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Missing midi when two identical notes played sequentially on different strings


#1

First let me say, I love this software, and use it live in my solo performances. But I came across this ‘artifact’ and just wondered if it’s a known limitation that might possibly be something that could be improved, or if anyone has any suggestions.
I do some finger picking, and have found that under certain conditions some midi notes were being skipped, delayed or multiple retriggered. I condensed the problem down to the following situation: if I continuously pick an open B at somwhere around 140 bpm, I get a stream of midi notes, no problem. Next, if I play the same B but at the 14th fret on the A string, same rate, I likewise get a reliable sequence of midi notes. However, now if I alternate between each string in turn between the two identical notes (so same overall rate of notes, like a very basic two finger picking), it intermittently misses the 14th fretted B. I assume this is because the open B is still ringing undamped, and the software is finding it difficult to detect the new note being struck in the presence of a still ringing identical note. However, this is a pretty common occurrence in picking where often ‘drone’ a note is being playing. Interestingly, if you move down, and alternate between say the 10th fret (G) and the open B, there is no problem. Move up one fret, and it’s usually ok. Keep moving up and you start to get issues. When you get within one fret either side of the14th (Bb or C), the midi stream gets very erratic, with missed or multiple triggering and even incorrect notes. By the time you get to about the 16th or 17th fret, the issue goes away.

I highlight the problem with the open B and the 14th fret B, but it likewise occurs when any two identical notes are played sequentially on virtually any other strings as far as I can tell, as long as one is still ringing when the other is played. I would suggest it doesn’t occur when you just play the sequence of notes just on one string because the string is momentarily damped when either the pick or your finger hits the string, thus allowing a clear new note to be differentiated?

Details of setup: clean 6 string Ibanez electric signal going directly into my Firewire 24 MKII Phonic mixer, lots of headroom. No Firewire dropouts detected by the driver. Win 7 PC, MG2 either standalone, or in Samplitude 11 DAW. Noise gate adjustment set fairly low (about 20% I’d guess) for good normal playing (chords and single note etc), but in any case, varying this doesn’t seem to affect the issue. Other than this problem, no other issues with MG2, so I believe it’s a real software issue, rather than setup. Maybe I’m expecting too much? Any thoughts?


#2

Retriggering a note is not trivial: it is not easy for a monophonic system. In a polyphonic system it is far more difficult even.
The stuff that prohibits false retriggers may be killing your unisono. The 2 notes are different in their spectrum, MG most likely then thinks it is not a retrigger of the same note.
We’ll take this issue to the next version of our tracker.


#3

Thanks Paul, I can certainly see why this is a challenge to detect. It would be great if you can find some way to address this in the next or future versions, I’m sure it would make a great enhancement to the MG2 capability and tracking.


#4

Ah an update to add here… I actually have two DAWs set up, my Dell M6800 laptop, which I use for live performances with a StarTech Expresscard Firewire adapter, and my trusty ~7 year old Zt desktop in my studio, which uses a soundblaster card with Firewire support, both i7 running Win7, and running with my Phonic Firewire 16 channel mixer, using Samplitude 11. It turns out that the missing notes problem only occurs on the laptop. I’ve just being trying it on my desktop, and it tracks great, very few missing notes, if any. Which is a bit of a PITA, cos I need the MG2 more for live applications, than the studio. Anyway, bottom line is, I don’t think it’s a MG2 issue, more likely some issue in my laptop hardware/software. I have no problems when using the laptop for recording up to 16 channels live (no dropouts detected, or problems with hitting the CPU max) but obviously something is getting screwed up somewhere - my suspicion is the StarTech firewire card. If anyone has any further thoughts or suggestions, I’d appreciate it, but other than that, at least I known MG2 will do what I need it to do and does track ok, given properly working hardware! If I ever manage to isolate the issue, I’ll update further.