I took a look at the sound board and saw that it was using 220μF capacitors and 100Ω resistors to cancel the DC bias of the analog output. If you work that into the formula, you get a cutoff frequency of about 7.23hz. My earlier estimation of 10.0hz was based on analysis of recorded sound output, but I’m pleased to say that I know the exact value now.
I’m testing a VSU emulator that I wrote for the music project, and implemented the new RC value based on the components I saw wired into the actual device. There’s still some noise in the hardware line and the usual analog oddities, but holy smokes, my output matches almost exactly both for amplitude as well as timing.
Attachments:
I’ve decided that even though I can’t draw good pictures, I’ll just have to find a way to make the game with sucky pictures instead. (-: I mean, really, think of some of the simpler cartoons you’ve seen. Do they not work well even with sucky graphics?
Look at that thing. It’s a circle with a rectangle for a body. If Craig McCracken could make The Powerpuff Girls out of that, then I gosh darn better be able to do something… I’ll have to think on it and see what I come up with.
Guess I’d better start fleshing out the details of the game, then. They look like they’ll come into play sooner than expected.
I’m glad my idea was well-received, even if I couldn’t elaborate on it a whole lot. (-: It means a lot to me!
And I’m a bit conflicted. I’m not really at a point where I can put a lot of time into such a game, so I’m not all that gung-ho about making it in the near future. But if I don’t, then I’ll be sitting here on the lore all by myself thinking, “I bet this would be a powerful narrative if only I could share it with someone.”
So here’s what I’m willing to do… First, ask yourself if you really want the story spoiled up-front, or wait until such a time that the game comes to fruition. To draw a parallel, think of The Sixth Sense, where Bruce Willis’s character was dead the whole time (spoiler alert!). Now imagine if you knew that the first time you saw the movie… If you’re still morbidly curious about whatever this oh-so-amazing plot point is that I keep talking about, shoot me a PM and I’ll tell you.
For everyone else, I’ve got a few more YouTunes links–mostly from my Chiptunes menu–showcasing some of the aesthetics I have in mind:
Mythology/Creation: Alinos #2 – Metroid Prime Hunters
Mood (potential in every moment): Godisregn – Malmen and Zalza
Mood (a fine day for success): Mind of a Dreamer – BeaT
Mood (destiny is what we make of it): Sunstreak – Radix
Mood (the things I want to do): Sunny Hollow – Wiklund
Mythology/Reminiscence: “Wapod” – Kirby’s Adventure Wii
I’m glad you guys are looking forward to it. I’m working on it every day and the scent of done-ness is growing stronger and stronger. (-:
DogP lent his electronics expertise once again to solve an interesting little hardware anomaly I ran into. See, the VSU outputs a digital signal where the minimum sample value is 0 and the maximum, if all six channels are outputting their maximum samples at full volume, happens to be 684. Since no negative samples come out of the unit, the audio streams look something like this:
“Surely,” I thought, “this isn’t actually what gets sent from the unit. It’d fry the speaker!” And sure enough, it didn’t look like it gets sent verbatim to the speakers. I recorded some audio output from the Virtual Boy and noticed the resulting wave form was… well, it kinda curved a bit. Still effectively the same audio, but somehow or other it automatically flexed itself to balance around +0V. So I asked DogP what was going on.
Since I’m somewhat less than a noob in terms of electronics, I had no idea it was a simple matter of something called capacitive coupling, wherein a capacitor and resistor are used to block any constant DC voltage from a signal before passing it onto another circuit. The long and short of it is that it’s an implementation of the simplest-possible high pass filter with a very low cutoff frequency, and the effective result is that it removes the DC offset of a stream.
Fortunately, since this is just a first-order filter where the only wiggle room is the cutoff frequency itself, I was able to implement it in the Java VSU emulator without issue and now my output is effectively identical to the clips I was capturing from the hardware:
So score another point for accuracy in emulation. (-:
I’m feeling particularly artistic this time around. <3
