sound

83 Articles

Taking Mechanical Keyboard Sounds To The Next Level

July 13, 2023 by 10 Comments

When it comes to mechanical keyboards, there’s no end to the amount of customization that can be done. The size and layout of the keyboard is the first thing to figure out, and then switches, keycaps, and then a bunch of other customizations inside the keyboard like the mounting plate and whether or not to add foam strips and other sound- and vibration-deadening features. Of course some prefer to go the other direction with it as well, omitting the foam and installing keys with a more noticeable click, and still others go even further than that by building a separate machine to make their keyboard activity as disruptive as it could possibly be.

This started as a joke among [ac2ev] and some coworkers, who were already teasing about the distinct sound of the mechanical keyboard. This machine, based on a Teensy microcontroller, sits between any USB keyboard and its host computer, intercepting keystrokes and using a small solenoid to tap on a block of wood every time a keystroke is detected. There’s also a bell inside that rings when the enter key is pressed, similar to the return carriage notification for typewriters, and as an additional touch an audio amplifier with attached speaker plays the Mario power-up sound whenever the caps lock key is pressed.

[ac2ev] notes that this could be pushed to the extreme by running a much larger solenoid powered by mains electricity, but since this was more of a proof-of-concept demonstration for some coworkers the smaller solenoid was used instead. The source code for the build can be found on the project’s GitHub page and there’s also a video of this machine in action here as well. Be careful with noisy mechanical keyboards, though, as the sounds the keys produce can sometimes be decoded to determine what the user is typing.

Using Sonar To Measure Traffic Speeds

June 19, 2023 by 21 Comments

One of the most common ways of measuring the speed of a vehicle is by using radar, which typically involves generating radio waves, directing them at a moving vehicle, and measuring the various ways that they return to the device. This is a tried-and-true method, but can be expensive and technically complex. [GeeDub] wanted an easier way of measuring vehicles passing by his home, so he switched to using sonar instead to measure speeds based on the sounds the cars generate themselves.

The method he is using is similar to passive sonar in submarines, which can locate objects underwater based on the sounds they produce. After a false start attempting to measure Doppler shift, he switched to time correlation using two microphones, essentially using stereo audio input to detect subtle differences in arrival times of various sounds to detect the positions of passing vehicles. Doing this fast enough and extrapolating the data gathered, speed information can be calculated. For the data gathering and calculation, [GeeDub] is using a Raspberry Pi to help keep costs down, and some further configuration of the microphones and their power supplies were also needed to ensure quality audio was gathered.

With the system in place in a window, it detected around 9,000 vehicles over a three-day period. The software generates a normal distribution of vehicle speeds for this time, with the distribution centered on around 35 MPH, slightly above the posted speed limit of 30. As long as there’s a clear line of sight to the road using this system it’s just as effective as some other passive systems we’ve seen to measure vehicle speed. Of course, active speed measurement systems are not out of the realm of possibility if you’re willing to spend a little more.

Mechanical Keyboard As Travel Saxophone

March 14, 2023 by 9 Comments

Those who play larger musical instruments, things like drums, piano, harp, tuba, upright bass, or Zeusaphone, know well the challenges of simply transporting their chosen instrument to band practice, a symphony hall, or local watering hole. Even those playing more manageably-sized instruments may have similar troubles at some point especially when traveling where luggage space is at a premium like on an airplane. That’s why [jcard0na] built this electronic saxophone, designed to be as small as possible.

Known as the “haxophone”, the musical instrument eschews the vibrating column of air typical of woodwind instruments in favor of an electronic substitute. Based around the Raspberry Pi, the device consists of a custom HAT with a number of mechanical keyboard switches arrayed in a way close enough to the layout of a standard saxophone that saxophonists will be able to intuitively and easily play. Two pieces of software run on the Pi to replicate the musical instrument, one that detects the player’s breaths and key presses, and another that synthesizes this information into sound.

While [jcard0na] notes that this will never replicate the depth and feel of a real instrument, it does accomplish its design goal of being much more easily transportable than all but the most soprano of true saxophones. As a musical project it’s an excellent example of good design as well, much like this set of electronic drums with a similar design goal of portability.

A small electronic board next to colorful stylized speaker

Soundscape Sculpture Is Pleasing Art For Your Ears

January 18, 2023 by 4 Comments

Artist and self-described “maker of objects” [Daric Gill] is sharing some of the world’s most pleasing and acoustically interesting soundscapes with museum patrons in his latest work, ‘The Memory Machine: Sound‘.

