Signal Processing in Adobe Audition CC

This chapter is from the book

Adobe Audition CC Classroom in a Book

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This chapter is from the book

This chapter is from the book 

Adobe Audition CC Classroom in a Book

Learn More Buy

Special effects

Two individual effects—Distortion and Vocal Enhancer—are discussed in this section as well as two “multieffects” for Guitar and Mastering that include several compatible effects designed to work together.

The Special Effects section also allows you to access the TC Electronic ITU Loudness Radar meter, which does not alter sound but is more of a diagnostic or measurement tool. It’s discussed in Chapter 6, “Mastering.”

Distortion

Distortion occurs by clipping a signal’s peaks, which creates harmonics. Audition’s distortion can create different amounts of clipping for positive and negative peaks to produce asymmetrical distortion (which can produce a more “jagged” sound) or link the settings for both peaks to produce symmetrical distortion, which tends to sound somewhat smoother.

1. Choose File > Open, navigate to the Lesson04 folder, and open the file Bass110.wav. Play the file to hear what it sounds like.
2. Click an effect insert’s right arrow, and choose Special > Distortion.
3. Load various presets to get a sense of the sounds this effect can create, and then return to the Default preset. This preset has no distortion, because the curves represent a linear relationship between input and output with no clipping.
4. Now you’ll create some light distortion to give the bass some “crunch.” Click the Link button (under the cursor in the screen shot) between the two graphs so that adjusting one curve affects the other. (Note that clicking one of the two arrows below the Link button transfers one curve’s settings to the other.)
   

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5. With the bass file playing, click the white square in the upper-right corner of a graph’s curve. Drag it down to -15 or so, and you’ll hear the sound become more distorted as you lower the level where the signal clips. Because more clipping leads to lower levels, you’ll need to increase the Effects Rack’s Output control to compensate.
6. Click at the intersection of the two -30 levels on the X and Y axes to create a new node on the curve; you’ll hear more distortion. Boosting lower levels causes them to distort more readily.
7. Drag this new node up to increase the volume of low-level signals, thus creating more distortion. Dragging the node to the left also increases distortion by allowing lower levels to distort.
8. To remove a node, right-click (Control-click) on it. Continue adding and moving nodes to hear how this affects the sound. When there are multiple nodes, you can smooth the curve that incorporates them by increasing the Curve Smoothing parameter value.
9. Click a graph’s reset button (the spiral arrow). If the graphs are still linked, you’ll reset them both simultaneously; otherwise, you’d need to reset them individually. With the graphs unlinked, bring the upper-right square for one of the graphs down to -20dB. This adds crunch but also preserves the “fullness” of the bass by leaving one set of peaks alone.
10. Increase Time Smoothing, and the distortion becomes smoother and less harsh. The reason is that the Time Smoothing parameter changes the distortion’s reaction time to level changes, particularly at lower frequencies. Choose a value of 30%, and then bypass/enable the distortion to compare the distorted and undistorted sound. Note how the smoothing creates a softer kind of distortion quality that gives the bass a bit of “snarl” but still sounds musical. Processing a bass with a hint of distortion can help it stand out more in a mix.

Vocal Enhancer

The Vocal Enhancer effect is one of Audition’s easiest effects to use because it has only three options.

1. Choose File > Open, navigate to the Lesson04 folder, and open the file NarrationNeedsHelp.wav. Play the file by pressing the spacebar.
2. Click an effect insert’s right arrow, and choose Special > Vocal Enhancer.
3. Click Male to reduce the low end somewhat to minimize p-popping and booming; note that it also helps even out the level variations a bit.
4. Load the file Drum+Bass+Arp110.wav, and insert the Vocal Enhancer in the Effects Rack. Select the Vocal Enhancer’s Music option.
5. Bypass the Vocal Enhancer. You’ll hear that the music is brighter, which could potentially interfere with vocal intelligibility. Enabling the Vocal Enhancer’s Music option creates more “space” for voice-over.
6. With the same file playing, click the Male and Female options. You’ll hear how this affects music, which makes the changes in frequency response more obvious.

