Unified · Split
| @@ -8,22 +8,12 @@ continue using whatever paremeter was chosen last. This · 7 unmodified lines | |||
| 8 | creates a certain kind of resistance that is very useful | 8 | creates a certain kind of resistance that is very useful |
| 9 | for swellling effects, which is where it gets its name. | 9 | for swellling effects, which is where it gets its name. |
| 10 | 10 | ||
| 11 | At the core of this is a recursive one-pole smoothing | ||
| 12 | filter, which requires one sample of filter memory. | ||
| 13 | |||
| 14 | The alpha coefficient is used to compute the filter. It is | ||
| 15 | computed from one of the smoothing parameters which are in | ||
| 16 | tau units. | ||
| 17 | |||
| 18 | The previous sample is held. This is used to analyze | ||
| 19 | whether or not to go up or down. | ||
| 20 | |||
| 21 | An inertia filter is included in this design to allow for | 11 | An inertia filter is included in this design to allow for |
| 22 | changes between the two smoothing states to be more | 12 | changes between the two smoothing states to be more |
| 23 | gradual. This is another one pole smoothing filter, applied | 13 | gradual. This is another one pole smoothing filter, applied |
| 24 | to the signal switching between the two smoothing times. | 14 | to the signal switching between the two smoothing times. |
| 25 | 15 | ||
| 26 | To sumarize the topology of this filter design: Swell is a | 16 | To summarize the topology of this filter design: Swell is a |
| 27 | one-pole smoothing filter whose smoothing factor is | 17 | one-pole smoothing filter whose smoothing factor is |
| 28 | determined by the direction of the input signal, placed | 18 | determined by the direction of the input signal, placed |
| 29 | through another one-pole smoothing filter for inertial | 19 | through another one-pole smoothing filter for inertial |
| @@ -37,7 +27,7 @@ struct. Otherwise, it is opaque. · 7 unmodified lines | |||
| 37 | The struct for swell is called =sk_swell=. It is | 27 | The struct for swell is called =sk_swell=. It is |
| 38 | initialized with =sk_swell_init=. The sampling rate is | 28 | initialized with =sk_swell_init=. The sampling rate is |
| 39 | required. | 29 | required. |
| 40 | * Components | 30 | * Filter Components |
| 41 | There are two recursive one-pole IIR filters known as the | 31 | There are two recursive one-pole IIR filters known as the |
| 42 | smoothing filter and the switching filter. Both require 1 | 32 | smoothing filter and the switching filter. Both require 1 |
| 43 | sample of filter memory, as well as a coefficient used to | 33 | sample of filter memory, as well as a coefficient used to |
| @@ -46,7 +36,7 @@ compute the filter. · 2 unmodified lines | |||
| 46 | Swell takes in three parameters: smooth factor A, smooth | 36 | Swell takes in three parameters: smooth factor A, smooth |
| 47 | factor B, and inertia. | 37 | factor B, and inertia. |
| 48 | 38 | ||
| 49 | Set smoothign factor A with =sk_swell_smootha=. | 39 | Set smoothing factor A with =sk_swell_smootha=. |
| 50 | 40 | ||
| 51 | Set smoothing factor B with =sk_swell_smoothb=. | 41 | Set smoothing factor B with =sk_swell_smoothb=. |
| 52 | 42 | ||