Dynamic equalizer is essentially a type of a conventional parametric equalizer. It is “dynamic” because the otherwise static gain of the filter is replaced by a dynamic control loop. Parameters such as frequency and quality (Q) remain the same. Depending on the design of the control loop, a dynamic EQ can have level-dependent parameters (over/under, threshold, and range) as well as temporal parameters such as attack, release and hold.
How does a dynamic EQ work?
A dynamic EQ works by making each filter`s gain control act in the same way as the gain change element. Depending on the model, there may be the option for it to mimic a compressor, an expander, or even a threshold independent transient enhancer. For each bend, you, therefore, need to decide on the filter type, frequency, and bandwidth. Then, you need to set up the band`s processing type and control it. If that sounds like a lot of work, you are not wrong. However, the upside of that is once you`ve got the hand of dynamic eq it can bail you out of various situations. This is by virtue of the fact that it can operate on precise frequency regions-or even single frequencies in some cases.
Why is traditional equalization not enough?
So the reason why traditional equalization alone is sometimes not enough comes down to this: One size does not fit all. By applying ‘regular’ EQ during mastering, and boosting some upper midrange (let’s say, around 3.5 kHz) will add bite to the guitar but will also make the vocal shrill whenever it strays into that area. Apply some low-frequency shelving at 60 Hz, and it will reduce the boom of the kick drum. It will also affect the fundamental of the bass when low notes are played. Applying EQ to individual instruments during recording or mixing does not solve the problem, either. A good setting for a vocalist singing softly rarely works when they begin attacking the chorus at a louder volume. Rolling off high frequencies to reduce the harshness of cymbal crashes will dull their sound even when they are tapped gently.
The common cases where dynamic EQ is most helpful:
1. With dynamic EQ you can rein in the shrillness in a singer’s voice when he or she begins belting out the chorus. But still retaining vital presence during the quieter verses.
2. Let’s say a hi-hat is too bright in a mix, but you’re happy with the snare sound. If you try and compress (or apply traditional equalization to) the hats, you’ll end up also dulling the snare sound. With a dynamic equalizer, you can use the snare hits as a sidechain input to the high-hat track. With this, you only roll off top end whenever the snare isn’t being hit. You can even EQ the transient of a sound one way, and the sustain portion a different way. You scoop out the “boxiness” of a sound without affecting its attack at all.
3. You can tame harsh cymbal crashes when the drummer starts getting carried away, but leave the cymbals untouched when the drummer is playing with a bit more restraint.
Additional resources & source texts
https://books.google.rs/books?id=4WlM5vpO5QsC&dq=dynamic%20equalizer&source=gbs_navlinks_s
