Musical Hacks

1490 Articles

bass drum speaker mic

DIY Bass Drum Microphone Uses Woofer Cone As Diaphragm

April 18, 2015 by 17 Comments

Anyone into audio recording knows that recording drums is a serious pain. Mic setup and positioning can make or break a recording session. One particular hurdle is getting a great sound out of the bass drum. To overcome this, [Mike] has built a microphone using an 8″ woofer in an attempt to capture the low-end frequencies of his bass drum. Using a speaker as a microphone isn’t a new idea and these large diaphragm bass drum mics have taken commercial form as the DW Moon Mic and the now-discontinued Yamaha SubKick.

The project is actually quite simple. The speaker’s positive terminal is connected to Pin 2 of a 3-pin XLR microphone connector. The speaker’s negative terminal is connected to the connector’s Pin 1. [Mike] made a bracket to connect the woofer to a mic stand, which in turn was cut down to position the woofer at bass drum height. The setup is then plugged into a mixer or pre-amp just like any other regular microphone.

[Mike] has since made some changes to his mic configuration. It was putting out way too hot of a signal to the preamp so he added an attenuation circuit between the speaker and XLR connector. Next, he came across an old 10″ tom shell and decided to transplant his speaker-microphone from the open-air metal rack to the aesthetically pleasing drum shell. Check out [Mike’s] project page for some before and after audio samples.

Play Robotic Bongos Using Your Household Plants

April 16, 2015 by 2 Comments

[Kirk Kaiser] isn’t afraid to admit his latest project a bit strange, being a plant-controlled set of robotic bongos. We don’t find it odd at all.  This is the kind of thing we love to see. His project’s origins began a month ago after taking a class at NYC Resistor about creating music from robotic instruments. Inspired to make his own, [Kirk] repurposed a neighbor’s old wooden dish rack to serve as a mount for solenoids that, when triggered, strike a couple of plastic cowbells or bongo drums.

A Raspberry Pi was originally used to interface the solenoids with a computer or MIDI keyboard, but after frying it, he went with a Teensy LC instead and never looked back. Taking advantage of the Teensy’s MIDI features, [Kirk] programmed a specific note to trigger each solenoid. When he realized that the Teensy also had capacitive touch sensors, he decided to get his plants in on the fun in a MaKey MaKey kind of way. Each plant is connected to the Teensy’s touchRead pins by stranded wire; the other end is stripped, covered with copper tape, and placed into the soil. When a plant’s capacitance surpasses a threshold, the respective MIDI note – and solenoid – is triggered. [Kirk] quickly discovered that hard-coding threshold values was not the best idea. Looking for large changes was a better method, as the capacitance was dramatically affected when the plant’s soil dried up. As [Kirk] stood back and admired his work, he realized there was one thing missing – lights! He hooked up an Arduino with a DMX shield and some LEDs that light up whenever a plant is touched.

We do feel a disclaimer is at hand for anyone interested in using this botanical technique: thorny varieties are ill-advised, unless you want to play a prank and make a cactus the only way to turn the bongos off!

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bass fire extinguisher

Putting Out Fires With A Dubstep Drop

April 13, 2015 by 47 Comments

Two engineering students from George Mason University have built a rather unorthodox fire extinguisher. It uses a subwoofer to send sound waves powerful enough to extinguish small fires.

Similar in concept to a giant smoke-ring canon, the device uses a subwoofer with a tube that has a smaller aperture opening at the end. When the bass drops (literally), this causes an intense wave of sound (well, air), to be expelled from the device. And as you can see in the video below, it’s quite effective at putting out small fires.

They use a small frequency generator and amplifier to power the system, and throughout extensive testing found 30-60Hz to work best. It’s not actually one big blast of air, but a pressure wave that goes back and forth — agitating the air, and separating it from the fire. There is a catch though.

One of the problems with sound waves is that they do not cool the fuel,” Isman said. “So even if you get the fire out, it will rekindle if you don’t either take away the fuel or cool it.

