Hiss. The bane of the recording enthusiast’s life. You’d think that with all the digital recording gear at our disposal nowadays, hiss would be a thing of the past, yet even with tape a distant memory for most of us, there are still many things that can cause unwanted noise when recording with a Mac and GarageBand. Low recording levels, bad gain structure, dodgy cables and overly enthusiastic use of software amp simulators are only some of the culprits. But, regardless of the source of the hiss, once it’s on your recording, what can you do about it?
Using a guitar part sourced from an old cassette tape from 1984, we’ll take a look at some of the tools that the latest version of GarageBand provides to clean up your hissy fits. You can download our files from here.
Step-by-step: Reduce hiss on recorded material
1 Create project
Open a new, empty GarageBand project and create a new Audio track by clicking on the microphone icon, followed by the Create button in the bottom-right corner.
2 Drag and drop
Drag the audio file ‘Hissy Guitar 1.aif’ (found in the Tutorial Files section of this month’s iCreate disc) from the Finder onto the new track. Drop it at position 1 1 1 1.
3 Hit play
Click the toolbar button to disable the metronome, then play the audio. It was sourced from an old cassette, resulting in a substantial amount of hiss.
4 Choose preset
If not already open, click the button in the left of the toolbar to open the Library. From the preset list that appears, choose Legacy>GarageBand>
5 Take control
Click the button in the toolbar to reveal the Smart Controls panel. These are the controls for the hidden High Pass Filter and Speech Enhancer plug-ins.
6 Reduce noise
In the Speech Enhancer section, turn the Denoise control all the way up. This deploys the maximum noise reduction, suppressing the hiss while preserving most of the original tone.
7 Add Audio Units
Click the ‘i’ button in the Smart Controls pane, then click in the Audio Units tab and select Apple>AUParametricEQ from the menu. Press Keep when asked.
8 Seek it out
Push the control point up to the top of the window (watch the volume on your ’phones!) and sweep it around until you find the main centre frequency of the remaining hiss.
9 You’re hisstory
When you hit the right frequency, pull the control point down to lower the volume of that frequency. Our settings here are: Freq 11216Hz, Gain -20.0dB, Q 10.0.
Step-by-step: Reducing hiss
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