Waves Primary Source Expander User Guide
A comprehensive guide to using the Waves Primary Source Expander (PSE) plugin.
Introduction
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The Waves Primary Source Expander (PSE) is a tool designed to reduce stage noise and increase gain before feedback without distorting the source's tonality. PSE is valuable for live shows and studio work. When mixing live material, PSE helps reduce extraneous noises while preserving natural ambience.
At its core, PSE is a precision expander, tailored for melodic sources like vocals, strings, woodwinds, brasses, and guitars. It functions like a fader that lowers a channel's level when the source falls below a set threshold. Both threshold and attenuation are user-defined, making it a simple yet effective tool with few controls that can often be "set and forget."
Basic Operation
The PSE is a very smooth expander. Its most important controls are Threshold, which sets a level threshold for your source (e.g., a vocal), and Range, which determines the amount of gain reduction applied when the source is below the threshold. Release Time is set according to the source material.
This guide uses the Primary Source Expander on a vocal track as an example, but it applies equally to speakers or instruments.
- Insert PSE on the desired channel.
- Raise the Threshold fader until the side chain input meter is solidly blue during sung phrases. Between phrases, the meter should drop to orange. Use the [+] and [-] Threshold buttons to fine-tune the threshold point.
- Set the Range to around -6 dB. This means that when the singer is not singing (between phrases), the level can be reduced by up to -6 dB.
- Initially, set Release to SLOW to avoid cutting off the ends of words.
- Observe if the level reduction is seamless. If the sound is smooth, you can slowly increase the Range up to -12 dB for maximum feedback and noise reduction, but do so gently for natural results.
- Experiment with the Release radio buttons to match the source signal. "Legato" sounds benefit from the SLOW mode, while "staccato" sounds work better with the FAST release time.
Side chain options can further improve gain reduction between phrases and reduce sensitivity to feedback.
Primary Source Expander Controls and Displays
The plugin interface features several key controls:
- WavesSystem Toolbar: Located at the top, used for saving/loading presets, comparing settings, undo/redo, and resizing.
- Release Time: Controls the release time of the expander, with options for SLOW, MEDIUM, and FAST.
- Threshold: Sets the level at which the PSE begins to lower the volume. The side chain input meter indicates the source audio level relative to the threshold (orange below, blue above).
- Range: Determines the amount of gain reduction when the input signal falls below the threshold. The Range meter shows the reduction in dB.
- Ducking On/Off & Delay: Controls the ducking feature and its associated delay.
- Side Chain Monitor & Source: Allows monitoring of the side chain source and selection between internal (INT) and external (EXT) sources.
- Ducking Gain: Adjusts the amount of gain reduction applied during ducking.
- Side Chain Filters (HPF/LPF/LINK): Filters (High-Pass Filter, Low-Pass Filter) can be applied to the side chain source. The LINK button synchronizes HPF and LPF adjustments.
Note: When the Side Chain is set to INT, Ducking Delay is not relevant and is deactivated.
Dynamics Section
Threshold
Determines the level at which PSE starts reducing volume. The side chain input meter is orange when the source audio level is below the Threshold value and blue when it's above. When the audio level is above the Threshold, the audio is unaffected. Use the [+] and [-] momentary toggles to fine-tune the Threshold setting by 1 dB per click. Range: -60 dB to 0 dB.
Range
Determines how much the level is reduced when the input signal drops below the Threshold. The Range meter is red and displays the amount of audio level reduction in dB. The reduction level never goes below the set Range control value. Use the [+] and [-] momentary toggles to fine-tune the Range position by 1 dB per click. Range: -60 dB to 0 dB.
Release
Three radio buttons are used to set the release time, chosen based on your source material:
- Slow: Approximately 500 milliseconds.
- Medium: Approximately 250 milliseconds.
- Fast: Approximately 100 milliseconds.
Ducking Section
Ducking provides gain reduction during periods of relative silence. Its behavior varies depending on Ducking/Side Chain settings.
Ducking On/Off
Turns the ducking section on and off. Range: ON and OFF.
Ducking Delay
Introduces a delay to align the side chain source with the PSE channel.
Delay Units
Sets the units used for Ducking Delay input and display. Changing the unit does not affect the delay amount, only its presentation. Range: Milliseconds, feet, meters.
Delay Value
Sets the value of the side chain delay. The selected value is shown in the middle of the panel. Range: 0 - 50 ms.