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Robotic Glockenspiel Crunches “Popcorn”

April 12, 2015 by 14 Comments

[James] sent us a video of his latest creation: a robotic glockenspiel that’s currently set up to play “Popcorn”. It uses eight servos to drive mallets that strike the tone bars with fast, crisp movements. The servos are driven with a 16-channel I²C servo driver and MIDI shield, which are in turn controlled with an Arduino Uno. The previous incarnation of his autoglockenspiel employed solenoids, dowels, and elastic bands.

[Gershon Kingsley]’s 1969 composition for synthesizer “Popcorn” has been covered by many artists over the years, though perhaps the most popular cut was [Hot Butter]’s 1972 release. Check it out after the break, and dig that lovely cable management. We’d love to see [James]’s autoglockenspiel play “Flight of the Bumblebee” next.

If you’re hungry for more electro-acoustic creations, have a gander at [Aaron Sherwood]’s Magnetophone.

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Robot Guitar Rocks Out

Robotic Player Guitar Rocks Out On Its Own

April 11, 2015 by 29 Comments

Back in 1988 [Ben Reardon] walked through the Japanese pavilion at the World Expo held in Brisbane, Australia. He saw a robot playing a classical guitar, and was in awe. Later in his life, he decided to learn guitar, and always thought back to that robot. After going to SIGGRAPH 2014 and being inspired by all the creative makers out there, he realized the technology was here — to build his own Robot Guitar.

He started small though — with a prototype robotic Tambourine. It helped flush out some of the ideas for coding that he would eventually employ on the Robot Guitar. The guitar features both an Arduino and a Raspberry Pi, along with six RC servos — one for each string. The biggest challenge with the project was getting the servos mounted just right — stiff, but with adjustment so each pick could be tuned for identical timing. He ended up using aluminum extrusion to mount the servos, three per side in order to leave space for the picks.

Once the mechanical portion was done — onto the coding…

In the end, it ended up being only 460 lines of code. Python and a bit of Bash for the Raspberry Pi — and of course a few sketches for the Arduino. But enough talking about it — let’s hear it!

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Logic Noise: More CMOS Cowbell!

April 10, 2015 by 23 Comments

Logic Noise is an exploration of building raw synthesizers with CMOS logic chips. This session, we’ll tackle things like bells, gongs, cymbals and yes, cowbells that have a high degree of non-harmonically related content in them.

Metallic Sounds: The XOR

I use the term “Non-harmonic” in the sense that the frequencies that compose the sound aren’t even integer multiples of some fundamental pitch as is the case with a guitar string or even our square waves. To make these metallic sounds, we’re going to need to mess things up a little bit, and the logic function we’re introducing today to do it is the exclusive-or (XOR).

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Trash Can Guitar Cab

Guitar Speaker Cabinet Actually Belongs In Garbage Can

April 5, 2015 by 20 Comments

[Dano] builds a lot of guitar pedals and amps. He needed a speaker cabinet dedicated to this task in order to be a consistent reference when checking out his electronic creations. He ordered a couple of 10″ guitar speakers…. and they sat around for a while.

Then one day at the craft store, he stumbled on an inexpensive wooden trash can. It had a tapered design and came with a lid. As would any normal person, [Dano] immediately thought these would make a perfect speaker cabinet so he bought two of them.

The trash cans would be used in an upside-down orientation. The intended lid makes for a well fitting bottom of the cabinet. Holes were cut for the speaker and two terminal blocks. Since these cabinets would be used for testing a bunch of different amps, two different terminal blocks were used to permanently have multiple connector types available.

A pair of modern kitchen cabinet handles were used as carrying handles for each of the two cabinets. If a speaker cabinet one speaker tall is cool, a cabinet two speakers tall must be twice as cool. To get there, the two cabinets were bolted together using electrical conduit as an industrial looking spacer. Those brackets bolted to the sides of the bottom cabinet are actually Ikea shelf brackets that [Dano] had bought and never used. The Ikea brackets support casters making for easy moving around the studio.

Overall, [Dano] is happy with how his cabinets sound. They are very unique and interesting at the least. We’d be happy to play some riffs through them!