KeyslamBuckling spring · sound test
Buckling spring sound test: a Unicomp keyboard
The sound of a Unicomp buckling-spring keyboard, recorded by SamsterBirdies with a clip-on BOYA BY-M1 and released as CC0. Unicomp builds new boards on IBM's Model M design. Press a band to hear the click-clack from a light tap up to a slam.
Updated
Short answer: A buckling spring keyboard sounds like a loud, springy click-clack: a snap as the spring under the key buckles, a hard clack at the bottom, and the spring straightening again on the way up. This pack is a Unicomp board, from the company that still makes keyboards on IBM's Model M design, recorded by SamsterBirdies and released as CC0. It is cut into 46 takes in four strength bands.
Buckling spring sound test
Each button plays real strikes from one strength band of this recording. Natural mix lets every key vary, like normal typing. Headphones help.
Press a band to hear “spring clack” typed on Unicomp strikes from that band, then type below.
About this recording
- Keyboard
- Unicomp, model not named
- Switches
- Buckling spring over a membrane (Unicomp's Model M design)
- Keycaps
- Not stated
- Recorded by
- SamsterBirdies on Freesound
- Source
- Typing on a keyboard
- Uploaded
- October 22, 2019
- Original file
- FLAC, 24-bit, 44.1 kHz, stereo, 2:16
- Microphone
- BOYA BY-M1, a clip-on lavalier microphone
- Part used
- 0:00 to 2:16
- License
- CC0 1.0 (public domain)
- In Keyslam
- 46 takes, 6 of them key-up
“Recording typing on a Unicomp buckling spring keyboard with a BOYA BY-M1 for over a minute” — SamsterBirdies, on the Freesound page (checked November 2, 2026)
How a buckling spring makes its sound
Each key sits on a coil spring standing upright in a plastic barrel. The spring is held between the keycap and a small pivoting hammer. As you press, the spring first squashes evenly, then gives way sideways all at once. That buckle is the snap you feel in your finger, and it tips the hammer down so the key registers. On the Model M design that Unicomp builds, the hammer strikes contacts on a plastic membrane sheet. On IBM's older Model F, the hammer works over a capacitive circuit board instead.
So one keystroke stacks up several sounds: the snap of the buckle, the clack of the keycap reaching the bottom, and the spring straightening as the key rises. The coil can also ring faintly inside its barrel. Owners call that “spring ping”, and some lube their springs to quiet it. IBM's buckling-spring patents go back to the 1970s, with the cheaper membrane version following in the 1980s, and it's still the sound many people picture when they hear “clicky keyboard”.
Measured from the app's pack files
What the Unicomp buckling spring pack contains, band by band. Peak is the median take's loudest sample; audible length is how long it stays within 30 dB of that peak. Soft to slam spans 10.4 dB. How the bands are made.
| Band | Percentile of strikes | Regular-key takes | Space, Return, Delete | Median peak | Audible length |
|---|---|---|---|---|---|
| Soft | 8th–30th | 6 | 4 | −15.9 dBFS | 78 ms |
| Medium | 38th–62nd | 6 | 4 | −11.5 dBFS | 78 ms |
| Hard | 70th–88th | 6 | 4 | −10.0 dBFS | 67 ms |
| Slam | 92nd–100th | 6 | 4 | −5.5 dBFS | 67 ms |
Unicomp and the IBM Model M sound
IBM started making the Model M in 1985. In 1991 its keyboard production went to the newly formed Lexmark, and when Lexmark stopped making keyboards in 1996, a group of its employees bought part of the keyboard manufacturing assets and started Unicomp, based in Lexington, Kentucky. Unicomp kept building keyboards on the tooling it took over from Lexmark until 2020, when it replaced that worn tooling and shipped a board it sells as the New Model M.
