Fixing Phasing Issues
Phasing issues have long been an obstacle for a good sounding mix. They can occur with many instruments in the music production process and tend to sound unpleasant. To fix this problem, audio engineers have been applying various techniques in the past. Recently, some handy software plugins that remove this annoying phase issues got available, and I’ve come across a plugin particularly made to treat phase issues. Besides that, it possesses a lot more options like Track time shifter, Mid-side stereo widener, Stereo panner, Stereo balance meter, and Stereo correlation analyzer. In the next tutorial, I have chosen to apply this effect to a kick & bass in a previously made Psytrance project. Additionally, I will guide you through the PHA-979 interface, followed with a couple of audio examples.
As usual, we can start by adding PHA-979 by Voxengo to the bass channel in our SoundBridge project.
PHA-979 is a professional audio plug-in which allows you to apply an arbitrary phase shift to the sound material. The phase shift is a simultaneous shifting of all frequencies across the active frequency range of the signal by the given value in degrees. This is achieved by linear-phase design. Upon opening, we can see some main dial knobs.
At first, the parameters might be confusing, but they are not. The interface consists of 3 main sections, so let’s dive into the details.
The first section on the left is reserved for “Delay. The “Left” and “Right” knobs control the delay time (in milliseconds) independently applied to the left and right channels, respectively. The plug-in can apply negative time delay (shift the channels “back in time”) due to constant technical processing latency the delay module introduces in the first place. You can enable or disable it or type the desired values by clicking on a “calculator” tab in the bottom.
This set of controls allows you to perform phase alignment of mono or stereo audio material. Phase alignment is a second step after time alignment on the way to achieving a clear sound. The “Left” and “Right” knobs specify the phase shift value (in degrees) for the left and right audio channels, respectively. Phase shifting process of this plug-in does not skew the phase relationship within the signal being processed. For example, with this process, you can shift the phase of the signal twice. At first, by 90 degrees and then by 180+90 degrees (totaling 360 degrees), to get the original signal as a result. The “L 180” and “R 180” switches enable 180-degree phase inversion (flip) of the left and right channel, respectively. The “Corr” button opens the “Correlometer” pop-up window.
The “Side Mix” knob adjusts the amount of side channel signal present in the output signal (in percent). When the knob is at 100% (no mid-channel present) the resulting full side channel output will be 6 dB louder in comparison to 50% position to account for a usually quieter side channel signal.
The “Pan” knob controls output signal panning (in percent L-R). The plug-in uses “0 dB” pan law for stereo panning.
The “Out Gain” knob adjusts the overall output signal gain (in decibel).
The “Force Mono” switch enables processing of the left audio channel only. This switch is designed to be used on mono tracks (for example, during multi-microphone drum kit mixing) since in such cases this will save some CPU resources. When this switch is enabled, it dims the right channel knobs on the user interface making it clear that the plug-in is working on a mono source. Input right channel signal will be discarded completely when this mode is engaged.
The “L/R Swap” switch enables left and right channel swapping before the “Side Mix” and “Pan” adjustments are applied.
Finally, the “Mono Mix” switch enables the mixing of left and right channels to mono on output.
Setting the bassline to mono
Since Kick drum and Bassline in a variety of electronic music are set to mono, I have decided to make the bassline mono as well. Therefore before any further processing, I enabled the “Force Mono” option within the plugin. Let’s now hear a few audio examples with different changes in “Delay” and “Phase” sections. First, we will hear the audio example without any processing. I advise you to use high-quality headphones or a pair of studio monitors to notice the effect fully.
~Kick Drum & Bass Line – Unprocessed
~Kick Drum & Bass Line – PHA-979 process 1
`Kick Drum & Bass Line – PHA-979 process 2