In the I/O Setup, just double-click the name of the path that you want to rename, type in the new path name, and then hit Enter. If you want, you can rename the I/O paths to how you had them set before as long as everything is working OK. Do a test recording or import some audio and see if your issue persists. The session will now be created with the default input/output settings for your audio interface.Under 'I/O Settings' choose the 'Stereo Mix' option.Click on the '>' button next to 'Session Parameters'.From the Quick Start menu, choose 'Create Blank Session'.Double-check your input and output settings in the Mix window of Pro Tools to make sure that they're now set correctly and test your input/output again.The input and output paths for your audio interface should now be set to the default settings.Click on the Input tab and then the Default button again.Click on the Default button towards the bottom left corner. By default, you'll be on the Output tab.Make sure your audio interface is selected as the Playback Engine.If you are unable to get input into or hear output from Pro Tools the following troubleshoots may fix the problem. Click on the Apple menu in the upper left corner of your screen.Reset System Management Controller (SMC).Deleting Digidesign Databases and Preferences.Disable Sudden Motion Sensor (For laptops only.).For best possible performance, it is recommended that you do the following:

Pro Tools can be affected by system settings and other software and hardware drives installed on your computer. Snow Leopard Optimizations and Troubleshooting Mac Guide - Mac OS X 10.6 Snow Leopard Optimizations and Troubleshooting

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