Midi Pattern Generator - Tutorial
The MPG utilizes a 'start point' adjustment to compensate for the variable response times of different midi devices. For a device that is slow to respond to a midi note-on message, move the 'start point' slider to the right. If the device responds quickly, the slider will need to be moved to the left, decreasing the recording delay. Think of it like this: The midi pattern begins playing as soon as the user hits 'render & go'. Then, after a specified time (the 'start point' in milliseconds), the MPG starts recording the audio. The 'loop recording length' slider then determines how long MPG will record. The 'auto set' feature will attempt to estimate the 'start point' by playing a single note and timing how long it takes to 'hear' the note. It will then adjust the 'start point' to make the appropriate compensation for the lag detected. Surprisingly, testing of the 'auto set' feature revealed that the required 'start point' on some computers will remain very constant (+/-1 millisecond), while on others, the setting fluctuated as much as +/-10 milliseconds. If your 'start point' fluctuates every time you try the 'auto set', your equipment is inconsistent and you may have difficulties recording loops.
Note: due to improvements in timing mechanisms, newer versions of MPG will require different 'start point' settings than the older versions.
If you want to set your 'start point' manually, I would suggest using an audio editor to view what is happening. One excellent freeware editor is SAMPLED by Neurodancer.
I'll use SAMPLED in the following examples, although you can use any program capable of editing 16-bit 44.1khz WAV audio. To make the MPG output to a WAV audio file (rather than directly into Tuareg), see the readme2.txt file.
In the following illustration, the loop 'start point' needs to be increased (slider to the right). Notice how there is a block of silence at the beginning of the pattern, and the last note is cut short. The recording delay was too short in this example. Using SAMPLED you can figure the exact amount of correction needed by highlighting the silent area at the beginning and reading it's length in the millisecond display.
In the next illustration, the first note was triggered before the recording began. The recording started too late, so the 'start point' slider needs to be moved to the left (decreasing the recording delay).
In the next example, the 'start point' is set perfectly, and MPG will export loops which will be perfectly syncronized in Tuareg.
Good luck and enjoy!
Greg O'Grady