Adjust RC4 S3 Dimmer PWM Frequency (firmware v71 or higher)

These instructions apply to all RC4 Series 3 Harmonized Design devices with firmware versions 4.071 / 2-71-x.x or later.  Applicable devices include:

  • RC4Magic Series 3 and RC4Magic-900 DMX2dim, DMX4dim, DMX4dim-500
  • LumenDim4, LumenDimM4
  • W-DIM4, W-DIMm3

PWM Frequency Selection is a Long-Press Button Feature,and the selected frequency is confirmed using Patterns of Two LEDs.  These are described in detail in

To cycle through available PWM frequencies:

  • Ensure live DMX data is streaming in by either wire (miniplug input) or wireless.

If DMX data is not streaming, the Set buttons act as dimmer bump buttons only.

  • Long-Press SetB.
  • When the LED blink pattern appears, release SetB.  The next PWM frequency is now selected for all dimmers on the device and saved.

The LED blink pattern indicates the frequency as outlined below.  Each long-press of SetB advances to the next frequency.  Advancing from the last option returns to the first option:

Option 1: 615Hz (default) DimA
 16-bit (65,536 steps) DimB  ●
Option 2: 1250Hz DimA
 15-bit (32,768 steps) DimB  ●
Option 3: 5kHz DimA
 14-bit (16,384 steps) DimB  ●  ●
Option 4: 10kHz DimA
 13-bit (8,192 steps) DimB  ●
Option 5: 20kHz DimA
 12-bit (4096 steps) DimB  ●  ●
Option 6: 40kHz DimA
 11-bit (2048 steps) DimB  ●  ●

Lower frequencies are more efficient and deliver higher power handling with less heat.  Higher frequencies avoid banding and other visual artifacts when captured with video equipment.  615Hz provides the smoothest dimming when perceived by the human eye.

When capturing video, do a camera test and select the lowest frequency that is free of visible artifacts.  Higher PWM frequencies are required for higher frame-rates.  You can try this at home with an iPhone or other high-resolution digital video camera — capture video and experiment with different PWM frequencies.  You can see the difference higher frequencies make.

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