Tuesday, June 19, 2018

Mixing with SpecTrend™
Pink-Noise Weighted Metering

You may have read or seen something in the past year or so about using pink-noise as a reference for mixing.  The way it works is--- you listen to pink-noise while you solo each instrument or voice in your mix.  You then adjust the level of the part until it is just barely heard above the pink noise.  Once you have done this for each track, the mix should have an overall balance consistent with pink-noise.

The technique works because, as it happens, well balanced music follows the same frequency distribution as pink-noise.
  • Pink-Noise is random noise with level decreasing at -3db per octave as the frequency increases (also called 1/f noise).
In other words, well balanced music also decreases at -3db per octave as the frequency increases.  If you view the spectrum of high quality recordings you will see that they follow this -3db per octave pattern.

The problem with the pink-noise matching technique is that it is very tedious, requiring you to do each track, one-at-a-time.  It also requires a good source of pink-noise, which is surprisingly hard to find.  And, you must have good ears and/or a good listening environment to be able to hear it well---tedious and time consuming! So, it is easy to see why it is not a universally used technique, despite the fact that, theoretically, you should be able to achieve a balanced mix.

This is where SpecTrend™ comes in. What is new with SpecTrend™ is that the spectrum display is mathematically weighted to match a perfect pink-noise spectrum.  This means that the SpecTrend™ metering shows all 1/3 octave bars at the same level when the mix is balanced across all frequencies.

So, when using SpecTrend™, you just look to see that all the level bars are more-or-less equal, and you know the mix is balanced!  All the bars approximate a rectangle when the levels match, so it is visually easy to see that you have achieved your balanced mix.

And, of course, you are able to view the whole mix at once, without having to go through and solo each track.  And you never have to listen to pink-noise!  The metering is all done mathematically.

In addition, the 1/3 octave bars are color coded according to level, with green being the target range.  So achieving a frequency balanced mix becomes a matter of constructing a "green rectangle"!  How easy is that!

Frequency balancing the mix then, becomes just a matter of adjusting each track's level and/or EQ, until all the 1/3 octave bars are equal.  Done.

It is even a great tool for production and arranging.  Since the display allows to see each 1/3 octave band individually, it is easy to see when a particular frequency band is "overloaded", or maybe "empty".  So, you modify the arrangement, perhaps, raising a part an octave, to better balance the mix.  Or add another part in the "empty" frequency range to fill out the bands equally.

And, it should be mentioned that, although SpecTrend™ achieves its display mathematically, without introducing any noise, it does include a noise generator for testing and reference purposes.  The noise generator can produce pink-noise or white-noise.  There is an included level control.  And the output routing either sends the noise only to the meter, or to the output (speakers), or a mix of input and output.

It should be noted that in "Output" mode, the noise goes only to the output to be played, for example, over your speakers.  The input to the track is displayed on the meter.  You can then set up a microphone to feed the track and allow you to see the frequency response of your room and speakers.  So, in addition to mixing and arranging duties, SpecTrend™ can also be used to set up your mixing environment!

So, SpecTrend™ gives you a tool that allows you to do the pink-noise spectrum matching in an easy to use plugin (VST, VST3, AU, AAX, for Mac and PC).  It is no longer necessary to be born with "golden ears" to achieve that great mix. Check it out and see what it can do for your mixes!
  • Full Disclosure: Direct Approach is my company, and I am the creator of the SpecTrend plugin.