A Beverage Cooler with a Stereo

Cooler

If you are looking for a way to spice up your summertime parties, try following [Pastryboy's] lead. After letting the idea rattle around in his head for a few years, he finally built himself the cooler he always dreamed of.

[Pastryboy] was originally inspired by a YouTube video he found a few years ago. He took the basic concept and rolled with it. He started out with a mini fridge he found for $10. He removed the compressor and other plumbing bits. He also removed all of the internal shelving. Any leftover holes were patched up with silicone. Now when the fridge is laid on its back, it’s essentially the same as an ordinary cooler.

Next [Pastryboy] purchased two 6.5″ Boss speakers and an inexpensive head unit. He drilled a few pilot holes in the side of the refrigerator and then used a jigsaw to cut the holes to the proper sizes. Once the speakers were mounted in place, he needed to find a way to waterproof the inside. This was accomplished by using some small plastic bowls. The edges of the bowls were attached to the cooler wall using silicone.

[Pastryboy] was able to run most of the cabling through the inside of the cooler’s walls. The system is powered by a 12V lead acid battery. He chose a specific model of battery that can be stored in any orientation and that can handle being knocked around a little bit.

Next he added a couple of handles to the sides to make it easier to transport. A small bit of ski rope was attached to the inside of the lid, preventing the lid from flopping completely open. [Pastryboy] also added a drain to the bottom to make it easier for one person to empty the cooler. The final touch was to pretty it up a bit. He sanded down the entire thing and gave it several coats of red paint. The end result looks very slick.

[via Reddit]

Block Noise, Listen To Music

Noise Blocking headphones made from industrial earmuffs

Noise-Cancelling Headphones actively cancel external sounds so the listener can hear their media without distraction. They do this by taking external sound waves from an on-board microphone, inverting the audio signal and mixing that with the media audio. The outside sounds and their inverses cancel each other out before reaching the listener’s ears. There is one downside to these types of noise-cancelling headphones, they are very expensive.

[Mike] works in a wood shop and didn’t want to pony up the hundreds of dollars it would cost for a pair of noise-cancelling headphones, let alone having such an expensive electronic device in a dusty workshop. The solution? Make some headphones that will block out the noise but still allow the comfortable listening of music. This project is simple but effective; inexpensive headphones taken apart and installed in a pair of Industrial Ear Muffs. If you’d like to make your own, [Mike] gives step by step on the above link.

[Read more...]

Interactive Gloves Turn Gestures into Music

Imogen Heap wearing her Mi.Mu gloves

[Imogen Heap] is a UK-based musician who is trying to change the way we think about making music. She’s been working on a pair of gloves called the Mi.Mu, and they’re getting close to production.

In the included interview she explains that while computers and technology have brought many new advances to music, twiddling dials and pushing random buttons “is not very exciting for me, or the audience”. With these gloves, the artist becomes one with the music and interaction.

The current iteration of gloves use flex sensors along each finger to determine the movement (along with motion sensors for other gestures). She’s been through many designs and hopes to integrate e-materials into the next — using the actual glove as the sensor (not physical flex sensors).

She’s been working with both developers and musicians mapping the various motions of the gloves to music which makes sense in an intuitive way, and it’s very unique to see in action.

[Read more...]

Transcribing Piano Rolls with Python

Piano Roll

 

Perforated rolls of paper, called piano rolls, are used to input songs into player pianos. The image above was taken from a YouTube video showing a player piano playing a Gershwin tune called Limehouse Nights. There’s no published sheet music for the song, so [Zulko] decided to use Python to transcribe it.

First off the video was downloaded from YouTube. This video was processed with MoviePy library to create a single image plotting the notes. Using a Fourier Transform, the horizontal spacing between notes was found. This allowed the image to be reduced so that one pixel corresponded with one key.

With that done, each column could be assigned to a specific note on the piano. That takes care of the pitches, but the note duration requires more processing. The Fourier Transform is applied again to determine the length of a quarter note. With this known, the notes can be quantized, and a note duration can be applied to each.

Once the duration and notes are known, it’s time to export sheet music. LilyPond, an open source language for music notation, was used. This converts ASCII text into a sheet music PDF. The final result is a playable score of the piece, which you can watch after the break.

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Thumbs-Down Songs on Pandora with Your Mind

[Steven] likes music. Like many of us, he uses Pandora to enjoy the familiar and to discover new music. Now, Pandora means well, but she gets it wrong sometimes. [Steven] has had a Mindwave Mobile EEG headset lying around for a while and decided to put it to good use. With the aid of a Raspberry Pi and a bluetooth module, he built a brainwave-controlled Pandora track advancing system.

