Here’s a fiery project which [Patrick] calls his Pyro Jam Can. It’s the simplest Rubens’ Tube build that we can think of. For the uninformed, a Rubens’ tube uses flammable gas to reveal wave forms passing through the supply vessel. In the past we’ve seen projects with multiple columns, which very clearly show a standing wave. But this version lacks the resolution for that, so the wave is seen as a modulated flame height.

You can see the propane feed tube coming into the can from the right. This keeps the gas flowing steadily, but a diaphram on the bottom of the can made of a latex balloon allows for modulations in flame height by pushing the gas through the aperture a bit faster than it is flowing. A speaker in the base bounces sound waves off of the diaphragm for the effect seen in the video clip after the break.

We wonder if the can will ever heat up enough to melt the balloon on the other end?

This naked speaker is the basis for [MaoMakMaa's] newest project called the Wavedrone. He plans on using the autonomous and cable-less device during street performances. You can hear the effect of some stretched jazz cords being played on it in the video clip after the break. The sound is kind of an ethereal background noise that observers might not immediately realize is there.

You can see the 9V battery which serves as the power source clinging to the frame of the speaker. A 7805 linear regulator tames that battery and feeds the two IC’s on the circuit board seen to the right. The ATtiny85 is reading music from an SD card and playing it back in mono (obviously) with the help of an LM386 audio amplifier chip. The trimpots that go into the high pass and low pass filters in between the microcontroller and amplifier allow for a bit of sound manipulation, but we’re more impressed with the quality of the sound this is getting when properly trimmed.

The theory behind speaker operation is pretty simple. There’s a coil that is attached to some type of diaphragm and a permanent magnet. When electrical signals pass through the coil a magnetic field is generated, and that field’s interaction with the permanent magnet causes the diaphragm to vibrate and create sound. But we’ve always assumed that the vibrating material must be stretched tight for this to work. [Hannah Perner-Wilson] proved us wrong by making this speaker out of fabric. It uses conductive tape as the coil on a heavy piece of canvas. The permanent magnet is resting on a table and for the demonstration the fabric is just laid on top.

Check out the video after the break to hear the sounds generated by this device as well as a design that uses conductive thread instead of tape. This gets us wondering if what we’re hearing is the result of the magnet vibrating against the tabletop? Let us know your thoughts, and if you’ve got any information about the paper-backed circuit (seen at 0:04 into the video) driving the speakers we’d love to hear about that too.

[Thanks Mowcius]

It looks like this low-end Sennheiser HD speaker has the same internals as it’s better-brother but has been altered to reduce sound quality. It’s not uncommon for manufacturers to hobble a product in order to sell more units at a lower price that reflects less features. Linksys WRT54G routers immediately come to mind, or perhaps the more recent Rigol 100 MHz oscilloscope hack is a better example.

In this case, that black piece of foam on the left has been added to the 555 version of the hardware to decrease the sound quality you get from the much more expensive 595 model. Take it out and you’ve got an upgrade that would have cost you more than a hundred bucks. Don’t think this is the only difference? There is a bit of a difference in case design, but [Mike Beauchamp] also found that if you acquire a replacement driver for either model you’ll get the same part.

The oil can capacitors of the Crossover had gone bad, so a new set of metalized polypropylene capacitors were ordered to pick up the task. After carefully removing the old caps, [Anthony] assembled the new set on a breadboard, and mounted the board to the old Crossover base (along with some tasteful McDonalds straw spacers). The entire process is detailed on his blog, and we are sure his friend saved a good deal by this home repair method. Capacitor issues are a common problem in repairing electronics new and old alike, and always a great place to start looking when devices start acting funny.

While there are many ways to produce audible sound, Plasma Speakers have to be one of the coolest. Usually very complex and expensive, we received a tip for a beginners guide to making one of these impressive novelties. Handily included are a set of schematics (one very simple schematic, the other with a few artistic illustrations). There are also a set of warnings, which include sound advice to mind the heat generated by the MOSFETs, as well as making sure that your input signal isn’t too strong. The finished product is fun to listen to, so be sure to check out the example video after the break.

[Carnivore] tried to break as many (unofficial) records as possible when he modified his Apad/M002 into what he calls Project Apex. Record number 1: [Derek] claims this is the first Apad mod, ever. Record number 2: 8500mAh battery, giving the device a 12 hour life which is longer than any other Android slate. Record number 3: beautiful factory-looking finish. Okay, so that last one isn’t really a record, but we thought Project Apex deserved it anyway. There are a few other modifications done to the device as well; click the link or catch a video of him showing off the slate after the jump.

