I've just started using the i2M to play out, with a 2007 Macbook (2gHz Intel Core2Duo, 4gb RAM, Ableton Live), and every 5-15 minutes I get this weird, scratchy digital distortion that seems to build up, then dissipates again just as quickly. I've tried turning the volume down on the instruments (it happens on any, including a mic input), and even putting a preamp pedal with a volume control between the instrument and the i2M to enable me to lower the sound without affecting the tonality of the instrument, but to no avail. Even when not triggering the red clip indicator, this distortion still appears periodically, I'm hazarding a guess at between every 5-10 minutes.
Is there anything from the Mac itself that could be causing this? It only ever happens with the audio, never the MIDI signal. Is there something on the Mac that I could turn off to stop it from doing this?
Weird digital distortion.
Re: Weird digital distortion.
I think this might be resampling artifacts.
When using one device as an input (in this case the i2M) and another device as an output, the computer needs to dynamically match the sample rates of both devices. It does this by resampling and interpolating the "slave" device so it matches the "master" device's clock.
Generally, the Mac handles this pretty well, but I have sometimes seen it go wrong and do things as you describe.
In Ableton Live, do you need to create an aggregate device to get the i2M working with another output, or can you directly select the i2M as the input and another device as the output? With an aggregate device you can select which one is the master (the clock), and we've found it's usually best to use the i2M as the master. See if you can set which is the clock master.
We've also found that rebooting can help. Have you tried that?
When using one device as an input (in this case the i2M) and another device as an output, the computer needs to dynamically match the sample rates of both devices. It does this by resampling and interpolating the "slave" device so it matches the "master" device's clock.
Generally, the Mac handles this pretty well, but I have sometimes seen it go wrong and do things as you describe.
In Ableton Live, do you need to create an aggregate device to get the i2M working with another output, or can you directly select the i2M as the input and another device as the output? With an aggregate device you can select which one is the master (the clock), and we've found it's usually best to use the i2M as the master. See if you can set which is the clock master.
We've also found that rebooting can help. Have you tried that?
Re: Weird digital distortion.
Thanks for the reply, James. I think that may have solved the problem, I've had a few runs at it using the i2m as the master clock, and so far so good. 