Well, it's been a while. You'll be glad to know I did well at my study - got through the exams.
I have pretty much given up on tuning the XG synths because they only have a resolution of about 1.3 cents.
So now, as far as music is concerned I have finished my guitar drawings and have some engineers looking at them. As for synths, I think probably I should move onto samplers and look closely how waveforms can be generated to define pitch and timbre etc.........
As for sampling, the first go I had was creating a soundfont. I realised the problem I had with the Creative card is that the Soundfont player only has a resolution of about 1.5 cents. So I went back to the samples and retuned them using the trick you showed me to change the sample rate, using WinHex etc. This works really well, and shows me that the pitch detection in Analyse Task in Tune Smithy is doing something right, because when I analyse the sample and then change the sample rate the detection is within 0.02 of a cent every time! So I created a nylon string guitar bank which you can check out if you wish below.
Unfortunately there are some problems: When I use the Soundfont Synth on the card to play back a sample in the bank, I record this and then analyse it but unfortunately the pitches vary between 0.1 - 0.7 cent. I realized this could be any number of things: the velocity curve actually has an effect on pitch, the audigy card is not playing the sample back correctly; the audigy card could be a wavetable player, thus limited in ability to read samples; the soundfont is not correctly set up: a change in the attack or decay time could affect the overall pitch reading; Tune Smithy is counting waves over time, therefore the time and any vacant space in the recording might effect the result???; and the list goes on.
Still, I believe I'm making progress. The font below demonstrates that in the C4-C5 range the pitch for a just C scale is good to about 0.3 cent. So a few things need to happen in order for me to make this work…..
1) Will need to understand pitch detection, and use best method where possible.
2) Need to understand how the amplitude envelope affects pitch, and the best place to take a pitch reading.
3) Need to create the best loop points in original sample, which because of stupid bit and sampling rates, keep causing glitches in my sound (is it possible to ever get these right?).
4) The analysis should be predominately be done on the sustain portion of the note and/or the loop.
5) Make sure sample player is playing back the sample exactly as-is!
6) An automated process of retuning would really help, i.e. have a sample analysed, looped and ready to go; define it’s pitch range; generate the sample rates for that scale in spreadsheet (done); output file names and sample rates (in .csv format); run as script into wave editor and generate .wavs; import into sample (Vienna) and define ranges.
So, it’s plain to see it’s a lot of work to make a sound bank! I guess where you could help if possible is in letting me do a batch process of analysing pitch and then outputting the fundamental pitches into a format that can be imported into spreadsheet (say excel, .csv). Then the sheet will apply sample rate retunes to file names which can be run through a file editor (I don’t know how to do this yet, WinHex?). That will take care of most of the work.
Oh! I haven’t dismissed Tune Smithy as a Midi interface (it would be really awesome with a continuous pitch wheel, such as an analogue synth) and is great for generating preset scales and midi files.
Look forward to your knowledgeable advice and ideas,
Daniel Luke Ivkovic.Linkback: http://robertinventor.com/smf/index.php?topic=69.msg210#msg210