Guitar Suite

The Guitar Suite is a “channel strip” that emulates a guitar signal processing chain. It includes four main processors; each of which you can bypass or enable individually:

• Compressor. Because guitar is a percussive instrument, many guitar players use compression to even out the dynamic range and produce more sustain.
• Filter. This shapes the guitar’s tone.
• Distortion. This is a “condensed” version of the Distortion processor and offers three popular distortion types.
• Amplifier. A large part of a guitar’s sound is the amplifier through which it plays: The number of speakers and the size of each, as well as the cabinet, have a major effect on the sound. Fifteen types are available, including a cabinet for bass guitar.

Now, let’s walk through working with the Guitar Suite.

1. Choose File > Open, navigate to the Lesson04 folder, and open the file Guitar.wav. Play the file.
2. Click an effect insert’s right arrow, and choose Special > Guitar Suite.
3. Load the preset Big and Dumb, which makes a great start for a classic rock guitar sound.
4. Vary the Compressor Amount slider. The sound will be more percussive to the left and more sustained (with a slight volume drop) to the right. Set the Amount to 70 before proceeding.
5. Vary the Distortion Amount slider. The sound is “cleaner” to the left and “dirtier” to the right. Try the three different distortion types from the Distortion Type drop-down menu, and vary the Amount slider. Garage Fuzz is more punk, Smooth Overdrive more rock, and Straight Fuzz emulates the sound of a distortion effect box rather than an amp. Return to Smooth Overdrive, and set the slider to 90.
6. The sound seems a little harsh, but you can make it smoother by deselecting the Filter bypass check box.

7. Move the Freq slider to around 1500Hz with Resonance at 0. This removes some of the “edge.” Note how increasing Resonance makes the sound “sharper.” Leave Resonance at 0 for now.

   TIP

   Many guitar sounds use distortion. However, you want to avoid unintentional distortion caused by overloading within Audition and use only the intentional distortion created by the Guitar Suite processor. Guitar processors can cause wide level swings, so pay close attention to the Effects Rack panel’s Input and Output controls to make sure they don’t go into the red zone.

8. To hear how different amplifiers affect the sound, choose various options from the Amplifier Box drop-down menu—Classic British Stack, Classic Warm, 1960s American, 1970s Hard Rock, and Deep 4x12 are some of the most realistic emulations. Also, note that there are six non-amp and special FX sounds. Bypassing the Amplifier emphasizes just how much speakers and cabinets influence the tone.
9. Load the Big and Dumb preset to return to its original sound, but choose Classic British Stack for the Amplifier Box parameter. Deselect the Filter bypass check box.
10. The Filter precedes the Distortion section. Therefore, reducing signal levels due to filtering will result in less distortion. Often, this is the sound you want, but if you feel the overall level is too low, move the Distortion Amount slider to the right to compensate.
11. With Retro selected as the Filter, choose Bandpass for the Type (this is like a Parametric EQ stage without the boost/cut control). For a big, metal sound, set Freq to around 435Hz and Resonance to 20 to produce a little response peak at that frequency.
12. Feel free to experiment with the Lowpass and Highpass filter, but if you’re impatient to discover some other filter types, proceed to the next step. You’ve already worked with Lowpass and Highpass filters in previous sections on equalizers (Lowpass reduces highs; Highpass reduces lows); Resonance is equivalent to the Q control you used with some of the equalizers.
13. Choose Rez as the Filter and Bandpass as the Type (the other responses work too, but these produce the most obvious effect), and set Resonance to 0. Vary the Freq slider, and you’ll hear a resonant effect like a wah pedal. Turn up Resonance if you really want to go overboard.
14. Change the Freq slider position; note that this doesn’t change the TalkBox filter frequency per se but acts more like a “window” that sweeps across the filter frequency, making it more or less prominent. Each of the remaining five filters has a fixed frequency that corresponds roughly to the mouth’s filtering effect when forming various vowels.
15. Load the TalkBox U filter and select Bandpass for Type. With Resonance at 0, move the Freq slider across its range. The peak level will be around 1kHz; moving the Freq slider to either side reduces the level somewhat and also changes the timbre.
16. Choose File > Open, navigate to the Lesson04 folder, and open the file Drums110.wav. You’ll learn that the Guitar Suite is also suitable for other instruments, particularly drums.
17. Click an effect insert’s right arrow, and choose Special > Guitar Suite. Load the Big And Dumb preset.
18. Enable the Filter, and move the Freq slider to around 3000Hz. Set Resonance to 20%.
19. Although you’ll hear a good “trash” drum sound, you can tame it by moving the Mix Amount slider to the left (try 30%–40%). This adds the dry drum sound in with the “trash” sound so that the overall sound is more defined.

