It's possible/likely that the keyboard (keyboard = the keys and electronics that sense them, not the whole unit) decoder cannot handle more than "n" keys depressed simultaneously, where "n" is what you need to get the polyphony.
Keyboard multiplexing/decoding has always been a limiting factor in low-end synths.
Don't most cheap ones allow you to record in one voice/instrument, then switch to a different voice while playing back the original so that you can "accompany" yourself?
Tim.
I've got this Casio keyboard of the $99 Walmart variety that I got to study chord progressions, since it's got a 100 song bank and a display that gives info on the chord type and voicing, even shows the notes on a keyboard display.
When it plays the songs, it uses some fairly elaborately sequenced arrangements with the midi file data burned onto a chip. However, it occurs to me that you couldn't duplicate the multi-instrumentation and polyphony of the arrangements by actually playing the keyboard.
This leads me to think the keyboard has more capability than they've included buttons for, sort of like stories I've always heard that certain calculators of varying cost all used the same chipset but the more expensive ones just had more buttons. Anyone ever heard of someone "hacking" one of these inexpensive keyboards to exploit these hidden capabilities?
Does it have a MIDI connector? If it does you should be able to get at all the goodies that way.
dPearce Consulting
"Tablehooters" is a great site by a guy dedicated to doing this kind of thing:
He confirms that often the same keyboard sound electronics appear in many different models, just inaccessible from the front panel.
I've wondered how they get the demos sounding so good on these little keyboards too. Nowadays, they probably use the same 256 voice GM sound chip in everything, but on older keyboards I've heard some clever workarounds to get round polyphony/multitimbral limitations. Often things like changing timbre quickly between notes, or, if the sound engine allows it, holding one bass note, changing the timbre with it still sustaining, playing the melody notes, and then changing timbre back for the next bass note. This leads to some wacky arrangements!
This model doesn't but the next model up did.
In that case, I think you're out of luck.
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