Now featured at the Center of Science and Industry museum, the interactive stereo soundscape generator resembles three decorated ‘tree trunks’, suspended high above the exhibition floor. When visitors approach the artwork, they are treated to a randomly selected soundscape sample.

The build, which is described in blog form here, teases just some of the sixty soundscape samples that can be heard. These include the noisy chattering of crowds underneath the Eiffel Tower in Paris, the mellow melodies of a meadow high in the Swiss Alps, and the pumping atmosphere of a baseball match played in Yankee Stadium, New York City.

Only the middle trunk reveals the electronic soul of the installation – an Adafruit M4 Feather Express, Music Maker Featherwing and a motion sensor. The flanking trunks house the speakers and amplifier. The motion sensor triggers the microcontroller, which then plays a randomly selected sample from an SD card.

[Daric] went to great lengths to reuse discarded materials, and even cannibalized parts from other sculptures to see his vision through. This focus underpins a substantial amount of woodworking and machining that went into this build, so the full video is certainly worth a watch to see the whole project come together.

Make sure to check out our coverage of other funky installations, like this mesmerizing ceiling decoration.

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I’ve Got Two Turntables And A Laser Engraver

November 27, 2022 by 29 Comments

Digital media provides us with a lot of advantages. For something like recording and playing back music, digital copies don’t degrade, they can have arbitrarily high quality, and they can be played in a number of different ways including through digital streaming services. That being said, a number of people don’t feel like the digital experience is as faithful to the original sound as it could be and opt for analog methods instead. Creating analog copies of music is a much tougher matter though, as [Marco] demonstrates by using a laser engraver to produce vinyl records.

[Marco] started this month-long project by assembling and calibrating the laser engraver. It has fine enough resolution to encode analog data onto a piece of vinyl, but he had to create the software. The first step was to generate the audio sample, then process it through a filter to remove some of the unwanted frequencies. From there, the waveform gets made into a spiral, accounting for the changing speed of the needle on the record as it moves to the center. Then the data is finally ready to be sent to the laser engraver.

[Marco] did practice a few times using wood with excellent success before moving on to vinyl, and after some calibration of the laser engraver he has a nearly flawless 45 rpm record ready to hit the turntable. It’s an excellent watch if not for anything than seeing a working wood record. We’ve actually seen a similar project before (without the wood prototyping), and one to play records from an image, but it’s been quite a while.

Thanks to [ZioTibia81] for the tip!

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ADSL Router As Effects Pedal

September 8, 2022 by 11 Comments

Moore’s law might not be as immutable as we once though thought it was, as chip makers struggle to fit more and more transistors on a given area of silicon. But over the past few decades it’s been surprisingly consistent, with a lot of knock-on effects. As computers get faster, everything else related to them gets faster as well, and the junk drawer tends to fill quickly with various computer peripherals and parts that might be working fine, but just can’t keep up the pace. [Bonsembiante] had an old ADSL router that was well obsolete as a result of these changing times, but instead of tossing it, he turned it into a guitar effects pedal.

The principle behind this build is that the router is essentially a Linux machine, complete with ALSA support. Of course this means flashing a custom firmware which is not the most straightforward task, but once the sound support was added to the device, it was able to interface with a USB sound card. An additional C++ program was created which handles the actual audio received from the guitar and sound card. For this demo, [Bonsembiante] programmed a ring buffer and feeds it back into the output to achieve an echo effect, but presumably any effect or a number of effects could be programmed.

For anyone looking for the source code for the signal processing that the router is now performing, it is listed on a separate GitHub page. If you don’t have this specific model of router laying around in your parts bin, though, there are much more readily-available Linux machines that can get this job done instead.

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Solar Cells As Art Form

August 31, 2022 by 10 Comments

When most of us approach a project, we have a certain problem to solve. 3D printing, microcontrollers, batteries, and all kinds of technologies are usually tools to accomplish some task. This is not necessarily true in the art world, though, where the intrinsic nature of these tools can be explored for their own sake rather than as a means to an end. The latest one that came across our desk is this light-powered sound generator.

The art piece looks a bit like a mobile with rotating arms, holding various small solar cells each connected to a speaker. As the arms pivot, the light falling on the cells changes which drives a specially-designed circuit connected to a speaker. The circuit acts as an oscillator, passing the changing voltage from the cell through various capacitors and transistors to produce changing tones in the speaker.

The effect of the rotating solar panels is not only oscillations from the speakers as the light changes, but oscillations in the sound of the speakers as they rotate towards and away from the observer. It’s a unique project and perfect for the art show it was in. It’s also not the only sound-focused art installation we’ve ever seen before, be sure to check out this one based on an ESP32.