So a Unicomp shares the Model M's membrane buckling-spring switch and its basic construction. It is still not a vintage IBM, and this uploader doesn't say which Unicomp they typed on, so we treat the pack as a buckling-spring sound from the Model M family, not as a recording of any particular IBM keyboard. For the capacitive branch of the family, play the Model F pack.
What this recording adds
SamsterBirdies uploaded 2 minutes 16 seconds of typing in October 2019, saved as a 24-bit, 44.1 kHz stereo FLAC file. In the takes, though, its two channels come out effectively identical, so any width you hear in the app is added by Keyslam, which pans each key toward its side of the keyboard. The description names the maker, the switch and the microphone. The page's tags add “ibm”, “old” and “vintage”, but nothing on it gives a model or a year, so the pack is named after the maker.
A session that long gave the slicer plenty of clean strikes: six regular-key takes per band, 4 per band for Space, Return and Delete, and 6 key-up takes, 46 in all, the most the pack builder keeps by default. The original has a little steady hiss between strokes. Each take is short and faded out, so in the app the click-clack covers it.
Unicomp vs MX Blue and the Model F
Start with Cherry's clicky switch, then the other buckling spring. The figures in the table are read from each pack's own files.
- MX Blue: Cherry's clicky switch, which gets its click from a plastic jacket rather than a spring. The two spectra are fairly close, so the giveaway is the ring: at medium strength this pack's takes stay within 30 dB of their peak for 78 ms, against 58 ms for the Blue.
- Model F: IBM's earlier buckling spring, read through a capacitive board instead of a membrane, on a keyboard from the early 1980s. Someone else recorded it and doesn't say with what microphone, so listen for the shape of each strike rather than its exact tone.
| Pack | Type | Recorded by | Soft to slam | Audible length (medium) | Hear it |
|---|---|---|---|---|---|
| Unicomp | Buckling spring | SamsterBirdies | 10.4 dB | 78 ms | |
| MX Blue | Clicky | EricsSoundschmiede | 12.0 dB | 58 ms | |
| Model F | Buckling spring | Fractal_ | 9.3 dB | 73 ms |
Who it suits
Pick Unicomp if you learned to type on an old IBM-style keyboard and miss it, or want a keystroke with real weight and spring behind it.
Pick something else if other people can hear your desk: buckling springs are about as attention-grabbing as keyboards get. Topre and the Laptop pack are much gentler, and the Model F gives you a buckling spring with a different edge.
Unicomp buckling spring: questions
Is this an IBM Model M?
Not as far as the source says. The uploader describes “a Unicomp buckling spring keyboard” and names no model. Unicomp makes its keyboards on IBM's Model M design, with the same kind of membrane buckling-spring switch, so the sound belongs to the Model M family, but we don't claim the board is an IBM Model M.
Model M vs Model F: how do they sound different?
Both use buckling springs. The Model M, and Unicomp's boards after it, register a key when the hammer strikes a membrane; the earlier Model F reads it through a capacitive circuit board. Collectors usually describe the Model F as crisper and louder. Keyslam's Model F pack is a separate recording by another uploader, so the A/B on this page sets one real keyboard against another; it isn't a lab test of the two switch designs.
Does pressing harder change a buckling spring's sound?
Less than in most of Keyslam’s packs. However hard you push, the spring gives way at the same point, so extra force mostly shows up in the clack at the bottom. Here the slam takes peak 10.4 dB higher than the soft ones, a soft-to-slam gap that is the 12th widest of the 15 packs, and the soft takes sound mostly like quieter versions of the slams rather than a different kind of strike.
Why is this pack called Unicomp and not Buckling Spring?
Because Keyslam has two buckling-spring packs, this one and the Model F. Each is named for what its uploader says it is: “a Unicomp buckling spring keyboard” here and “an IBM Model F XT” on the other.
Keep exploring
Hear a Unicomp buckling-spring board on every keystroke.
$3.99 once after a 7-day free trial. On MacBooks with the motion sensor it follows how hard you type; on other Macs you pick the strength.