Mastering

Mastering is another effects “suite.” Note that Adobe Audition is an extremely capable mastering program, so including a Mastering suite may seem redundant. However, think of the Mastering effect as a quick way to master material that doesn’t require you to create an à la carte set of mastering processors within Audition.

The suite includes the following effects:

• Equalizer. Includes a low shelf, high shelf, and parametric (peak/notch) stage. Its parameters work similarly to the same parameters in the Parametric Equalizer effect. The Equalizer also includes a real-time graph in the background that shows the current frequency response spectrum. This helps with making EQ adjustments; for example, if you see a huge bass “bump” in the low end, the bass probably needs to be reduced.
• Reverb. Adds ambience if needed.
• Exciter. Creates high-frequency “sparkle” that’s unlike conventional treble-boosting EQ.
• Widener. Allows for widening or narrowing the stereo image.
• Loudness Maximizer. Is a dynamics processor that increases the average level for a louder sound without exceeding the available headroom.
• Output Gain. Can be adjusted to control the effect output and therefore compensate for any level changes due to adding various processes.

Now, let’s walk through working with the Mastering suite.

1. Choose File > Open, navigate to the Lesson04 folder, and open the file DeepTechHouse.wav. Play the file. Note that there are two problems: The bass “booms” a bit too much, and the high end lacks definition.
2. Click an effect insert’s right arrow, and then choose Special > Mastering.
3. Load the preset Subtle Clarity. Toggle the power button to enable/bypass the preset’s effect; note how this indeed produces more clarity.
4. You’ll now fix the bass. Select Low Shelf Enable; a small X appears toward the left, which you click on and drag to change the shelf characteristics. Resume playback.
5. Drag the Low Shelf marker right to around 240Hz. Then drag down to about -2.5dB. Enable/bypass the Mastering effect, and you’ll hear that when Mastering is enabled, the low end is tighter and the high end is more defined.
6. The Reverb parameter is set to 20% in the preset; move it left to 0%, and the sound will be a little “dryer.” A value of 10% seems to work well for this tune. Note that the Mastering reverb effect is not intended to provide big hall effects, but instead adds ambience when used subtly.
7. Drag the Exciter’s slider to the right, and the sound will become way too bright—a little bit of the Exciter effect goes a long way. (Most of the preset’s additional “clarity” is due to the slight, upper-midrange boost around 2033Hz working in conjunction with the Exciter, which affects the highest frequencies.) Because the song is already fairly bright, disable the Exciter effect by dragging its slider all the way to the left. (Note that the sonic difference among the three characters of Retro, Tape, and Tube becomes most noticeable with dull material and high Exciter amounts.)

8. Adjust the Widener to taste; end on a setting around 60.

   TIP

   It might seem logical to set the Widener for the widest possible stereo image to create a more dramatic sound. However, emphasizing the extreme left and right areas of the stereo spectrum can deemphasize the center, thus unbalancing a mix. If you listen closely and move the slider between 0 and 100, you’ll usually find a “sweet spot” that provides maximum width without altering the mix’s fundamental balance.

9. For this song, set the Loudness Maximizer to 30 to provide a useful boost without adding a distorted or unnatural sound. Because the Loudness Maximizer will prevent the level from exceeding 0, you can leave the Output Gain at 0.

   NOTE

   The Loudness Maximizer can increase the apparent loudness for a more “punchy” sound. However, as with the Exciter, you can have too much of a good thing. Excessive maximization can lead to ear fatigue, as well as make the music less interesting by reducing dynamics.

10. Toggle the power button to enable/bypass the effect and listen to the difference. The mastered version has more sparkle, the bass is in proper proportion with respect to level, the stereo image is wider, and there’s been a subjective overall level boost.
    

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