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.
[denha] has assembled a noise box he calls the XR-NOISE using an XR-2206 multi-waveform function generator. The output has an impressive number of controllable settings, and uses a set of LEDs to indicate sound level and rate. The XR-NOISE uses 1/4″ jacks for both in and out, and can also be controlled by the tap-sensitive mic located on the front of the box. Unfortunately, there doesn’t seem to be any further documentation or schematics to provide context, but it seems that this function generator chip has also been used for other audio hack projects as well, including a scratch-synth using resistive pressure sensors.
[Patrick] has a pair of Klipsch speakers that continually needed the volume knob cleaned. After a bit of research, he found it was a common problem with the potentiometer chosen for the task. He decided to resolve the problem, not by replacing that potentiometer, but by modifying the speakers to be passive and running them from an external amp. While this does sound simple at first, he wanted to retain the rest of the electronics in the unit, so a bit of hacking was required. You can follow along through the whole process on his site.
Dallas/Maxim’s DS1801 is an audio volume potentiometer with a simple SPI interface. This chip has two channels of volume control that might be useful in a DIY audio project. We previously looked at the DS1807, a similar part with an I2C interface. This week we’ll show you how to use the SPI version.
The DS1807 contains two logarithmic digital potentiometers (pots) for audio volume adjustment. Each pot has 64 volume levels plus a mute setting. The volume level of each pot is set over a two-wire I2C serial interface. We’ll show you how to connect and interface the DS1807 below.
The fine folks at Midnight Research Labs have put together a new toy for you to play with. It’s a Python script that makes your WiFi hardware behave more like a theremin. Based on the pyaudio library it monitors the signal strength of the AP you’re connected to and changes the tone accordingly. There’s a sample embedded above (direct link). If you have a second interface, you can use it to modulate the volume. It’s an interesting trick, but they say that there’s enough latency that it would be hard to play actual music with it.
Bug Labs, the company that makes modular electronics that allow you to build your own tech doohickeys quickly and easily, has announced five new modules: BUGprojector, a mini DLP projector developed in conjunction with Texas Instruments, which sounds very much like the tiny DLP projector we posted about last week; BUGsound, an audio processing module with four stereo input/output jacks, a microphone, a speaker, and builtin hardware codecs; BUGbee (802.15.4) and BUGwifi (802.11 and Bluetooth 2.0+EDR), which will let you connect wirelessly with your PAN and WLAN, respectively; and BUG3g GSM, for connecting to (you guessed it) 3G GSM networks. In conjunction with Bug Labs’ existing series of modules, especially the highly versatile BUGvonHippel universal module, you’ll be able to create some pretty kickass gadgets. No word yet on pricing, although Bug Labs expects to ship by the end of Q1 2009.
Advanced Beauty is a collection of 18 “sound sculptures” pairing artists and programmers to create a collaborative work visualizing sound. The styles run a broad range from fluid simulations to manipulating cell animation. The demos were built using Processing. While all of these were built using human input, we see potential for them to help improve standard visualizers. Hopefully, to bring out more information about what’s actually being played. Below is just one of the videos in the series. You can find more on Vimeo. Read the rest of this entry »
German designer [Michael Schoner] of NL Architects turned an ordinary street bench into a public sound system that can be accessed by passersby with iPods and cellphones with Bluetooth. Boom Bench features 60 watt co-axial speakers, two subwoofers, and a bass shaker in the seat that’ll allow you to feel the vibrations of your music choices. It was on display in Amsterdam last month for the Urban Play event. It remains to be seen whether this new urban development will make your daily wait for the bus more entertaining or aggravating.
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.
