Q: How should I set the threshold of my equalizer?
Here is the question exactly as it came in to us at Audio Masterclass Towers...
"thanks alot for your news letter, butÂ iwant to know the meaning of treshold in equalizer and its aplications"
Reading between these particular lines, our normal answer would be that compressors, limiters, expanders and noise gates have threshold controls, equalizers do not.
There, that's done then.
What if you could have an equalizer that would operate differently according to the signal level? Then indeed you might want to be able to set a threshold, so that the EQ only kicked in above or below a certain level.
Well indeed there are such things. We put the phrase 'dynamic equalizer' into a well-known search engine expecting to get a list of dynamic EQ plug-ins. Instead, at the top of the list we found this...
"The Audyssey Dynamic EQ - Preserving bass and clarity at low volumes"
Yes, it's home hi-fi technology, and you can find it built into a wide range of equipment from a variety of manufacturers.
And although it is hi-fi technology, it is something that you really should be aware of in the studio as people could be listening to your mixes through it!
The idea is that the human ear's frequency response changes with the loudness of the sound it hears. At high levels, the ear's response is fairly even over the frequency range. Hardly ruler-flat, but flattish.
But at low listening levels the ear's response to low and high frequencies drops dramatically.
So anyone foolish enough to listen to music quietly isn't going to get the full frequency range experience that the producer and artist intended.
But a solution for this has been around for decades - the loudness button.
Many hi-fi amplifiers have a loudness button, but most users don't have a clue what it is supposed to do.
The idea is that if you are listening at a low level, then you can press the loudness button for a boost in the low and high frequencies.
The problem with this always has been that people presume that it's an 'extra loudness' button and use it pretty much at random. Oh well.
But Audyssey Dynamic EQ is rather more sophisticated. It senses the level of the signal continuously and applies boost when necessary. And what's more, it follows the response of the ear closely using an updated version of the well-known Fletcher-Munson curves.
So yes indeed there is a threshold involved.
And what does this have to do with studio producers?
Well it means that your listeners are buggering about with your mix. You made a great mix in the studio, you had a great master made. And now the people who have paid good money for the brilliance of your work are changing it to suit their own tastes.
Well that just shouldn't be allowed.
But seriously, if this is what people are doing at home, then if it proves popular we can expect them to be doing more of it in the future. It's another thing for the producer, and the mastering engineering in particular, to be aware of.
So soon we may recommend not only auditioning your mix on main monitors, nearfields, headphones, iPod earbuds and in the car, you should audition it on a Dynamic EQ playback system too!