i2M not tracking well

[mtl777]

I use my i2M with a Strat. It's not tracking well. Even if I just hit one note repeatedly with the same velocity and not too fast, sometimes it tracks the note as an octave lower.

My input level is set at 0 dB and it never clips even if I hit the string hard. I am plugging my guitar direct to the i2M, not using any DI. I have not installed the i2M ASIO driver -- I thought it doesn't matter as I'm only interested in the MIDI which I record in my DAW, and I have better converters (Mytek Stereo96 ADC) if I want to record audio.

What could I possibly be doing wrong? Or am I expecting too much of the i2M? Has anyone compared it with other similar audio-to-MIDI converters such as the Roland GK-2A? How does it compare?

[james]

I use my i2M with a Strat. It's not tracking well. Even if I just hit one note repeatedly with the same velocity and not too fast, sometimes it tracks the note as an octave lower.

The usual cause for a note being played an octave lower is that more than one string is being struck, even if only slightly. Often this isn't a problem, but if the frequencies of the played string and the unintentional string align in a certain way, it can look like a note an octave below has been played.

My input level is set at 0 dB and it never clips even if I hit the string hard. I am plugging my guitar direct to the i2M, not using any DI. I have not installed the i2M ASIO driver -- I thought it doesn't matter as I'm only interested in the MIDI which I record in my DAW, and I have better converters (Mytek Stereo96 ADC) if I want to record audio.

Correct, you don't need the ASIO driver for MIDI. Could the input level be too low? Try increasing the level as much as possible, but so it doesn't clip.

What could I possibly be doing wrong? Or am I expecting too much of the i2M? Has anyone compared it with other similar audio-to-MIDI converters such as the Roland GK-2A? How does it compare?

It is worth recording audio from the i2M (using the standard drivers are fine, you don't need the ASIO unless your application needs this). This will let you check that the audio looks fine and there are no obvious problems with the i2M itself.

I suspect the problem is just that more than one string is being played. Try to damp the other strings more carefully to see if this helps.

We have compared to the Roland systems, and I know others have too. The i2M is faster, often more accurate and tracks pitch-bend much more precisely. However, if multiple strings are played, hexaphonic systems (like Roland) have an advantage because they isolate the signals from each string so you don't get tracking problems when several strings are played at once.

[mtl777]

The usual cause for a note being played an octave lower is that more than one string is being struck, even if only slightly. Often this isn't a problem, but if the frequencies of the played string and the unintentional string align in a certain way, it can look like a note an octave below has been played.

I was testing it by hitting only one string and one note. I held the note without releasing and repeatedly picked on the string, making sure to hit only that string. Sometimes it would play an octave lower. This problem seems to manifest after several hours of playing, not when I have just turned on the computer and connected the i2M. Also there was one instance when I suddenly lost connection -- the Sonuus LED went out.

Correct, you don't need the ASIO driver for MIDI. Could the input level be too low? Try increasing the level as much as possible, but so it doesn't clip.

So installing the ASIO driver wouldn't help at all to improve the MIDI tracking? How does it work? Does the i2M have an internal A-D converter which converts the analog input to digital, which is then followed by a circuit that analyzes the digital audio stream and converts it to MIDI, and then the MIDI and digital audio are transmitted via USB to the computer?

It is worth recording audio from the i2M (using the standard drivers are fine, you don't need the ASIO unless your application needs this). This will let you check that the audio looks fine and there are no obvious problems with the i2M itself.

If I record the audio from the i2M, will I be using its A-D converter (if it has one) and not the excellent converter of my Mytek?

If I install the i2M ASIO driver, will it use an additional IRQ and consume some CPU resources or possibly introduce some conflict and increase the likelihood of dropouts in my already heavily-taxed DAW?

Try to damp the other strings more carefully to see if this helps.

How do I damp the other strings? Seems difficult and distracting.

[james]

How do I damp the other strings? Seems difficult and distracting.

The most common way is to palm-mute. When playing with lots of distortion, it's a very common thing to do because at high-gain even small string oscillations will be very audible.

