Special effects

Advanced users who want to further tweak Howl's output can apply various interesting special effects (accessed via the player's "magic wand" button). The available options in the special effects menu are described below.

Apply special effects

This is a quick toggle to turn all special effects on or off. When toggled on, any configured special effects will be applied. When toggled off, all the controls in the "Special effects" section are ignored and have no effect on output.

Amplitude feel

Changes the amplitude curve. Values above 1.0 will make more use of higher amplitudes, values below 1.0 will make more use of lower amplitudes. The formula used is amplitude^(1.0/feel), where the original pattern amplitude is a value between 0.0 and 1.0.

Scale amplitude

Allows the amplitude of all output on a channel to be scaled down or up. For example setting scale amplitude to 0.5 will halve the power of the file or pattern so that it does not go beyond 50%. The main purpose of this setting is to assist some Coyote 3 users who found that the output was too strong with certain very conductive electrodes, even with the output power set to the minimum of 1.

Frequency feel

Changes the frequency curve. Values above 1.0 will make more use of higher frequencies, values below 1.0 will make more use of lower frequencies. The formula used is frequency^(1.0/feel), where the original frequency is a value between 0.0 and 1.0 (representing the lowest to highest output frequencies).

Invert frequencies

This inverts all the frequencies on the relevant channel. So if we would have played the lowest frequency, we will instead play the highest frequency (and vice versa).

Frequency adjust

Provides a flat frequency adjustment up or down. For example if we would have played the lowest frequency (0.0) and the frequency adjustment is set to 0.1, we will instead use frequency 0.1, which is 10% of the way up the available frequency range. Large flat adjustments will usually cause significant clipping to the top or bottom of the range.

Random amplitude noise (amount/speed)

Introduces an element of random noise into the amplitude values we output. The easiest way to understand it is to play the "Calibration 1" activity and look at the output chart - you will see it's a nice smooth repeating curve. Now set this control to 0.1, and observe the difference. You'll see that the output follows approximately the same shape, but it's now jagged and bouncy instead of smooth, which will feel different.

There's also a control to set the speed at which our generated noise changes. Higher values will cause it to bounce around more rapidly, and lower values will cause it to bounce around more slowly.

Random frequency noise (amount/speed)

The same concept as the random amplitude noise control, but affects frequency instead. This can be very useful with something like a converted audio file that just sits on one frequency (which is pretty common). By applying some random frequency noise at a slow speed, you can make the frequency shift around in a pleasing way instead.

Order of special effects

The order in which effects are calculated is: pattern from source -> swap channels -> invert frequencies -> apply noise -> feel adjustments -> other scaling and flat adjustments -> output.

We swap channels first so that the other effects always apply to the channel they are labelled with. We do amplitude scaling last so that the control is effective in capping the output to the user's selected value.