A very common cause of confusion for a new user of Pro Tools is not knowing what to do when you hit play only to be greeted by silence. Here are some things to know.
1 - Check hardware first!
Because there are so many things which can go wrong in software it is tempting to assume that the problem must be in software - Not necessarily!
2 - Is the volume up?
Don’t crank it up and leave it there if it is not the problem, turn it back down or you might get a big shock when you do find what is wrong.
3 - Are your peripherals connected and powered?
A buss powered audio interface should have status lights on it. Are they on? A favourite mistake which I have to admit I have made more than once in a computer lab style classroom is to adjust the headphone level of the interface being used by the person next to me.
4 - Look at the software settings
Once you have eliminated obvious hardware issues (are your headphones plugged in? I know it sounds obvious but I have watched people busily check IO settings with their headphones disconnected more than once) it is time to look at software.
5 - System Preferences vs Playback Engine
Many new users do not appreciate that there are audio settings for the whole OS (i.e. computer-wide) and audio settings for the specific application you are using (i.e. Pro Tools). Changing system settings will not affect Pro Tools, to do that you need to access the Pro Tools playback engine.
The Pro Tools Playback Engine is accessed from the Setup menu and it is here you can select which audio interface you wish to use with Pro Tools. Because there are sound settings for the operating system (i.e. the whole computer - web browser, iTunes etc.) and for just for Pro Tools, it is possible to have sound hardware which is used by the rest of the system and different hardware which is just used by Pro Tools. The available Pro Tools playback engines are accessible from here. People trying to fix a playback engine issue by changing the System Preferences > Sound settings (PC - Control Panel > Hardware and Sound) is one of the most common causes of confusion I have come across. If you are using on board sound hardware on a Mac you will be using Core Audio. If you are using Windows you will need to use an ASIO driver for your on board audio on your PC. ASIO4All is a generic ASIO diver for windows machines. Neil posted a video on setting this up. On a Mac Pro Tools sees the core audio input and output as separate devices and Avid created an aggregate device combining them both called Pro Tools Aggregate IO. If you want to use the on board IO this is the option you need.
6 - Outputs inactive/unavailable
To hear a track it has to routed to an available output. It is unusual for this to present many problems unless a session has been created on another system. If is has then Pro Tools should be able to “map” the outputs imported with the session onto the appropriate output on the system the session is being opened on. If this does not work the invalid output will show up as italicised. The most straightforward way to fix this is to hold down option/alt and click on the output selector for one of the tracks which is assigned to the inactive main output and select the appropriate available output. Using the option/alt key will apply this change to all tracks in the session apart from masters. This will of course disrupt any submixing or bussing in the session. There are more elegant ways of fixing this problem but for simple session this method is adequate.
7 - Mix Control/Software
A final thing to check is whether any features designed to provide low latency monitoring while tracking are the problem. This only affects users with external audio interfaces but a common cause of confusion is the role of the mix control found on many USB interfaces. Use of these is beyond the scope of this article but if you cannot hear playback from Pro Tools make sure the mix control is not turned fully towards “input”. Some interfaces use some kind of mixer software external to Pro Tools to achieve the same thing. If your interface uses proprietary mixer software check the settings.