Re: sound volume on IIe

[mjmahon@aol.com (Michael J. Mahon)]

Ned Ludd wrote:

>Michael J. Mahon <mjmahon@aol.com> wrote:
>
>> Hmm, must not be _my_ "SoftDAC" (DAC522), since it outputs
>> through the speaker.  ;-)
>> 
>> It should not be hard to search for references to the cassette
>> port $C020 and switch it/them to the speaker $C030.  I used
>> to have both options in DAC511, but then it only took one
>> POKE to change.  With DAC522, there are 32 speaker
>> references that would need to be changed, and space was
>> tight, so the stock version works only with the speaker.
>
>Some time ago I modified DAC522 to output to the cassette port and was
>quite impressed with the results. I think it sounds slightly better
>playing through the cassette port on a IIe than it does through the
>headphone jack on a IIgs, though I may be imagining that ;-)
>
><snip> 
>> The advantage of 1-bit sound is that 8 samples fit in a single
>> byte, so the sounds are pretty compact for their length.  The
>> downside is that it sounds terrible compared to even 5-bit
>> sampled sound (shameless plug  ;-).
>
>So far the best results I've had is with 8-bit 11.025 KHz .wav files.
>The only pre-processing required is zap the file fork (if applicable)
>and strip the header (which I seem to think is the first 128 bytes).
>Another useful trick is to run the audio clip through a compressor
>before saving it, this is especially handy for voice samples or anything
>which requires good bass sound.

That's the way I get sampled sounds to my Apple II, too.

I don't even bother to strip the header--I use SOUND.EDITOR
to trim that off.

WRT low ffrequencies, they can easily take up a lot of the
dynamic range of the samples, with all the higher frequencies
just "riding up and down" on a high amplitude bass waveform.

If you _want_ the bass, then that's just fine, but if you're going
to play the sound on a small speaker, you might as well filter
out much of the bass to recover more dynamic range for the
higher frequencies.  The loss of frequencies below 250Hz will
not be noticeable with a speaker that can't reproduce them
anyway, and the sound that is audible will be better.

-michael

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