Tracking problems and octave jumps - I've tried everything I

The i2M musicport™ MIDI Converter & Hi-Z USB Audio Interface

Tracking problems and octave jumps - I've tried everything I

Postby jsljustin » Mon Dec 17, 2012 2:02 pm

Hi,

I just got the i2m today in the post and was really excited....

but after many hours of frustration and trying everything suggested in the manuals, and trying everything suggested here, I can't get the i2m to track properly.

Basically, I get random notes, or 2 notes really close together (when only playing one) or I get octave jumps (usually an octave down) almost all the time. It seems that my i2m gets into a state every 10 seconds or so where it just plain gets confused, and freaks out and starts going stupid and doing octave jumps, or adding 3 notes when I have only hit one, etc. It is always worse when I try and play more quickly, but it can also happen when I am playing extremely slowly as well. It is at the point where this device is totally unusable, it would be far easier to just use my keyboard as I always have done, and return this device, as I cannot get it to work as advertised.

I tried everything suggested that I could find - I turned the tone knob all the way down, I am using the neck pickup, I tried dampening the strings with my right hand as I was playing. I tried turning the guitar volume down and turning the preamp gain up to compensate (in order to get less ring and sustain in the notes). I looked at all the settings in the software, and one by one tried different things (turning sus and hold on and off, trying the i2m in chromatic mode versus pitch bend mode etc etc), and nothing worked. I still got the ocatve jumps and the random spurious notes.

So I thought maybe it is my guitar (sympathetic resonances, harmonics, slight fret buzz maybe?). So I thought that maybe a solution would be to use the velocity filter. I mean, if it is an issue with my guitar, then having a cutoff volume would hopefully filter out all these quieter notes, the harmonics, the buzz, the resonances etc. So I set the velocity filter to around 90. This was high enough that I had to really hit the strings hard in order to get any midi note detection. But the problem still occurred, just the same as before.

So I am at a loss as to what I can do. Can anyone here tell me why no matter what I do, no matter how cleanly and slowly I play the guitar, no matter what settings I use, I cannot get this i2m to track in any way that is of use? Could it be an issue with the usb connection? For some reason this i2m that I have seems to just freak out for no good reason and I need some help in figuring out why.

Thanks for any help.

Justin
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Re: Tracking problems and octave jumps - I've tried everythi

Postby james » Mon Dec 17, 2012 2:12 pm

Sorry to hear you are having problems. First lets check to see if the i2M itself has problems.

Does the audio from the i2M work correctly? Can you record that without problems? That will let you know if there are USB issues (the same connection is used for audio and MIDI, of course).

Also, to check the MIDI, use the "latency test mode" on the desktop editor to check that this seems stable.

If that's ok, you should be able to play a single string and it should play a stable MIDI note. And this should sustain for a very long time. That will let you check the stability of the input. Make sure no other strings are vibrating when you do this.
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Re: Tracking problems and octave jumps - I've tried everythi

Postby jsljustin » Mon Dec 17, 2012 3:57 pm

Hi James,

thanks for the fast reply. I tried recording some audio - it records audio OK, no glitches. But the i2m asio driver you have to use to record audio from the i2m - well, I couldn't figure out how to set up the asio driver to playback as you record. It was dead silent in my DAW (Presonus Studio One) as I recorded a test part. For some reason?? Anyway, the audio recording works. However, the CPU load whilst I was using the i2m asio driver was around 75-80% which is very high I think, given that when I went back to my standard asio driver to play the track back it was only at around 15% CPU load.

Does that suggest a USB throughput issue? I mean, a CPU load that high - is that indicative of a possible problem?

I did the latency test on the desktop editor - all is fine there.

you should be able to play a single string and it should play a stable MIDI note. And this should sustain for a very long time. That will let you check the stability of the input. Make sure no other strings are vibrating when you do this.

Sometimes I can, sometimes I can't. I was reading a post of someone else who had a similar issue:
http://www.sonuus.com/forum/viewtopic.php?f=19&t=619

And for example, I get the two notes issue as described there. For example, when I play a B note on the 7th fret, top string, I get a B and then quickly after, a C note. Or if I play a D note (10th fret, top string) it plays a D or a Eb in quick succession sometimes. It doesn't seem to be the way I am hitting it, I mute strings, or press harder, I can't seem to predict why or when it will happen. And often then an octave jump occurs. So I decided to check the B note on a tuner, to see if it was outputting a note slightly sharp at the start, and it wasn't. It was dead on the B tuning at the 7th fret. So unless the tuner is less sensitive, or the i2m is more sensitive, it seems to be some issue around the i2m's pitch detection.

I don't know. I'm at a loss as to what to do. If you could suggest anything else James, that would be great. Or what do you think about the high CPU load when recording audio?

Cheers.

Justin
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Re: Tracking problems and octave jumps - I've tried everythi

Postby james » Mon Dec 17, 2012 4:09 pm

I'm not sure about the high CPU load. Maybe it's the ASIO driver having to work hard trying to resample the audio. But honestly, on a the fast computers of nowadays, the CPU load should be barely noticeable. Depending on your software, you can usually record without the ASIO driver, you just might not be able to hear it while you do so.

