The Scream 4 uses acoustic models to emulate many different types of distortion. Like the RV7000, its adjustable parameters change according to what model is selected.
First let's look at the three analog distortion models: Overdrive, Distortion, and Fuzz. They sound different but have identical parameters.
To use the Scream 4 analog model
With the instrument of your choice selected, choose Create > Scream 4 Distortion to insert a Scream 4 (Figure 8.47).
Figure 8.47. The Scream 4 Sound Destruction Unit (shown here, front and back) is a good distortion effect.
With your track playing, turn the Damage Control knob clockwise to hear the Scream's default setting of Overdrive distortion (Figure 8.48).
Figure 8.48. The Damage Control knob determines how much gain goes into the distortion model.
The Damage Control knob, like the D-11 Amount knob, boosts the level of the incoming signal. It doesn't affect the character of the distortion, only how much distortion occurs.
To adjust Overdrive tone, turn the P1 knob left (darker) or right (brighter) (Figure 8.49).
Figure 8.49. The P1 (parameter 1) knob controls different things for different models. For the Overdrive model it controls tone.
Adjust the Overdrive presence using the P2 knob.
Presence is a pre-distortion tone control that affects midrange. It affects the tone (more presence means brighter), but it also affects the character of the distortion. High presence is harsher, and sometimes punchier.
Use the Damage Type knob to pick from the other two analog distortion models:
Distortion is denser and more severe in the high frequency range than Overdrive.
Fuzz is more severe in response to the Damage Control knob than the Distortion knob.
The Scream 4 also models the distortion produced by vacuum tubes, such as you would find in a guitar amplifier.
Tubes clip in a distinctive way: They let in less sound as they fill up. This variable sensitivity to incoming sound adds a small amount of compression to clipping, for a mellower distortion.
To adjust the Tube damage type
With your loop playing and a Scream 4 inserted, set the Damage Type knob to Tube.
Use the P1 knob to adjust tube contour, which sounds like a subtle high-pass filter. Think of contour as a frequency response curve that the P1 knob shifts up and down.
Use the P2 knob to adjust the tube bias. Bias involves a tube's "resting" state, or how its response to signals gets focused. The P2 knob will subtly alter the character and harmonic content of the distortionthe middle P2 setting is like a 20/20 focus.
The Scream 4 Tape damage type models the way that recording tape saturates. Like the Tube model, it adds compression, accepting less sound when more sound is coming in.
To adjust the Tape damage type
With your loop playing and a Scream 4 inserted, set the Damage Type knob to Tape.
Use the P1 knob to adjust the tape speed.
Remember that with tape, the faster the tape speed, the more particles per second available and the higher the resolution (i.e., more high frequencies).
Use the P2 knob to adjust the amount of compression.
In this case, compression refers to soft clipping, characteristic of how tape responds to an overloaded signal.
Compression vs. Distortion
Distortion is a raw excess of capacity that clips sharply, adding harsh harmonics. Compression uses a gate with a fade-in (attack) and fade-out (release) that sets a maximum shelf and regulates how sound levels impact it. Thus clipping is minimized and unruly peaks keep a rounder shape.
Compressors can also boost low-level sounds by increasing the overall signal level without spilling over the top. (For an explanation of Reason's MClass Compressor, see Chapter 11, "Mastering.")
Beware of overcompressing a signal. A signal that is so loud that most of its peaks have to be gated will lose its louds and softs. Instead what you'll hear is the gate opening and closing with no apparent relation to the pulses in the music, as if someone's messing with the vol-ume knob.
Judiciously used, compression can help you hear as much sound as possible in the most situations, both emphasizing low-level sound that would otherwise be buried in a mix (expanding) and making sure the loudest peaks don't get pushed too high in the process (limiting).
Feedback simulates a feedback loop, such as when a microphone is placed next to a speaker playing the microphone signal back to itself. As the signal gets amplified more signal plays backeventually building to a sustained, wailing noise pattern.
The parameters won't make much sense unless you are feeding a signal into your Scream 4 and can listen to the effects, so be sure you have at least a test loop set up.
To adjust the Feedback damage type
With your loop playing and a Scream 4 inserted, set the Damage Type knob to Feedback.
The P1 (size) knob adjusts the timing between the source signal and the signal feeding back; the results will be unpredictable, so you'll have to experiment.
Use the P2 (frequency) knob to control the center frequency, or wailing tone of the effect.
Modulate is another unpredictable effect that will require some experimenting to get a feel for. This distortion model filters and compresses the incoming signal, and then applies it to the original for some ringing distortion effects.
To adjust the Modulate damage type
With your loop playing and a Scream 4 inserted, set the Damage Type knob to Modulate.
Use the P1 (ring) knob to adjust the effect's filter resonance.
Use the P2 (frequency) knob to adjust the filter's frequency. High P2 values will make the sound harsher and more piercing.
The Warp model copies the signal, distorts it, and then combines it with the original. This causes the original signal and the distorted signal to cancel each other out, emphasizing the distorted effect and the resulting overtones.
To adjust the Warp damage type
With your loop playing and a Scream 4 inserted, set the Damage Type knob to Warp.
Increase the P1 (sharpness) knob to get more overtones for a harsher sound, and decrease it for a softer effect.
Increasing the P2 (bias) knob will phase out the cancellation effect, allowing more of the fundamental (input) sounds to remain.
The Digital damage type models lo-fi digital gear, producing a "dirty" or "vintage" sound (depending on your perspective).
To adjust the Digital damage type
With your loop playing and a Scream 4 inserted, set the Damage Type knob to Digital.
In Digital mode, the Damage Control knob determines how much of the dry signal is re-sampled. If you want to affect all of the incoming signal using this model, set the Damage Control knob to maximum.
Use the P1 (bit) knob to reduce bit depth, or "crush" the dynamic range. The full right position leaves the bit rate of the signal alone; full left gives you "1-bit," or no dynamic range at all, just on or off.
Use the P2 (rate) knob to set how much sample rate reduction you want. Sample rate affects high-frequency response. The lower the sample rate, the lower the highest frequency. The full right position leaves the sample rate alone.
The Scream model adds a resonant filter to a fuzz-like distortion. Like the Feedback model, this effect can be used for distortion that has a prominent tonal, wailing quality to it.
To adjust the Scream damage type
With your loop playing and a Scream 4 inserted, set the Damage Type knob to Scream.
Increase or decrease the P1 (tone) knob to brighten or deaden the tone.
Use the P2 (frequency) knob to set the frequency for the high-resonance filter.