Introduction to MIDI and Computer Music: Clipping
Clipping is a technical term that refers to something you’ll want to avoid: amplitude levels that are too high for the digital audio system to encode. Such high levels often cause a nasty sounding digital distortion. Unfortunately, it’s easy for clipping to happen in Reason. Any project that has several tracks playing at once might have it. Fortunately, it’s also simple to control clipping within Reason. This webpage tells you how.
To avoid clipping in Reason, you first need to know two things: where clipping can occur, and how to watch and listen for clipping. This watching and listening is called monitoring. Reason has several different meters you can use to monitor the audio signal. It’s also important to know how to interpret what the meters show.
There is only one place where clipping can happen in Reason: the Hardware Interface. This is where audio enters Reason (if you are recording audio) or leaves Reason (if you are listening to your sequence play back). It is always present at the top of your rack.
Because clipping can occur only at the Hardware Interface, you don’t need to worry if the meters on mixer input channels, individual devices, or effects “go into the red.” That is okay, and doesn’t indicate clipping.
Look at the lower panel of the Hardware Interface, at the channel meters. There are three main sections: the Sampling Input (orange label), the Audio Input (gray label), and the Audio Output (blue label). Since we aren’t recording into Reason, just playing back, it’s the Audio Output level that we need to monitor.
DO THIS: Click the button under Audio Output channels 1 and 2 so that it turns red, as shown in the illustration above. This means you will monitor those channels. (Now flip the rack around and look at the back. Notice that the L and R Master Outs in the Master Section are patched to the Audio Output channels 1 and 2. These connections are made automatically when you open a Reason song file. Because you selected Audio Output channels 1 and 2, you are now monitoring your entire mix. Flip the rack back around to view the front.)
Notice that, when you select Audio Output channels 1 and 2, the Big Meter opens just below the Hardware Interface. This is Reason’s largest and most detailed meter. The signal level for the left audio channel (L) is shown above that for the right audio channel (R). Note the word CLIP just to the right of the L and R. If the red lights above and below the word CLIP turn on, as in the picture below, your sequence has clipping. These clip lights will stay lit until you press the RESET button.
Note that it’s okay for the meters to show red. That doesn’t mean the sequence is clipping. It’s only when the clip lights turn on that clipping is present.
Reason has three other meters you can use to monitor clipping:
Note that if you wish to use other MClass devices on the Master Section (for example, the MClass Equalizer or Compressor), the Maximizer should be the last device in the signal chain.