Are you using the latest i2M firmware? I do have a beta version of firmware that I can send you (PM me your email address). This addresses a possible issue with USB drop-outs -- but it was never proved whether this was actually a problem or not. Might be worth a try anyway.

In chromatic mode, you can sometimes get the "double-note" triggering because the note is first detected initially when it is slightly flat or sharp, then it settles down to sustaining on an adjacent note. This is worse if intonation is not perfect because it doesn't need to be quite as flat or sharp to get to the next note. In pitch-bend mode, that doesn't happen because pitch-bend is used to bend the note to the correct pitch, so you never hear any mis-detection.
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Re: Tracking problems and octave jumps - I've tried everythi

Postby jsljustin » Mon Dec 17, 2012 4:53 pm

Hi James,

I upgraded to the latest firmware as soon as I had installed it, so I'm using the latest.

The thing I don't understand is that it doesn't appear to be an intonation problem. I put new strings on my electric yesterday, and having already read all the docs for the i2m, I knew that the intonation had to be perfect, so I spent an hour earlier setting the intonation perfectly prior to running the i2m for the first time.

But two points, if I may:
1. The i2m was generating a C note right after I was hitting a B note, so I decided to check the tuning at the B note - 7th fret, top E string. The tuner showed me that the pitch was perfect, at least, as far as the tuner's sensitivity goes, it was reading as B, perfectly! So as far as I can guage with the tuner, the pitch outputted by my guitar at the 7th fret is a pure perfectly-in-tune B note.
2. Guitar intonations are never perfect on every fret on every string. No guitar is. Never can be. Laws of physics dictate this as a reality of fretted stringed instruments. This fact has been published, and is the basis of certain novel guitar nuts that reduce the pitch inaccuracies at certain frets on certain strings, and trade off this improvement with slight lossses of pitch accuracy on other frets on other strings. So I would be right in asssuming that the i2m has algorithms or whatever that allow for pitch variation / slight intonation variability anyhow? I would hope that in chromatic mode at least, this would be the case. In pitch bend mode,my understanding is that micro pitch variations are interpreted by the i2m, so it would send any pitch variations, including vibrato, or a fretted note with slight intonation variations, as data. One of the problems I am having is when I use a keyboard or piano VSTi in chromatic mode. It keeps producing wrong notes. It isn't as noticable with a synth part in pitch bend mode, as I checked the midi output in Studio One and the "pitch bend" data gets sent almost immediately after "note on" data, so you can get away with it.

Anyway, I do appreciate your help. I guess I am frustrated that I can't get the results with the i2m that I saw on those youtube videos. :evil:

But I still hope that I'm doing something wrong.

Justin
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Re: Tracking problems and octave jumps - I've tried everythi

Postby james » Fri Dec 21, 2012 12:26 pm

Hi Justin,

You are correct about what you say about intonation. It is important that it is "close" but there are other things going on that mean that intonation can't be perfect on all notes all the time. Depending on how hard you play a note the initial part of the note will not be at the same pitch as the note when it settles down because when you pluck the string, the string is stretched so it's tension increases and it's pitch increases. If you have a tremolo on the guitar, this will also affect what happens. The amount of pressure you put on the strings when you fret the note also affects the pitch too. So, by making sure the intonation is good, you have the best chance of staying on the intended note when the above variations are taken into account.

In chromatic mode, you do need to play more precisely because of these small tuning variations. Because the pitch-detection is fast, the initial note may be slightly off-pitch, then settles quickly to the correct pitch. A standard guitar tuner isn't fast enough to detect this, but only detects the stable part after the initial attack.

In pitch-bend mode, you don't have to worry so much because the MIDI note frequency will always match the note frequency of what you play. All of the fast videos you've seen on YouTube are using pitch-bend mode.

Usually, it all comes down to playing technique and listening to what works best with the MIDI conversion. Sometimes it works right away, sometimes you need to practice for a week -- everyone is different.
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Re: Tracking problems and octave jumps - I've tried everythi

Postby drizz » Tue Mar 19, 2013 11:24 pm

Justin,

I am experiencing the exact same issue as you. Can you or anyone else chime in here and let me know if there is a solution?

TIA for any help,

Drizz
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Re: Tracking problems and octave jumps - I've tried everythi

Postby ClothForfun » Tue May 28, 2013 10:35 am

That will let you know if there are USB issues.
http://www.womencostume.co.uk/devil-costumes-c-45_51/
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Re: Tracking problems and octave jumps - I've tried everythi

Postby kissmydool » Thu Jul 11, 2013 1:56 pm

Hi,

I have the same issue with the i2m. Any update please? Tnx
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Re: Tracking problems and octave jumps - I've tried everythi

Postby vywopucak » Thu Mar 26, 2020 12:46 pm

This paper is giving the tracking details and all the issues that are being there to solve. Henceforth you have to develop that does edubirdie actually work and attract the users to use this field.
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