Hi. I am Darran Kelinske from Austin, TX in the USA. This lesson is for Week 4 of Introduction To Music Production at Coursera.org. This week I will be teaching you about the Gate effect that is available in Ableton Live. I will give a brief overview of the Gate effect and discuss the some of the parameters and visualizations the Gate effect provides.
In this lesson we will be using our audio recording from the past few week’s assignments (found below).
What is a Gate Effect?
According to the Ableton Live manual:
“The Gate effect passes only signals whose level exceeds a user-specified threshold. A gate can eliminate low-level noise that occurs between sounds (e.g., hiss or hum), or shape a sound by turning up the threshold so that it cuts off reverb or delay tails or truncates an instrument’s natural decay.”
In other words, a Gate effect is a device that allows us to only allow sound through that is above a certain threshold level. In addition, to setting the threshold level that allows sound to pass through, Gates typically have other parameters which include ratio/floor, return, attack, hold, and release.
A screenshot of the Ableton Live Gate effect is pictured below.
The Threshold parameter sets the dB level at which the Gate will allow sound to pass through. This setting can be modified in Ableton Live by dragging the horizontal line displayed on the Gate effect, modifying the knob underneath the Treshold setting, or using a knob on a connected controller like an APC40.
Setting the Threshold value to a level that only lets the loudest sounds through creates a pulsing kind of effect on the audio track.
This setting is explained well in the Ableton Live manual:
“Return (also known as “hysteresis”) sets the difference between the level that opens the gate and the level that closes it. Higher hysteresis values reduce “chatter” caused by the gate rapidly opening and closing when the input signal is near the threshold level. The Return value is represented in the display as an additional horizontal orange line.”
In the screenshot below we can see the range that is created when setting a return level. As mentioned earlier, this range is depicted by a second horizontal bar that is displayed on the Gate effect. A further description of the Threshold and Return/hysteresis settings can be found on Wikipedia here.
Setting a Return level removes some of the pulsating created by using the Gate in the previous recording by allowing the Gate to remain open as the sound level level is decreasing.
From the Ableton live manual:
“The Attack time determines how long it takes for the gate to switch from closed to open when a signal goes from below to above the threshold. Very short attack times can produce sharp clicking sounds, while long times soften the sound’s attack.”
When setting the Attack time to 0.02 ms, the Gate produces a clicking sound.
From the Ableton Live manual:
“When the signal goes from above to below the threshold, the Hold time kicks in.”
The Hold time is the time the Gate will remain open once the signal falls bellow the the threshold.
From the Ableton Live manual:
“After the hold time expires, the gate closes over a period of time set by the Release parameter.”
In other words, the Release time is the amount of time that will be spent closing the gate. As with Hold, please be aware that setting long Release times may result in the Gate remaining open despite a drop in signal.
This graph on Wikipedia is a great visualization of how the various Gate parameters effect signal flow.
From the Ableton Live Manual:
“The Floor knob sets the amount of attenuation that will be applied when the gate is closed. If set to -inf dB, a closed gate will mute the input signal. A setting of 0.00 dB means that even if the gate is closed, there is no effect on the signal. Settings in between these two extremes attenuate the input to a greater or lesser degree when the gate is closed.”
A Ratio setting is not included in the Ableton Live Gate effect, but a Ratio parameter allows you to specify the ratio at which sound will be attenuated. Ratio’s are specified as a ratio of input signal to output signal. I found a good description of Ratio settings related to Gates from DoctorProAudio.com.
“The attenuation ratio works in an equivalent way to that of the compressor, defining the amount of a attenuation (compression) that is applied to the signal. These ratios are expressed in dB, so that, for example, 1:6, means a signal that is 1 dB below the threshold will get reduced to 6 dB below it, while a signal 3 dB below the threshold will get reduced to 18 dB below it. Likewise, a 1:3 (one to three) means a signal 1 dB below the threshold will be attenuated 2 dB (as the level will go from -1 dB to -3 dB; we use a negative sign as these levels are below the threshold, which is the 0 dB reference in this case). With a ratio of 1:10 and higher, the expander is considered to work as a pure noise gate, though an ideal gate would have a theoretical ratio of 1:infinity (any level below the threshold would be totally muted).”
The Gate effect in Ableton Live gives us a few visual indicators to help us better understand the impact the Gate is having on our signal. The image below highlights where the threshold, return, output signal, and gain reduction meter are located on the Ableton Live Gate effect.
In this post, we reviewed the Gate effect that is available in Ableton Live and how some of the parameters in the Gate effect impact sound. While I have begun to understand how the various settings function, it will take much longer to understand how to use them musically. If there are any inaccuracies or if there is any feedback you have to provide, please contact me through Coursera or social media. Thank you for reading.
Lastly, the Ableton Live Project used for this post can be found UsingAbletonGatePlugin Project.