Sunday, May 8, 2011
Before we dive into the incredible sounds of the 2A03, I want to link to another example of FM synthesis:
The most obvious thing you may notice is that the quality of the sound is incredibly high compared to the more rudimentary stuff produced by the Mega Drive. As awesome as the YM2612 sounds, there really isn't much comparison. Sadly, however, I still have no idea what they produced that soundtrack's music on.
With that aside, let's dive into the glorious 8-bit sounds that we all know and love produced by the Nintendo Entertainment System!
Fortunately, the sound chip on the NES, the Ricoh 2A03, is quite a bit easier to understand than the Mega Drive's YM2612. It does not use FM synthesis, but instead four simple oscillators to create sound. But what is an oscillator? Well, I'm not going to get too far into the details, but it's basically a rudimentary waveform created by a repeating electronic signal. To visualize, let's look at a square wave:
As you can see, it actually does resemble a series of squares! Why over complicate things, right? Of course, now, you're probably wondering what a square wave actually sounds like. To put it into perspective, the two square wave channels are most commonly used for melodies and harmonies. They have a much greater presence than, say, the triangle wave, which we can see here:
The triangle wave, on the other hand, is used mainly for bass. It has a low, resonating tone, which makes it perfect for the job. But what about the white noise? Well, it's not as easy to visualize:
But that's because it's just a bunch of static. I'm sure you're familiar with white noise, the loud sound you hear when you tune in to an invalid channel on your television. But how could that possibly be of any application? By itself, it isn't, except for certain sound effects. But when you change the rate at which the volume fades out, you can create some very nice percussion!
So those are the four channels that create all of the sounds you heard in NES music. Pretty amazing, right? But I mentioned a sample channel earlier, too. That's the DPCM channel, or differential pulse code modulation. The name is only there to confuse you. It's just a sample channel. Ever wonder how they got the voices into Tecmo Bowl? Well, now you know! On that topic, I recommend checking out the music for the game Journey to Silius. The composer actually loaded bass samples into the DPCM channel instead of just using triangle waves. The result is one awesome soundtrack.
But not everyone was satisfied with only five channels. A few developers actually created their own sound chips to further enhance the audio capabilities of the NES, most notably Konami and their VRC6. The device, which was packaged in certain game cartridges, doubled the amount of channels available for use. Sadly, however, anyone outside of Japan was never able to experience this. The Japanese NES, the Famicom, was the only system that had support for the external sound chips. The localized NES did not. So certain games like Castlevania III didn't feature the audio that the composers intended. Compare the following two songs to hear the difference:
US/European Castlevania III
Japanese Castlevania III
Well, hopefully now you're a bit more knowledgeable about the wonderful chip known as the 2A03! If you're really curious, you should check out the program Famitracker. It's a music making application that emulates the 2A03, allowing you to create NES music right at your computer! Here's a random video I pulled from YouTube that demonstrates this program:
Hope you enjoyed!