Acoustic Levitation With A Twist

January 5, 2017 by Dan Maloney 27 Comments

Don’t blame us for the click-baity titles in the source articles about this handheld “acoustic tractor beam”. You can see why the popular press tarted this one up a bit, even at the risk of drawing the ire of Star Trek fans everywhere. Even the journal article describing this build slipped the “tractor beam” moniker into their title. No space vessel in distress will be towed by [Asier Marzo]’s tractor beam, unless the aliens are fruit flies piloting nearly weightless expanded polystyrene beads around the galaxy.

That doesn’t detract from the coolness of the build, revealed in the video below. There’s no tutorial per se, but an Instructables post is promised. Still, a reasonably skilled hacker will be able to replicate the results with ease straight from the video. Using mostly off the shelf hardware, [Marzo] creates a bowl-shaped phased array of ultrasonic transducers driven by an Arduino through a DC-DC converter and dual H-bridge driver board to boost the 40 kHz square waves from 5 Vpp to 70 Vpp. By controlling the phasing of the signals, the tractor beam can not only levitate small targets but also move them axially. It looks like a lot of fun.

Acoustic levitation is nothing new here – we’ve covered 3D acoustic airbending, as well as an acoustic flip-dot display. Being able to control the power of sound waves in a handheld unit is a step beyond, though.

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Rocking An Acoustic Guitar By Making It Electric

August 3, 2016 by Steven Dufresne 18 Comments

Brothers [Armand] and [Victor] took their acoustic guitar to the next level, making their own pickups to turn it into an electric guitar. The result is that awesome electric guitar sound.

The pickups are homemade magnetic pickups. Each string has a steel bolt behind it with three ceramic magnets on each bolt. A coil is also wrapped around all the pickups. That coil is what’s connected to the wires going to the amplifier. When a string vibrates, it changes the magnetic field in the pickup which induces a current in the coil and that is then sent on to the amplifier to be altered as desired and turned back into sound. Of course that meant the guys had to replace their nylon strings for steel ones.

With just the volume amplified the sound isn’t very different but when the amplifier’s gain is turned up and the volume turned down the sound is undoubtedly electric. As you can hear in the video below, Johnny B. Goode, Paint it Black and Satisfaction take their acoustic guitar’s sound to a whole new level.

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Listen Up: IPhone Hack Diagnoses HVAC

November 30, 2015 by Al Williams 29 Comments

We all know that guy (or, in some cases, we are that guy) that can listen to a car running and say something like, “Yep. Needs a lifter adjustment.” A startup company named Augury aims to replace that skill with an iPhone app.

Aimed at commercial installations, a technician places a magnetic sensor to the body of the machine in question. The sensor connects to a custom box called an Auguscope that collects vibration and ultrasonic data and forwards it via the iPhone to a back end server for analysis. Moving the sensor can even allow the back end to determine the location of the fault in some cases. The comparison data the back end uses includes reference data on similar machines as well as historical data about the machine in question.

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Using MIDI And Magnets To Produce Tones With Tines

November 18, 2014 by Sarah Petkus 18 Comments

Normally you’d expect the sound of a pipe organ to come from something gigantic. [Matthew Steinke] managed to squeeze all of that rich melodic depth into an acoustic device the size of a toaster (YouTube link) which uses electromagnetism to create its familiar sound.

[Matthew ’s] instrument has a series of thin vertical tines, each coupled with a small MIDI controlled electromagnet. As the magnet pulses with modulation at a specific frequency, the pull and release of the tine causes it to resonate continuously with a particular tone. The Tine Organ is capable of producing 20 chromatic notes in full polyphony starting in middle C and can be used as an attachment to a standard keyboard or a synthesizer app on a smart phone. The classic style body of the instrument is made out of mahogany and babinga and houses the soundboard as well as the mini microcontroller responsible for receiving the MIDI and regulating the software oscillators sending voltage to the magnets.

[Matthew’s] creation is as interesting to look at as it is to listen to, so I’d recommend checking out the video below to hear the awesome sound it produces:

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Acoustic Bass Guitar Uses Water Jug And Two Strings

April 7, 2013 by Mike Szczys 18 Comments

water-bottle-acoustic-guitar

It’s easy to dismiss this one at first glance. But once you hear [Tychsen81] playing the thing you’ll want to know more.

He posted the demonstration way back in 2009. It wasn’t until a year later that he filmed the particulars of how the thing was made. The strings are actually bass guitar strings, an A and D string that are tuned down to E and A to play along with Black Sabbath’s “Ironman”. The neck is made out of two boards. One serves as the fingerboard, which is fretless. The other is mounted under that in order to provide negative space for the bridge while keeping the strings at the right height for the fingerboard. The water bottle helps to amplify the sound and that’s why the bottom end of the strings pivot on the bridge, pass through the neck, and are anchored on the bottom edge of the bottle.

We’ve embedded both the demo and the build videos after the break.

If this gets you thinking about making your own instruments you will also be interested in the Whamola.

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Cheap Acoustic Panel DIY

October 21, 2011 by Jesse Congdon 37 Comments

[Eric Wolfram] wrote in to let us know about a simple and cheap acoustic panel DIY he put together. When installing a home theater acoustics are often neglected (especially if you spend so much on the TV you cannot afford any furniture for the room) resulting in reduced listening quality and poor spacial sound imaging from your surround system (also responsible for the furniture problem). The addition of sound absorbing panels helps control the acoustics of the room and may even class up the place a bit. These are also come in handy for home studio usage where a low level of reverberation is preferred.

The panels are relatively simple to produce on a budget, just a sheet of 2″ thick dense fiberglass board glued into a wooden frame and covered in a sound-transparent fabric. [Eric] goes into a lot of the material selection process to help you along your way. The best part about the project (aside from its obvious utility) is that all of the materials can be found cheaply at your average home improvement store, with the exception of the fabric. [Eric] mentions that you can substitute colored burlap if need be. Once the panel is assembled and glued it just has to be hung on the wall of your choice like a large heavy picture frame. This could certainly help the acoustics and reduce some slap-back echo in your warehouse/shop. We might have to try this one over the weekend.

Thanks [Eric]!

What Input Device? Just Use Your Arm

March 31, 2010 by Mike Szczys 24 Comments

This one could be a game changer. [Chris Harrison] and a team of researchers are showing off a method of using your arm as an input device. An arm band worn by the user picks up acoustic signatures created by tapping on your arm with the other hand, or taping your fingers and thumb together on the same hand. They’re achieving accuracies in the 82-97% range but it gets even better. Take a look at the video after the break and see what they’ve done by adding a pico-projector to the arm band in order to use your arm or hand as a touch display.

We liked seeing the concept mice from October, but the future of input devices might already be attached at the elbow.

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