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Achieving the perfect acoustic signature for your mechanical keyboard often requires more than just good switches and keycaps; it requires acoustic tuning. Sound dampening mods are essential for eliminating unwanted case ping and hollow echoes that can ruin an otherwise excellent keyboard.
Case foam, typically made of high-density Poron or EVA, is placed in the bottom of the keyboard to absorb high-frequency noises and create a deeper, more muted sound. Plate foam sits between the PCB and the switch plate, reducing the sound of the switches bottoming out. Another popular and inexpensive mod is the “Tape Mod” (or Tempest Mod), which involves applying layers of masking tape to the back of the PCB.
This simple trick acts as a low-pass filter, reflecting lower frequencies back up and giving the keyboard a signature “poppy” or “marbly” sound. The number of tape layers applied directly affects the sound; more layers result in a more pronounced effect. Many builders start with two to three layers and adjust from there based on their preference.
Silicone fills are another advanced modification where liquid silicone is poured into the empty space inside the keyboard case. Once cured, the silicone adds significant mass and completely eliminates any hollow resonance. This mod is permanent and dramatically changes the weight and feel of the board, so it should only be attempted by experienced builders. Combining these mods allows builders to fine-tune their boards to their exact acoustic preferences.