Ducking Gain
Sets the amount of ducking gain. Higher settings result in greater gain reduction. Range: -48 dB to +12 dB.
Side Chain Section
SC MON
Use the SC MON button to monitor the side chain source. Range: ON and OFF.
SC SOURCE
Sets the side chain source. Range: INTernal or EXTernal.
HPF/LPF/LINK (Side Chain)
Use HPF and LPF to filter the side chain source. These filters affect only the side chain source that triggers PSE, not your actual sound. The LINK button links HPF and LPF values, allowing them to move together.
Note: When the Side Chain is set to INT, Ducking Delay is not relevant and is deactivated.
Using PSE
The Primary Source Expander (PSE) plugin operates in four distinct modes, each tailored for different scenarios. This section explains the differences between these modes and when to use each for optimal results.
Mode 1 – Source INT, Ducking OFF
This is PSE's default mode, using an internal sidechain source (INT) with ducking off. PSE reduces gain whenever the input signal drops below the selected threshold, by the amount set by the Range control.
Problem: An electric guitar amplifier makes noise even when the guitar is not playing.
Solution: Insert PSE on the guitar channel to reduce noise when the guitar is not playing and the amp is idle.
Mode 2 – Source INT, Ducking ON
This mode improves internal sidechain behavior by enabling ducking. It's particularly useful when environmental noise is inconsistent, preventing PSE from reducing gain smoothly. In INT Side Chain mode, ducking adds DC (direct current) to the sidechain detector, effectively raising its noise floor and smoothing low-level detection.
Increasing ducking gain enhances PSE's stability when lowering gain between phrases, contributing to consistent gain reduction. Adjust ducking gain manually until sufficient reduction is achieved between phrases. Avoid excessive ducking gain, as it can truncate musical phrases. Use the Ducking On/Off toggle to assess results.
Problem: A vocal microphone picks up significant stage noise when idle or when the performer sings in front of PA speakers.
Solution: Insert PSE on the vocal channel, adjust Threshold and Range as desired, then gently add ducking gain for consistency.
Mode 3 – Source EXT, Ducking OFF
When the sidechain is set to an external source (EXT), PSE attenuates the channel's gain by the amount set by the Range control. However, PSE is triggered by the external source (a different channel). Attenuation occurs only when the external sidechain input level is below a set threshold. When the external sidechain input level rises above this threshold, PSE stops attenuating. The input meter behind the Threshold control reflects the EXT sidechain input level.
Problem: Mixing a choir with sensitive condenser microphones; need to attenuate idle mics to avoid stage noise leakage when the choir isn't singing.
Solution: Use a "trigger" mic (e.g., a powerful singer's lavaliere mic, not amplified in the PA). Route choir microphones to a group, insert PSE on this group, set it to EXT Side Chain, and select the "trigger" mic as the external sidechain input. When the trigger singer is silent, choir mics are attenuated; when they sing, attenuation stops.
Mode 4 – Source EXT, Ducking ON
This is a mixed mode. Like Mode 1, PSE attenuates gain when the input signal drops below the threshold, by the amount set by the Range control. Additionally, when a loud stage source prevents consistent attenuation, this mode uses a sidechain input to trigger added attenuation, aiding attenuation between phrases. The amount of added attenuation depends on the ducking gain setting; higher values yield greater reduction. Avoid excessive ducking gain, as it can truncate musical phrases. Use the Ducking On/Off toggle to assess results.
Problem: PSE is on a vocal channel, but snare drum bleed into the vocal mic prevents PSE from lowering vocal gain between sung phrases.
Solution: Route the snare channel to PSE's external sidechain input. Switch to EXT Source and turn Ducking on. Adjust delay settings so the direct sound and the bleed arrive simultaneously. Delay units can be ms, feet, or meters. If the snare is six feet away, set Delay Units to FEET and Ducking Delay to "6."
Presets and Settings
WaveSystem Toolbar
Use the toolbar at the top of the plugin to save and load presets, compare settings, undo/redo steps, and resize the plugin. For more information, click the icon in the upper-right corner of the window to open the WaveSystem Guide.
When routing multiple sources to the PSE sidechain input, set Ducking Delay according to the closest source. For example, if electric guitar and snare bleed into a vocal mic, route both instrument channels to PSE's Side Chain Input. If the guitar is closer, set Ducking Delay to the distance between the guitar amp and the vocal mic. If the snare is closer, set it to the distance between the snare and the vocal mic.
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