The idea is to recognize that you dislike a song based on your brainwaves. The Mindwave gives data for many different brainwaves as well as approximating your attention and meditation levels. Since [Steven] isn’t well-versed in brainwavery, he used Bayesian estimation to generate two multivariate Gaussian models. One represents good music, and the other represents bad music. The resulting algorithm is about 70% accurate, so [Steven]‘s Python script waits for four “bad music” estimations in a row before advancing the track.

[Steven] streams Pandora through pianobar and has a modified version of the control-pianobar script in his GitHub repo His script will also alert you if the headset isn’t getting good skin contact, a variable that the Mindwave reports on a scale of 0 to 200.

Stick around for a demo of [Steven] controlling Pandora with his mind. If you don’t have an EEG headset, you can still control Pandora with a Pi, pianobar, and some nice clicky buttons.

[Read more...]

A Guitar From an Old Tin Box

omar-mos

[Atdiy and Whisker], collectively known as  [The Tymkrs] have been busy honing their luthier skills. They’ve created a 10 part YouTube series about the construction of their new cigar box guitar. Instead of a cigar box though, they’ve substituted a 1920’s tin cigarette box. The Omar Cigarette company gave “Project Omar” it’s name. Like [Tymkrs] previous guitar, Omar is a three string affair. The neck was cut from Black Palm, which really shined when polished with a mixture of orange oil and beeswax. They also threw in a couple of new tricks on this build. Omar is an electric guitar, with a pickup custom wound  by [Bob Harrison]. Omar also has frets, which creates a whole new set of complications. Frets are generally installed by cutting slits in the guitar neck with a fret saw. Rather than buy a new tool, [Tymkrs] created a simple jig for their mini table saw. The jig held the guitar neck perpendicular with the saw blade. This made quick work of the many fret slits to be cut. Installed frets must also be dressed and leveled, which is a time-consuming process. 

The tin cigarette box also created a new set of problems. The thin tin proved to be a bit on the weak side when the strings were tightened down. A bit too much pressure on the box while playing would cause notes to bend, much like the tremolo or whammy bar on a standard electric guitar. [Tymkrs] were able to counteract this by adding bracing inside, and a couple of black palm braces to the back of the box.

Hum was also a problem. When [Tymkrs] first plugged in, they found they had more 60Hz mains hum than signal from their strings. Omar uses a classic single coil guitar pickup. Single coils will pick up noise from any magnetic field, including the field created by the studio electrical system. A humbucking pickup uses two coils to counteract this effect. Humbuckers also have a slightly different tone than single coils. [Tymkrs] wanted to stick with their single coil tone, so they counteracted the hum by raising the pickup closer to the strings. Higher pickups receive more signal from the strings, so this is basically a free signal to noise ratio improvement. They also grounded the entire tin box, along with Omar’s metal tail stock. The final build sounds great, as evidenced by the jam session toward the end of Video 10.

[Read more...]

Retrotechtacular: Wax On, Wax Off: How Records Are Made

In this 1942 tour of the RCA Victor plant in Camden, NJ, we see the complete record making process from the master cut production to the shipping of multiple 78RPM shellac pressings. The film centers around a recording of Strauss’ Blue Danube waltz as performed by the 1940s equivalent of studio musicians, the Victor Salon Orchestra.

The master record starts life as a thin layer of molten wax poured on to a hot circular plate in a dust-free room.  Bubbles and impurities are blow torched out, and the wax is left to cool under a steel dome. This perfect disc is carefully passed to the recording studio through a special slot, where it is laid carefully beneath the cutting stylus.

Unlike today’s multi-track recording sessions, the master was cut from the performance of a complete band or orchestra all playing as they would in concert. The sound engineer was responsible for making fast changes on the fly to ensure sonic  and groove width consistency. 

After cutting, the delicate wax undergoes several phases of electrolysis that form the metal master. It is bombarded first with pure gold and then twice with copper sulfate to build a sturdy disc. The copper ionization process also ensures high fidelity in the final product.

Although mighty, this master won’t last long enough to make all the necessary pressings, so a mother matrix is made. This is a negative image of the master. The mother is formed by electrolytically bathing the master in nickel, and then adding a thin film of some indeterminate substance. Another copper bath, and mother emerges. As soon as possible, the master is separated and whisked away to the storage vault.

Since a positive image is needed for pressing, a stamping matrix is made. Mother gets a nickel bath for durability, and then a copper bath to form the stamping matrix. Many stampers are created so that several records can be pressed at once. These images get a chromium plating to help them last through many pressings.

[Read more...]

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