How the plate material changes a keyboard's sound
Updated
The stiffer the plate, the brighter and louder the board: steel, brass and aluminium give a sharp clack, while polycarbonate, POM and polypropylene flex and give a deeper, more muted sound. FR4 and carbon fibre sit in between.
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Pick a pack, then press any key or tap the keys below. These are the same samples the app plays.
Plate materials, stiff to soft
| Material | What KeebsForAll says about its sound | Feel |
|---|---|---|
| Steel | “Loud, clear sound: Produces a sharp ‘clack’”; “Metallic ping: Can create unwanted resonance or ringing” | “The most rigid material with no flex” |
| Brass | “Warm, resonant sound: Produces a satisfying ‘clack’ with depth”; “May produce a ‘pingy’ sound if not dampened” | Heavy; “Great for tactile switches” |
| Copper | “a resonant tone with pronounced upper frequencies”; “Noisy” | Heavy, solid |
| Aluminium | “High-pitched sound: Produces a bright tone that might lack the warmth some users prefer” | “firm, predictable” |
| Carbon fibre | “Sharp sound profile: Some may find its acoustics harsh or overly bright” | Light and stiff |
| FR4 | “Mid-toned sound: Produces a ‘thocky’ sound that’s neither too loud nor too muted” | “Moderate firmness” |
| POM | “Smooth, ‘creamy’ sound”; “Good sound absorption” | “Slightly firmer than PC” |
| PC | “Rich ‘thocky’ sound: Absorbs vibrations to create a muted, satisfying sound” | Cushioned; “May feel wobbly” |
| PP | Not described for sound | “the softest plate material” |
KeebsForAll’s summary: soft plates give “a cushioned, quieter typing experience”, stiff plates “firm feedback and crisp sound”. Epomaker’s Sound Lab agrees in fewer words: “Aluminum and brass ring brightly; PC and POM absorb and soften.”
The plate never works alone. The same plate sounds different screwed to the case or floating on gaskets (see gasket mount), and foam under it takes away part of its ring (see foam mods).
Stiff and soft in Teclo’s packs
Teclo models the plate and case together as one struck body with many resonances, each dying away at its own rate. Knuckle imitates an unlubed board on a steel plate, and its body is the stiffest in the app: 18 resonances reaching up to 8,500 Hz, where each octave up rings about 0.7 times as long as the one below it, against half as long in Butter. Butter, on gaskets and foam, has 14 resonances that stop at 5,250 Hz. Boulder shows the case’s share: its body rings 200 ms before falling to about a third, against Butter’s 60 ms. Those are the model’s settings in Teclo’s source code; what the rendered files measure:
| Pack | What it imitates | Brightness (Hz) | 90% of energy in (ms) |
|---|---|---|---|
| Knuckle | Tactile, unlubed, steel plate | 3,653 | 11.3 |
| Butter | Linear, lubed, on gaskets and foam | 2,479 | 13.1 |
| Boulder | Linear in a heavy aluminium case | 2,428 | 18.1 |
Knuckle is the brightest keyboard pack Teclo has. The packs imitate the effect of a stiff or a soft build; none is a recording of a particular plate, and Knuckle also differs from Butter in its lube and its switch, so you hear a whole build, not the plate alone.
For the other parts of a board, start at why mechanical keyboards sound different.
Questions
Which keyboard plate is the most thocky?
The soft plastics. KeebsForAll describes a PC plate's "Rich 'thocky' sound" that "absorbs vibrations", and FR4's "thocky sound that's neither too loud nor too muted". Epomaker's recipe for a marbly sound picks PC and says "POM and FR4 are too soft; aluminum too bright."
Why does my keyboard ping?
Usually an unlubed spring, by Epomaker's glossary, but stiff metal plates add to it: KeebsForAll warns that brass "May produce a 'pingy' sound if not dampened" and that steel "Can create unwanted resonance or ringing".
Does the plate matter more than the case?
They work together. Epomaker says the plate "transfers and reflects switch energy" and that the mount decides "whether energy dissipates into resonance or stays a sharp impact"; the case is "the acoustic chamber".
Sources
Other facts on this page come from these pages, read on or before the date above.