Gain Staging – the importance of volume in digital recording and mixing
If you have worked with recording and mixing in the analog realm (on tape) or using a 16 bit digital recording device you may have heard and lived by the rule ”record as loud as possible without clipping”. However, in a 24 bit digital environement the signal to noise ratio is improved to such an extend that you do not need to record that hot a signal.
On top of this most effect plugins are calibrated to function at their best with signals that are around -12 to -18 dB. If the signal you have recorded is higher than this it might cause distortion or unwanted artifacts when you run it through an effect plugin. To avoid this you should pay attention to proper gain staging: aim for a recorded signal between -12 and -18 dB.
If you have already recorded with a signal hotter than this you should turn it down. Most DAWs give you an opportunity to do that (look for a pre-gain knob) but should your DAW not have such a feature you can use the ”Free G plugin” by Sonalksis. Place it as the first plugin on the relevant channel(s) and turn the pre-gain volume down to the desired level. And yes, as the names says, “Free G” is a free VST plugin.
An easy way to measure the incoming or recorded volume level is to use a VU meter. If you are on a Windows operating system you can use the Sleepy Time DSP ”Mono Channel” and ”Stereo Channel”. Set the calibration to -18 dB. Your signal should now hit the VU meter around the 0 dB point when it is at its loudest. If you are on a Mac check out the Klanghelm ”VUMT” VU meter. It is very affordable and works in the same way.
By sticking to these basic rules for gain staging you avoid distorting your audio in unintended ways.
The Sleepy Time Mono Channel VST is a free VU meter plugin for Windows that can be used to set a correct gain staging.
The Klanghelm VUMT VST plugin is a very affordable VU meter for Windows and Mac that comes in handy when you set your gain staging.