Scream and Scream Again

Posted by Mattias on 2006-01-06 in Tutorials

Oh, the Horror…

Discovering Part6 1

There’s a new breed of Reason FX units in town, and they’re not to be messed with. The most lethal weapon of them all is the Scream 4 Sound Destruction Unit. Sure, it can play nice, gently warming up your sounds with a smooth tape saturation algorithm – but underneath the innocent facade lurks an audio assassin, a mad mangler that will tear your sounds to shreds and leave no one alive to tell the tale. Dare you read on?

Distorted Reality

Scream 4 is arguably one of the best sounding and most versatile distortion units in the software domain. It’s capable of producing very realistic, natural distortion. But distortion comes in many shapes and sizes; even though the term in a musical context has become somewhat synonymous with the rock’n'roll-type distortion produced by a guitar amplifier pushed over the edge, the term encompasses much more than that. As a dictionary would have it, distortion is “the act of twisting something out of natural or regular shape”. Some of the ten Scream 4 algorithms can not be attributed to analog or “real world” distortion emulation, they’re something different altogether: Modulate, Warp and Digital. Here’s a quick recap of the different algorithms (described in full detail in the Reason 2.5 Operation Manual, page 226):

  • Overdrive produces an analog-type overdrive effect. Overdrive is quite responsive to varying dynamics. Use lower Damage Control settings for more subtle “crunch” effects. Overdrive is the quintessential “pleasant” distortion, the kind that analog gear produces when pushed to the limit and beyond. It was discovered in the infancy of rock’n'roll – in the 1950s, guitar amps were usually low powered (5 to 35 watts) and easily frightened. This was long before guitar amplifier manufacturers had any idea that this was a desirable way to use an amp – they would have referred to it as abuse.
  • Distortion is similar to Overdrive, but produces denser, thicker distortion. The distortion is also more “even” across the Damage Control range compared to Overdrive. This algorithm appears to emulate transistor distortion which is more of a 1980s heavy metal type deal.
  • Fuzz produces a bright and distorted sound even at low Damage Control settings. This is the angry, wasp-like 1960′s Jimi Hendrix effect. An obtrusive buzzing sound with little to no low end.
  • Tape emulates the soft clipping distortion produced by magnetic tape saturation and also adds compression which adds “punch” to the sound. This is the algorithm for anything you need to “de-digitalize” – individual instruments or the entire mix.
  • Tube emulates tube distortion. Tube distortion is warmer, thicker and more musically appealing than transistor distortion. Tube amplifiers (originally called “valve” amps) were the original guitar amplifiers, later to be replaced by transistor amps, but soon resurfaced and remains the ‘gourmet’ choice to this day.
  • Feedback combines distortion in a feedback loop which can produce many interesting and sometimes unpredictable results. Feedback is basically when a sound source is fed back to itself.This algorithm is great fun, but you need something that controls the P1 and P2 parameters to fully appreciate it.
  • Modulate first multiplies the signal with a filtered and compressed version of itself, and then adds distortion. This can produce resonant, ringing distortion effects. Also called Multiplicative Synthesis, this effect is quite common on synthesizers (the Subtractor, for instance) but gets especially interesting when used on a natural sound such as a vocal or acoustic instrument sample.
  • Warp distorts and multiplies the incoming signal with itself. Watch Star Trek for more information.
  • Digital reduces the bit resolution and sample rate for raw and dirty sounds or for emulating vintage digital gear. This effect has so many potential applications, from emulation of crusty old arcade game samples to Aphex Twin type “digital meltdowns” where the entire mix is sucked into a vortex of pixelated audio.
  • Scream is similar to Fuzz, but with a bandpass filter with high resonance and gain settings placed before the distortion stage. The cool thing about this algorithm is the bandpass filter. You can control its frequency with the P2 knob (or connect the Auto CV out to the P2 CV in) to produce a heavy wah-wah effect.

