is it STEREO ?

[oeai]

hey, i had an idea to make such data backups some time ago and thanks a lot for doing this project,
but i had an idea that if modem has just a mono input, then making it stereo channel can double the data size
so is it stereo? i think it is pretty much easy to make it 2 threads and with some cross error checks going to some Reverb modulation this can widen maybe broadband too?
well, yes i see - num_of_channels parameter, but they got 128-512k through same channel with Adsl, so some modulations or data archiving maybe ? basically cassette sound mostly is better than i got from the phone, that is about quality of my phone as well, but look Reverb means different power of sound and among STEREO there was JOINT-STEREO for mp3, so measuring also power of signal can add more bits per band and changing some technology\algorithms can boost that.
The easy example - your stereo mode is a 2 separate mono channels - it is stereo async mode, but using it stereo-sync mode can add more bits for the same, because you can remove some checks and use some more sophisticated methods to encode data, because you can measure the power of signal. so basically it is 8-16-24 bits, so you can go from 2-3 bits per 20khz = ~60kb to 12-20 easy. So you will need just pick the good data read -bits size and pack all data using it. Actually using delay\reverb you can modulate mono channel too and get same data, but let's say data correction is important and better with stereo.
If we got some stable bands to decode with high resolution bits - we should take it to 32bits and for those, that aren't good and got some errors - there should be some less bits, less important data or more data checks. i mean this can be more complicated, than just 2 threads to encode\decode. i was thinking for about 500-700mb data per cassette, but it depends on many things and just writing analog music sometimes is easier than pack digital data to the same cassette. if that was 1,5-2gb - that would be a cool stuff, i think 320kb mp3 is an equal and max data for the cassette, so packing with same technique can be best way, but it takes 44khz\16bit and there we got 19-22-32khz maybe 12-32-64 bits, 128 maybe? maybe flac \ ogg is better.
look on it as a string on equalizer or you can imagine it not as a string, but as an objects built with few strings - tetris 3d - data map.
i'm not sure on how to use it in windows \ linux, but i know that audacity and lmms has plugins support, uses sdl and can produce sounds in few formats. vst-plugin can be used by almost any sound program.
i am much more musician and thinker, than a programmer, sorry. all musicians needs to pack data, but all programmers too.

[oeai]

Well, let's imagine more.
let's say we got that system counting about 20-30k high resolution waves or more, we can make it as a spectral anaylsis (zx-spectrum) lightwave encoder. each wave we can make as a source of light, because light is the same wave but having more broadband for it, so we get a 20k led image, we can look on it as a matrix of any-color-points or light sources (like a voxel) - so the obstacles of each source between them (reverb effect) will also have info encoded, this way we can encode more info, but it has to have more rules to read and code it. these basics can be taken from optic fiber, i would use some AI on it. it's like qr-code, but more complicated, like a sound-synths using LFO.