Of course this may not be your normal technique, and it may be difficult to adapt.

An alternative is to use a muting device, such as the BuzzNut (http://www.shredknowledge.com/index.php ... ew=article). This damps open strings without having to change technique, and it has been tested (and works well) with the i2M.

[mtl777]

The BuzNut looks good. Thanks for the suggestion!

I had some other questions in my 9/9/11 post that I hope you could answer...

The usual cause for a note being played an octave lower is that more than one string is being struck, even if only slightly. Often this isn't a problem, but if the frequencies of the played string and the unintentional string align in a certain way, it can look like a note an octave below has been played.

I was testing it by hitting only one string and one note. I held the note without releasing and repeatedly picked on the string, making sure to hit only that string. Sometimes it would play an octave lower. This problem seems to manifest after several hours of playing, not when I have just turned on the computer and connected the i2M. Also there was one instance when I suddenly lost connection -- the Sonuus LED went out.

Correct, you don't need the ASIO driver for MIDI. Could the input level be too low? Try increasing the level as much as possible, but so it doesn't clip.

So installing the ASIO driver wouldn't help at all to improve the MIDI tracking? How does it work? Does the i2M have an internal A-D converter which converts the analog input to digital, which is then followed by a circuit that analyzes the digital audio stream and converts it to MIDI, and then the MIDI and digital audio are transmitted via USB to the computer?

It is worth recording audio from the i2M (using the standard drivers are fine, you don't need the ASIO unless your application needs this). This will let you check that the audio looks fine and there are no obvious problems with the i2M itself.

If I record the audio from the i2M, will I be using its A-D converter (if it has one) and not the excellent converter of my Mytek?

If I install the i2M ASIO driver, will it use an additional IRQ and consume some CPU resources or possibly introduce some conflict and increase the likelihood of dropouts in my already heavily-taxed DAW?

Thanks again!

[james]

I was testing it by hitting only one string and one note. I held the note without releasing and repeatedly picked on the string, making sure to hit only that string. Sometimes it would play an octave lower. This problem seems to manifest after several hours of playing, not when I have just turned on the computer and connected the i2M. Also there was one instance when I suddenly lost connection -- the Sonuus LED went out.

MIDI conversion is never 100% accurate, but we get quite close. But, if it's getting worse after several hours this does seem strange. The Sonuus LED going out can happen sometimes if there is a large power surge nearby the unit.

After it gets worse, if you disconnect then reconnect the i2M, does it improve again?

So installing the ASIO driver wouldn't help at all to improve the MIDI tracking? How does it work? Does the i2M have an internal A-D converter which converts the analog input to digital, which is then followed by a circuit that analyzes the digital audio stream and converts it to MIDI, and then the MIDI and digital audio are transmitted via USB to the computer?

The i2M does indeed have an internal A-D converter. The output from this is split in two: one part goes directly to USB Audio, and the other part gets passed to the MIDI conversion algorithms. The Audio and MIDI are then streamed (on different USB data streams) via USB to the computer.

The key thing is that the audio that you see via USB is exactly the same as is processed by the MIDI conversion algorithms, so you can look at the audio to check there is nothing strange going on. For example, if something in the pre-amp failed, you would see it in the audio and it would explain MIDI conversion problems.

So, the ASIO driver doesn't affect MIDI performance at all -- the ASIO driver is on the computer and by the time it gets there, the MIDI processing has already been done inside the i2M.

If I record the audio from the i2M, will I be using its A-D converter (if it has one) and not the excellent converter of my Mytek?

Yes, if you record audio from the i2M, it won't be using your Mytek.

If I install the i2M ASIO driver, will it use an additional IRQ and consume some CPU resources or possibly introduce some conflict and increase the likelihood of dropouts in my already heavily-taxed DAW?

If the i2M ASIO driver is installed by not being used by software, it will not use any resources. Actually ASIO technology is a service, not a true driver, so it doesn't do anything until it is loaded by an application.