Basically, you should try to forget all the conventions about distortion, since: A) You can distort anysound, not just guitar, and B) The Scream 4 is more versatile than most distortion effects. Drums, bass, vocals, pads – anything goes. Here’s a quick example of what the Scream 4 can do for a Vocoder sound – an excerpt from the Reason 2.5 Flash showreel.

Since the Scream 4 is pretty straightforward we will not go over different examples of effects in this article – a wide range of Scream 4 presets is featured in the In Full Effect Sound Bank that installs with Reason 2.5. Instead, we will look at one of the “hidden” features – the Auto envelope follower which is a new type of CV signal source, previously unavailable in Reason and very useful for all sorts of tricks.

Grand Theft Auto

The Auto section of the Scream 4 is so useful that one simply has to steal it, or at least borrow it. You can use this even if you’re not employing the Scream 4 as an actual effect. If you start thinking about scenarios where you’d like the volume (or inverted volume) of one sound to control something, you’ll soon come up with a lot of possibilities. How about dynamic control of the detune parameter on the UN-16 Unison – the louder the sound, the heavier the detuning? Or how about controlling the Shift parameter on a Malström? Building your own compressor? There are hundreds of possibilities. Here are a few examples:

Ducking. You can send the Auto CV through a Spider CV and invert the signal. This means that the higher the amplitude of the input sound, the lower the Auto CV value. This application can be used for a “ducking” effect, i.e. when the volume of one sound source increases, the volume of another source decreases. In the example file duckandcover.rns, we’re using two Dr. REX units playing different drum loops. Increasing the volume level on one Dr. REX will “drown out” the other – but in this case, not completely; whenever there is silence between the drum loop slices on the governing Dr. REX, the “slave” Dr. REX will slip through. Try increasing the reverb decay or the delay feedback in the example file and you’ll get the picture.

External source Auto Wah. How about letting a second source control the wah effect? For this we need two sound sources and one Scream 4 unit. In the example file blabbermouth.rns we use a ReDrum as a source signal for the Auto section of a Scream 4 unit which in turn controls the cutoff frequency on a Subtractor. Since in this case we don’t want a distortion effect on the ReDrum, we can either turn off all the effect sections on the Scream 4 (the auto CV out will be operational anyway), or we can use a Spider Audio to split the signal from the ReDrum, send one stereo signal to the mixer, and the other to the Scream 4 where it’s “terminated”. As a bonus, you will find one more Scream 4 unit in the example file: This one is used as an effect on the Subtractor, and it’s also using its Auto CV output to control its own P2 parameter. The signal is inverted through a Spider CV, and the P2 parameter on the “Scream” algorithm controls a resonant bandpass filter, meaning that we get an “inverse wah-wah”. Check it out.

ECF-42 Wah. If you can’t seem to get quite the wah effect you’re after, using the Auto section on the Scream 4 alone, you might want to try heavier artillery. The ECF-42 Envelope Controlled Filter might be your cup of tea. Soopah_wah.rns is an example of such a setup, where the ECF-42 is in bandpass mode. It can be tricky to get the Auto section working right, but in 9 out of 10 cases the problem is that the signal is too high, causing the envelope follower to fly wide open – consequently, you don’t get a “wah” but rather a “weeeeeeeh” effect. There are different ways to remedy this problem, but a good place to start is to lower the volume level on the input source, i.e. the instrument. The Scream 4 can compensate for low levels, because it has some gain headroom; to “calibrate” the Scream 4, switch off Damage, Cut and Auto. Then set the Master pot to 100 (which is not the maximum volume; 127 is). Switch between On and Bypass and you’ll find that there is no difference. Now you can experiment with the Auto section and perhaps lower the volume of the source sound; use the Master gain to compensate. If you’re using Auto CV and get the same problem, use the CV adjustment pot on the target device to dampen the signal.

Bottom line

It’s a killer device, no doubt. It’s also a chameleon and highly useful as an insert effect on just about any instrument in the rack. You don’t always have to use it at full blast, it can do wonders even at near unnoticeable settings. Don’t set it loose unsupervised.

Text & Music by Fredrik Hägglund

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