>Bruce Olson wrote:
>>
>> My ABC2WIN has a nice little button on the tool bar that plays
>> A=440 Hz (verified on a 2 channel oscilloscope with 1 KHz reference
>> square wave on the 2nd channel). Why does my ABC2WIN play that A in a
>> tune at 880 Hz, (and all other notes) an octave too high?
>>
>> Bruce Olson
>>........
>
>Henrik Norbeck's ABCMUS plays the correct frequencies (time the
>highest peaks of the triple sawtooth waveform). Also timing is much
>better than one can do with BASICS Sound command (at least the way
>I've been using it). I presume that everyone knows that BASICs Sound
>command puts a square wave into the computer's speaker.
You'll have to ask Jim Vint for a definitive answer on this, but one
possible explanation is that the player in abc2win is very basic,
and just plays through the PC's internal speaker. It does not attempt
to sound like any real musical instrument. The internal speaker in
most PCs is tiny, and cannot reproduce low frequencies, so it makes
sense to play the tunes an octave higher than written so that the low
notes remain audible. It really makes no musical difference; if you
play a tune on a D whistle you are playing an octave higher than if you
play on a D flute, but it's still the same tune. AbcMus, on the other
hand is a dedicated player program which plays through speakers attached
to the sound card and uses real instrument sounds, so it can (must) use
the correct pitch for the instrument selected.
A more serious difference between the two programs lies in their
interpretation of the tempo (Q:) field. Play a reel with Q:400 on
both programs and compare the results. In abcMus it plays at a brisk
dancing speed, while in PlayQabc it goes like a rocket. If you calculate
how long the tune should take to play you will find that abcMus is
correct.
>[I'm going to try faking BASICs Sound command into giving the right
>timing. Going by the book doesn't work very well.]
Ho ho! Isn't sound programming fun?
Phil Taylor
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