Compressors are by far one of the most challenging mixing processors to set correctly. When we lower a compressor threshold we trigger compression which in turn dips the output volume. Commonly, this is what compressors do - the dynamic range of audio is squeezed so that we end up with nice and consistent dynamics in audio material, however, when a compressor threshold is lowered to tame peaky audio our ears and subconscious often make decisions well before we've had a chance to properly listen and judge the compression results. The lower volume caused by a compressor can often trick our ears into thinking we've got our compressor settings correct when in fact all we have done is squash the life out of a track. Inexperienced mixers struggle to hear the characteristics of compression when dialing in values - "is this compression setting good or bad?? Who knows! - my ears are already playing tricks on me as there is a level difference."
The only reliable way to hear the result of compression (after the fact of setting the controls) is to raise the output of the compressor (level match) so that we can A/B (before and after) compare the unprocessed audio and compression. This is the process experienced mixers use to ensure compression is set tastefully.
With hardware compressors, engineers use both their hands to physically set compression values.
Let's use my hardware Tegeler Audio Creme Bus Compressor as an example - One hand lowers the Threshold to trigger the compression while the other hand balances (turns up) the Output. In mouse and keyboard operated DAW workflows, users can only set a single dial at a time, this is frustrating, to say the least. When working with hardware compressors the two hand approach is instinctive, making compression very easy to set.
Limiter plug-ins also mislead the ear when dialing in values. Often, when a limiter threshold is lowered the output shoots up making the audio sound much louder. Our ears are very sensitive to this volume difference - inexperienced mixers believe louder is better - we know that's not the case.
Some limiters include an auto gain feature. Slates FG-X mastering limiter plug-in has a Constant Gain button that ensures the Output volume of the limiter stays constant when dialing through the limiting range. This feature makes it incredibly easy to find the limiter sweet spot every time. Features like this remove the guesswork from adjusting dynamics.
Some compressors and EQ plug-ins include Auto Gain features as well such as FabFilter Pro-C2 and FabFilter Pro-Q2 plug-ins. Auto Gain in an EQ I hear you say? Think about it... If you boost a wide band 10 dB you've changed the output level running the risk of your ears being misled in a similar way that happens when working with compressor and limiter plug-ins. Plug-ins that maintain a constant output level regardless of control value changes keep our ears focused on the job at hand.
Plug-ins That Feature Auto Gain
- Blue Cat's Dynamics (Make-Up Gain Compensate)
- Compressor - FabFilter Pro-C2 (Auto Gain)
- Compressor - Softube Console 1 (Compression module)
- Compressor - SSL X-Valvecomp (Auto Gain)
- EQ - FabFilter Pro- EQ2
- EQ - Redline Equalizer
- Limiter - Slate FG-X (Constant Gain)
- Limiter - FabFilter Pro-L (Hold keyboard Shift while increasing gain)
- Mastering - iZotope Ozone 7 (Ear Icon)
- Multiband - Waves LinMB (Auto Gain)
- Tape & Channel Emuations - McDSP AC101 & AC202 (Auto)
If we have missed any plug-ins that feature Auto Gain please share in the comments below
Auto Gain As A Standard EQ & Dynamics Plug-in Feature
I think it's time for EQ and Dynamics plug-in developers to include Auto Gain in their products as a standard feature. I consider Auto Gain in EQ and Dynamic plug-ins to be very important as these features remove the chance of my ears being misled in the mix stage. Dynamics are easy to get wrong, even for the experienced. Auto Gain also provides me with an extra...gain (pun intended) - It gives me the "right hand on the hardware output dial" feeling that is lost in mouse operated DAW workflows.
Do you think the Auto Gain compensation feature should be standard on EQ and Dynamics plug-ins?