Where am I going wrong?

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

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jduffy
Posts: 3
Joined: Fri Dec 19, 2014 11:06 pm

Where am I going wrong?

Post by jduffy »

I get intermittent input, and then, nothing. I have Windows 8, Anvil, midi-ox, loaded the Asio. My goal is input to GuitarPro6. Tonight I see the clipping indicator a lot. I have been able to see midi input in midi-ox. I have been able to use the guitar as input through the i2m into Anvil. When I am viewing composer, I can type individual notes, but no cords. When I record, I pick up a lot of phantom input from somewhere. And then after playing a simple scale and seeing the notes on the screen in Anvil, I saved the file and was able to import it to GuitarPro6. I was able to add a few more notes, but now, during that same session, nothing comes in to ANY of the programs from the guitar.

The first night I had the i2m I wasn't able to get anything except extreme latency and input that was all over the place, and occasionally what I played. Since installing the ASIO, things went better until, nothing. I see possibility to get it all lined out and functioning, but I am so far away from polyphonic and reliable input, I need help. I only have one guitar. It is playing well through the cord into an amp. I have tried multiple usb cords.
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james
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Joined: Fri Jun 06, 2008 8:12 pm

Re: Where am I going wrong?

Post by james »

Does the i2M editor work? This will let you know if the USB connection is reliable.

If this is ok, make sure you have the latest firmware installed in the i2M (you need to download this if you haven't already done so). Then using the editor, enable "latency test mode". This will flash the sonuus logo at the same time as sending MIDI note-on and note-off messages. Use this to check the rest of your system. You should see these notes coming into MIDI-Ox, and into Guitar Pro. If this is ok, then use this mode to debug latency problems. You have to make sure you have small buffer sizes set in your ASIO drivers (256 samples or less).

What other audio devices have you got? What audio device are you using for output?

Watch the video at the end of these FAQs: http://www.sonuus.com/products_i2m_mp_faq.html

Most problems with MIDI conversion are caused by playing technique. And remember, that the i2M is monophonic, not polyphonic, so it won't track chords, only single notes. If you play chords, you will get problems.
jduffy
Posts: 3
Joined: Fri Dec 19, 2014 11:06 pm

Re: Where am I going wrong?

Post by jduffy »

I did update the firmware first day. Sorry I forgot to mention that. I have MS GS Wavetable Synth for output. It is functioning properly. I have done the latency test several times.
I can see the information coming into MIDI-Ox. My buffer size is small about 150ms. I viewed the video again, and have switched to my neck pickup. This seems to have made a difference. I cannot get the computer to fail today like it was the other night.
I can use Anvil in the composer window, to add notation, and use the recording mode to capture the midi data. I captures bends and all well played notes.
GuitarPro6 is accepting notes from the i2M now. I think I have found a limitation of that program. It accepts notes only on the E string today. That is most likely not a Sonuus problem.

No other audio devices as input other than the built in microphone.
I was hoping that by playing a chord i2M would capture the notes, and then I could go back to the score and combine them into a true cord.

Let me work with it further, to see if I can get my technique and understanding of the device and the programs I am using into a workflow.
jduffy
Posts: 3
Joined: Fri Dec 19, 2014 11:06 pm

Re: Where am I going wrong?

Post by jduffy »

I think I have it. In GuitarPro6, when choosing Midi input, there is a checkbox for midi guitar. I had that checked and that seems to be an error on my part. After unchecking that box I get input from all strings. My mind was telling me that my Sonuus + my guitar = midi guitar. That is not the case.

I still need to work with GuitarPro6 more. At this point I am only getting notes coming in at the time value I have selected. It is not reading the value of the note as played and entering the correct time value for the notes. That is leaving me with editing notes and adding cords. If you have any advice, it would be appreciated.

To close this topic, I will say that the Sonuus works! I still have a lot to tweaking to get everything into a more efficient workflow. But that is playing style, and merging other software capabilities with the Sonuus.
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james
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Joined: Fri Jun 06, 2008 8:12 pm

Re: Where am I going wrong?

Post by james »

Ah yes, when you select "MIDI guitar" in Guitar Pro it thinks you have connected a MIDI guitar that knows which string is which (i.e., a guitar with a hex pickup, or a guitar-like MIDI controller). When you do this, MIDI notes on channel 1 are assumed to be the E string, channel 2 the A string, etc. The i2M can't know which string is which because the signal from all strings are combined into one signal. So it's best to not enable MIDI guitar, as you have found.

It sounds like there is some time quantisation going on. I've not used Guitar Pro for a while, and don't have it installed here so can't check for you. But, I assume there is some quantise-to-beat, or snap-to-beat setting enabled.

Guitar pro ignores pitch-bend. If the i2M detects a note slightly sharp or flat (which can happen due to intonation or tuning variations, or just plucking the string heavily) it will pitch-bend it back to the correct note. This happens so quickly, you can't hear it. But if pitch-bend is ignored, it will appear like a wrong note. Enabling chromatic mode will prevent this, but in this case you might get a double-note: the first one, then the corrected one. This can easily be edited by looking for notes very close to each other. This will be easier to fix than looking for wrong notes that haven't been "corrected" because pitch-bend is ignored.

You said buffer size is 150ms... that is a long time, and a lot of latency. Ideally, you want it less than 10ms (256 samples at 44100Hz sample rate = 5.8ms). Are you using the i2M ASIO driver, and a "chained output" on this ASIO driver? What buffer sizes are you using?
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