Bells and Whistles
On this page, we’ll explore some odds and ends that can make the pipe more interesting.
Shaping the breath noise
Our model’s breath noise is pretty drab: we can control the level, and have a basic tone control in the Noise module’s Color control. But that’s it. Some additional EQ would be welcome.
One quick and easy solution is the Vocal Filter. It’s a one-module solution that can shape the noise into various vowel sounds. It has a frequency control, a resonance control, and can morph between up to three different vowels. Quite a lot for a single module. Below is a patch that uses it.
Growling is when a wind instrument player interrupts the air pressure into the instrument at a fast rate, typically 15 to 30 Hz.
Growling is similar to vibrato, and we’ve already implemented vibrato on a previous page. Below is a patch that growls. The LFO controls the rate, and the “Growl Amount” knob controls the amount.
Controlling amplitude with velocity
Controlling amplitude with key velocity seems like a simple thing. But there’s occasionally a complication on the G2: when playing from note to note on a monophonic patch, velocity differences can sometimes be so sudden that they can make an audible click in the sound.
To compensate, we’ll add a small amount of glide into the system. Because it’s common to use the Velocity morph to control a panel knob that controls patch volume, we’ll make our patch compatible with this.
In the patch is below, the “Output Level” knob controls the patch’s volume, and is connected to the keyboard velocity morph group. But the audio signal doesn’t go through this knob. Instead, the knob simply controls a DC voltage which is used to control a VCA. A Glide module between the knob and the VCA protects us from clicks if there are large changes in velocity from note to note.
Chiffing overtones during the attack
A neat sound is when a wind player briefly overblows on a note’s attack, causing a short higher-mode vibration. Our model doesn’t have this ability built into it, but it’s not difficult to add.
The patch below demonstrates one method. It uses a Noise Oscillator to generate the chiff. A Noise Oscillator combines a noise source and a tunable bandpass filter in one module. It can also track the keyboard, and is ideal for our purpose. We can adjust the pitch of the chiff, and how focused the pitch is, using just one module.
This goes through an envelope generator to shape the attack/decay characteristics, and then through a level control. We’ll feed the chiff into the model at the mouthpiece.
Since the Noise Oscillator lets us adjust the pitch of the chiff, how should we set the pitch? It turns out that most setting won’t produce much of a chiff at all! The reason is that the pipe itself only lets a few favored pitches through: odd harmonics, the ones that correspond to the harmonic series of a square wave.
The first pitch the pipe lets through is the fundamental. That’s not a very interesting-sounding chiff, so we’ll ignore it. The second favored pitch is the 3rd harmonic, which is three times the frequency of the fundamental, or +19 semitones. That makes a pretty good-sounding chiff. The next favored pitch is the 5th harmonic, which is five times the frequency of the fundamental, or +28 semitones. Our patch is set to the 3rd harmonic.
For added measure, we’ll control the volume of the chiff from the keyboard velocity. The patch is below.