[Thanks Derek Hughes]

While we could be content following our “kiddie d-day” as [Caleb Kraft] suggested. We know you can’t continue such an awesome Friday without trying to blow yourself up first.

This Wiimote Rubens’ tube caught our eye. A PVC Aluminum irrigation pipe is drilled with holes and propane is pumped through. A speaker on one end creates changes in pressure and a neat light show follows suit. [ScaryBunnyMan] went further though, with a collection of software and a Wii Remote he “plays god” controlling the music, and thus, the fire. Check out a fun video after the split.

[Via Make]

These speakers play different audio tracks depending on which orange square the sit atop. They’re RFID aware and the orange tiles are tags. If you get tired of a track just move the speaker to a different one, or place the speakers next to each other to play the same song. We’re sure there’s a project for us here, it’s just going to take some thinking to figure out what we want to do with it. But the concept is certainly intriguing. Check out the video demonstration after the break.

[Thanks Ferdinand]

A few weeks ago we saw [Jaroslaw's] universal credit card spoofer. Now he’s sent in a project that incorporates an amplifier into a center speaker for use with an iPod or any device with an audio jack.

The build has two main components; an LM4950 audio amplifier and a center channel speaker he picked up for $3 at Goodwill. The circuit used is straight from the datasheet and he’s provided the four necessary resistor values for you in his writeup. An old set of headphones was butchered for the audio connector and DC power can be provided by any 6-12V source.

The final circuit was built on some protoboard. The speaker housing has plenty of room to fit everything in for a nice finished look. Pretty simple, and except for the IC, this should be an easy salvage project for most folks.

We’ve seen some crazy speaker builds in the past (massive folded horns for example). [DiscoJones] wanted to build a set of speakers that could reach very low frequencies and be very efficient. Instead of constructing a large box, he built a baffle that could be placed in a doorway and use the blocked off room as an enclosure. It has eight 12inch subwoofers, eight midrange drivers, and four tweeters. The speakers are fairly cheap and he built a simple crossover to help them work a little better together. The goal was always deep bass though, so don’t expect very high fidelity from a setup like this.

The Griffin AirCurve Dock is a nifty gadget that uses a coiled horn to increase the volume of your iPhone’s speaker. Griffin’s marketing claims that their passive device delivers “amazing amplification” and “you’ll swear there are full-sized speakers in there.” Meh. It does look like an interesting project for someone with a 3D printer. You could experiment with different passage and dock shapes. At least it gives us an excuse to post two massive DIY horns.

Above is “THE BIGGEST SUB HORN OF THE WORLD”, created by the guys at Royal Device. This massive subwoofer and horn is claimed to have bandwidth below 10Hz, and produce 100dB at only 1 Watt of input power. The sub construction is built under the listening room. The speakers (16 of them) are rated for a total power of 6400 watts.

The Kleinhorn is set more in reality. These Baltic birch horns are loaded with Lowther DX-55′s. The horns are about 11 feet long, and were built in sections to make it easy to modify the damping and so you could get them through a door. Our table saws are already itching for some action.

[via Gearlog]

You can make pretty much anything a speaker by vibrating it. Japanese engineer, [Keiji Koga], has been working for many years to perfect his plant based sound transmission system. The voice coil is at the bottom of the plant container and transfers sound up the stalk to the leaves. It’s and interesting idea, but we can’t imagine it sounds much better than vibrating a rigid surface.

[via io9]

Pictured above we see one of the amazing cable braiding machines from UK based Cobra Machinery. This link was found on a post about creating your own high end speaker wires from cat5 cable. At the time we hoped to find a DIY braiding machine. No such luck today but we did come across and interesting site in the process. diyAudoProjects has a ton of great how to guides for all things audio. They even have a few walkthroughs for creating your own speaker wires.

We looked at the robotic dexterous hand from The Shadow Robot Company. Browsing through their high rez image gallery its pretty clear to see the product has been progressing nicely: 24 degrees of freedom complete with force feedback and a GPL based software package.

Three years ago we covered the Nokia 770 internet appliance and it’s upcoming SDK. The device has now been replaced by the Nokia N810 (pictured on the right). However, open source support from Nokia has continued to develop. We found a blog from software developer Ari Jaaksi where he talks about Nokia’s involvement in the community. Recently he discussed the latest news from MAEMO, the platform used for open source development of Nokia internet tablets and other Linux-based devices.