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.

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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]

The Last HOPE has just released a list of all the schedule talks at the conference. 97 different talks will be divided over three tracks during the course of the three day conference. It looks like a lot of interesting events will be going down. The Cold Boot encryption attack tools will be released. Representatives from Graffiti Research Lab will be showing The Complete First Season and unveiling their One Laser Tag Per Child system. Virgil Griffith from WikiScanner will be mining even deeper into the wretched hive of scum and villainy. Karsten Nohl will present why hardware obfuscation is an impossibility and how they defeated the MiFare crypto. The Last HOPE will be in New York City July 18-20, 2008

Time to look way back into the Hackaday archives, well back to 2005 at least. This is a new feature to follow up and revisit some of our favorite projects of the past. Our first installment includes the week of May 24-31 2005.

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.