game uses
for sound effects. I got a response for most of them on FM channel 5 I think.

You could maybe ask over on the Deflemask forum and see what they say.

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Re: Sound effects

Post by Stef » Fri Oct 07, 2016 6:16 pm

I don't get your question, are you asking if you can do SFX with PCM ?
Edit: misread the question... you want to do PSG/FM SFX,
For PSG it should be "doable", you can easily reserve a PSG channel for that and send the PSG SFX from 68000 while Z80 is handling music.
You can try to design the SFX from deflemask but i don't know how much the output instrument format can be used for that.
For FM imo it's much more tricky as the music driver has to support it... and honestly FM SFX are generally crappy, better to stand with PSG or PCM.

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Re: Sound effects

Post by matteus » Fri Oct 07, 2016 6:26 pm

I wouldn't know where to begin when making these things! For example the selection sound for when someone selects a menu item! Do literally just play a vgm with one note? and how the heck would I do that if a sound track is playing :/

Hik
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Re: Sound effects

Post by Hik » Fri Oct 07, 2016 7:13 pm

matteus wrote:I wouldn't know where to begin when making these things! For example the selection sound for when someone selects a menu item! Do literally just play a vgm with one note? and how the heck would I do that if a sound track is playing :/
Typically I think you reserve a channel for SFX like Stef said. That way the music goes to the other channels while the SFX uses
the "designated" SFX channel. Like I noticed while looking for Sonic Megamix music online that their tracks never seem to touch
FM channel 6 ,so I think they might be using it for sound effects. Anyway it helped me to look it up since it shows the channels.

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Re: Sound effects

Post by r57shell » Sun Oct 09, 2016 1:03 pm

Stef wrote:and honestly FM SFX are generally crappy, better to stand with PSG or PCM.
:shock:
For example all sfx in RRR is FM! (except larry)
Sonic using FM/PSG too (I'm not sure about PSG)
All I can say: if sfx is crappy -> then it's just poor made.
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Re: Sound effects

Post by Stef » Sun Oct 09, 2016 1:10 pm

In fact a lot of game does SFX with FM and while it can be good, almost time it's just not really nice (thinking about Castlevania bloodline for instance).

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Re: Sound effects

Post by matteus » Mon Oct 10, 2016 9:22 pm

It's a bridge I'll cross once I've a game up and running 100% :)

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Re: Sound effects

Post by Sik » Fri Oct 14, 2016 8:20 am

*jumps in* Sound effects? (・ω・ )

This is the one thing Echo does well (it was explicitly designed with sound effects in mind, mostly because a lot of homebrew sound stuff is actually players and your only hope to play sound effects is to have channels that they don't touch). The problem is that Echo isn't really composer friendly due to the complete lack of composing tools... I just wish that YM2612 code wasn't so hard (..;) (in before everybody throws every DLL they can find at me)
Hik wrote:Like I noticed while looking for Sonic Megamix music online that their tracks never seem to touch
FM channel 6 ,so I think they might be using it for sound effects.
That's the PCM channel.

Megamix is using SMPS (like its base game) and SMPS will just mute from the BGM whatever channel gets used by the sound effect, then give them back to the BGM once the sound effect is over. This is how most sound engines work actually. (unless it's GEMS, which does the weird per-note channel allocation thing instead)
Stef wrote:In fact a lot of game does SFX with FM and while it can be good, almost time it's just not really nice (thinking about Castlevania bloodline for instance).
PSG and PCM can sound just as awful just as easily. On top of that, PSG has a limit to what it can do reasonably (there will be a lot of stuff for which it's not suitable), and PCM usually tends to cut out percussion and that's annoying (drums usually mark the rhythm so it's really noticeable when they get interrupted).

If your sound effects feel awful then the problem is with whoever made them. It doesn't matter which channel. Games with awful FM sound effects generally have awful FM music as well.

EDIT: before I forget
r57shell wrote:Sonic using FM/PSG too (I'm not sure about PSG)
The jump sound effect is PSG, same with the beep when pressing a switch (also used in the score tally). Most sound effects are FM or a mix of FM and PSG though, yeah.
Sik is pronounced as "seek", not as "sick".

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Re: Sound effects

Post by Stef » Fri Oct 14, 2016 2:34 pm

Yeah of course you can do sheety SFX with PSG or PCM, but at least for PCM you can do whatever you want.. A lot of game does FM effects just because they did not even tried to get a PCM driver. Thunder Force series has some of the best FM/PSG music but their PCM driver sucks so much they had to interrupt music when playing PCM (weapon voice).
Castlevania has awesome FM only music but honestly the SFX deserved PCM samples (first boss wolf scream just made my heard bleed). And that is true for many games unfortunately... There is also the reason of ROM space but good and optimised PCM SFX for eat that much. At least with PCM you can produce any SFX sound accurately... That was my point. To avoid interrupting beat/drum sound you indeed need to have multiple pcm channel driver.

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Re: Sound effects

Post by Sik » Fri Oct 14, 2016 5:08 pm

Let me see:
  • Takes up more space (lots more actually, due to sound effects being many)
  • Low quality due to low sample rate and getting interrupted by DMA all the time
  • They interrupt drums (and hence rhythm), unless you mix in software, which tends to make the sample rate even worse
I would never suggest using PCM for sound effects outside things that are outright impossible with FM like voices or impact sounds (punches, explosions, etc.). The only exception to the rule would be if you took it further and made music also consist of multichannel PCM, in which case sound effects would be just one more PCM channel.

The logic about FM being inherently bad for sound effects reminds me about Fonzie's (I think?) comment that PSG is only useful to make garbage and the only way to use it is to leave it mute and never touch it again (he also hates PCM percussion by the way, which is why Pier Solar lets you toggle PCM). Don't blame the hardware when the fault is on the sound designer(s).
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Re: Sound effects

Post by Mask of Destiny » Fri Oct 14, 2016 10:44 pm

To be fair, since we're here in the SGDK subforum, the most relevant sound driver is probably Stef's XGM. Since it supports 4 PCM channels with good quality (reasonable sample rate and buffers to avoid jitter during DMA) and the currently available authoring software doesn't support using more than one of those channels for music, PCM sound effects make a lot of sense there. Obviously, size is still a concern though.

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Re: Sound effects

Post by Stef » Sat Oct 15, 2016 5:07 pm

In my case the problem is that i was really traumatize by many game using awful FM SFX. Of course you can use it in some situation (alarm, bell, special event sounding close to an instrument..) but definitely it cannot suit in every case. PCM is a simple but ROM costly solution for sure. And yeah, if you use SGDK then the faster way to go is, i believe, to just use the XGM driver and using PCM SFX. If you really want to go with FM SFX for some reasons, then yeah, Echo would be a better solution as it does provides support for that.

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