Stabilizers, sound, and how a keyboard becomes 'thocky'

Open YouTube comments on any custom keyboard video and you'll see the same word: thock. It refers to a deep, full sound on every keystroke — no rattle on the spacebar, no high ping from springs, no hollow echo from the case. Achieving it is mostly about stabilizers and how the board is assembled, not the switches themselves.

What stabilizers do

Long keys (spacebar, shift, enter, backspace) press a single switch in the middle but need to stay level all the way across. Stabilizers are small assemblies under each long key: a wire connecting two satellite housings, each holding a stem that follows the keycap. They keep the cap from tilting if you press it off-center.

When stabilizers aren't done well, they introduce rattle (the wire clicks against the housing), tick (the stem hits the housing on bottom-out), or sluggishness (the keycap binds against the stabilizer stem). The rest of the keyboard can sound perfect — long keys will give it away.

Stabilizer types

Plate-mounted (clip-in): The stabilizer clips into the metal plate above the PCB. Easy to remove for keycap changes; harder to tune because the plate flexes. Common on entry-level keyboards.
PCB-mounted (screw-in): Stabilizers screw directly into the PCB. The standard for enthusiast and custom boards. More rigid, easier to lube and re-seat. Removing keycaps doesn't disturb them.
PCB-mounted (snap-in): PCB-mounted but with snap clips instead of screws. Cheaper, slightly less rigid than screw-in. Found on mid-range prebuilts.

The big four stabilizer mods

Standard enthusiast modifications, in approximate order of impact:

Lube the stabilizer wire with dielectric grease where it meets the housing. Eliminates wire rattle. The single highest-impact mod.
Lube the stems with a thicker grease (Krytox 205g0 or XHT-BDZ) on the contact surfaces. Smooths the motion.
Apply 'holee mod' or 'band-aid mod' — a thin strip of fabric bandaid or PE foam under each stabilizer stem to cushion the bottom-out and dampen tick.
Clip the legs off the stabilizer stem with flush cutters. Removes the small downward 'tickering' sound caused by the legs hitting the PCB. Irreversible — do this last and only if you know what you're doing.

Tip

Many modern enthusiast keyboards (Keychron Q-series, Mode designs, GMMK Pro) ship with stabilizers already lubed. Test the long keys before tearing the board down — you may not need to mod anything.

Plate material

The plate sits between switches and case, providing structural support and influencing both feel and sound.

Aluminum: Default for most modern boards. Stiff, slightly bright sound. Easy to manufacture in any colorway.
Brass: Heavy, very stiff, deeper sound. Premium feel. Tarnishes slowly over years if uncoated.
Polycarbonate (PC): Plastic, softer, deeper and more muted sound. Visually transparent — popular for RGB show-through builds.
POM: Soft plastic, very flexible. The bounciest plate material, contributes to a 'creamy' feel.
FR4 (PCB material): Fiberglass plate. Quiet, soft, no metallic ring. Used in many enthusiast 75% boards (Mode Sonnet, Bauer Lite).
Carbon fiber: Light, stiff, distinctive sound. Niche but premium.

Mounting styles

How the plate (and PCB beneath it) attach to the case determines how much the assembly flexes when you press a key. Flex = bounce = absorbed energy = deeper, less hollow sound.

Tray mount: PCB screws directly into standoffs in the case. Stiff, no flex, often hollow-sounding. Most budget keyboards.
Top mount: Plate screws into the top half of the case. Some flex, balanced sound. The traditional enthusiast choice.
Gasket mount: Plate is sandwiched between rubber/silicone gaskets, isolated from the case. Maximum flex, softest typing feel, deepest sound. Now standard in mid-to-high prebuilts (Keychron Q-series uses gasket mount).
O-ring mount: Plate floats on O-rings rather than screws. Similar bounce to gasket. Common in NK_ designs and several Mode boards.
Leaf-spring mount: Plate sits on tiny leaf springs. Most pronounced bounce. Used in some Mode and CannonKeys designs.
PCB mount (plateless): No plate at all — switches mount directly to the PCB. Maximum flex; very specific sound. Found in some 40% and 60% boards.

Foam, tape, and dampening

Case foam: Foam in the bottom of the case to absorb echo. The simplest sound mod; most modern boards ship with it.
Plate foam: Thin foam between the plate and PCB. Cuts hollow plate ring at the cost of slight typing feel.
Switch pads: Tiny foam circles around each switch on the PCB. Reduces metallic ring further.
Tape mod: Strips of painter's tape applied to the underside of the PCB to reflect more high-frequency sound back up. Famously discovered by accident in 2021; gives a 'poppier' sound. Polarizing — some hate the harshness it adds.
PE foam mod: A sheet of polyethylene foam between switches and plate. Produces a marshmallow-y, deep 'poppy' sound. Currently the trendy mod.

Note

Sound mods are intensely personal and many cancel each other out. Add one mod at a time, type for a few hours, then decide whether to keep it. There's no objectively best sound.

Lube and the switches themselves

After stabilizers, the biggest sound improvement is switch lube. Hand-lubing each switch (a few hours of patient work) eliminates spring ping (the metallic vibration of the spring) and the scratchy slide of stem against housing. Most modern enthusiast switches come pre-lubed; cheap switches do not.

If you bought a prebuilt with stock switches and want better sound, two cheap options before lubing: (1) swap in pre-lubed enthusiast switches like Akko V3 Cream Yellow Pro or Gateron Oil Kings; (2) just put a pair of o-rings under each keycap (sold as 'silencer kits') — softens the bottom-out without disassembly.