20 Ames St.
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David Merrill
MIT Media Lab
20 Ames St.
E15-313
Cambridge, MA 02139
(617) 253-5027
«directions»
[research]
20 Ames St.
E15-313
Cambridge, MA 02139
(617) 253-5027
«directions»
[research]
Main >> Research and Coursework >> AudioPint
Build your own AudioPint!NOTE: The most up-to-date information on building an Audiopint can be found at audiopint.org.A Post-IAP Workshop being held at the MIT Media Lab on Saturday, February 3 2007, organized by:David Merrill..and generously supported by VIA Technologies, Inc. Background :: Generation 1, "Development" AudioPintThis is the first version of the AudioPint that was created. It is built with a VIA EPIA SP 13000 motherboard, 512MB of ram, Ubuntu 'Dapper Drake' Linux and a silver-colored briefcase. Using a PCI audio card connected with optical cable to a standalone audio interface, it supports 8-channel IN and 8-channel OUT. This is the system that supported six performers at SIGGRAPH 2006, each recording, looping, scratching, pitch shifting and otherwise manipulating their own voices. It also went to the Consumer Electronics Show in January 2007, and into the Lewis Music Library at MIT for a week-long show later the same month.
Being an early version, we learned a lot with this one. It has high-quality audio capabilities, but requires a lot of heavy gear (not shown) including the 8-IN, 8-OUT interface, and microphone preamp/compressors. Overall it's not as portable as the original AudioPint vision specified. Progression :: Generation 2, "JellyBean" AudioPintThis is the first AudioPint that is practical to drag all over the place to actually gig with. It has become more compact, more colorful, and more like a real piece of audio gear - but still playful and based on open technology. This is the AudioPint that we are going to be building at the workshop. As you can read below, there are variations on this setup that we can reccommend and help you out with.
The philosophy behind the JellyBean AudioPint is to make the AudioPint more portable and cheaper, while still preserving the important elements that make the AudioPint worthwhile in the first place: flexible programmability, durability, and good quality audio. Making your own JellyBeanWe know that there could never be a single AudioPint configuration that would be optimal for everyone. Luckily, since the AudioPint is an open, hackable audio processing system, it's far easier than with most commercial audio products out there to 'roll your own' AudioPint, so to speak.. The basics: This is the set of materials that are likely to be needed by any Gen-2 AudioPint out there. We have provided estimated costs for each, to give you an idea of what it will set you back to create your own audio-processing platform of the future:
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Some Extras that you might want to consider:
- USB pass-thru for breaking out USB ports to the outside of the box.
- USB-MIDI dongle..
The above table shows the basic parts needed by any AudioPint system, but there are a few other thing that you'll need to make your system usable for your desired application. Below are some 'recommended configurations' and what we estimate each would cost you to make:
Configuration 1 :: Stage quality vocals or instrument preamplification, with XLR and 1/4" input capabilities. This is the configuration that a single-person PureJoy system would utilize. The preamp/compressor is the preferred input signal chain for vocals, and the XLR or 1/4" connector means that you can plug a "real" stage microphone like a SM58 into it.
| part (incl. URL) | price (in USD) | notes |
| XLR and 1/4" connector | $2.50 | This will allow you to connect either an XLR mic, or a 1/4" mic-level instrument cable (from an electric guitar, for example) - in either case, the audio will go through the preamp and compressor. |
| Extra stereo 1/4" connector | $1.50 | This will allow you to plug a stereo line-level signal into your AudioPint if you want to, by routing the other side of this connector directly to your USB audio interface. |
| Mono 1/4" connector (x2) | $1.25 | These are for your outbound, line-level audio signals. |
| Preamp / Compressor | $100 | This will keep vocals in an appropriate range, and will provide the necessary preamplification for an instrument-level signal (from an electric guitar, or an acoustic with a pickup) Also - some people really like the 'warm' sound of tube amplification.. To understand this more fully, check out this paper. |
| Line-level USB audio interface - also, consider the more versatile Griffin iMic. | $29.95 | This line-level USB audio interface will accept the output from the compressor, or from any line-or-headphone-level device - like a CD player or iPod, etc.. |
| total: about $140 | ..which brings the total cost of your AudioPint to about $285 - still less than the Pod XT! |
Configuration 2 :: General Vocal / Instrument (cheaper) This would feature a USB solution that has both preamplified XLR inputs and 1/4".. We thought that the M-Audio Fast Track USB would do the trick, but we couldn't find enough evidence that it works under linux.. If you find a USB device that you think would do the trick, please email us - thanks.
Configuration 3 :: El Cheapo. This one is the absolute minimal cost that still gives you USB audio. USB audio is important because it gives you low latency, as well as decoupling your signal from the electronic noise that can be present on a motherboard's built-in audio.
| part (incl. URL) | price (in USD) | notes |
| Mono 1/4" connector (x3) | $1.25 | These are for your inbound (mono) mic level input, and for your outbound (stero), line-level audio signals. |
| Griffin iMic | $40 | Known to work in linux |
| HE-280B USB Audio Adapter | $10 | This is cheap!.. WE DO NOT YET KNOW IF THIS WORKS IN LINUX |
| total: $15-50 | Note: MAKE SURE YOU GET A USB AUDIO INTERFACE THAT IS KNOWN TO WORK UNDER UBUNTU/DEBIAN! (check here, search for 'audio' then search for 'sound' and you'll find most of the devices that are known to work...) |
Configuration 4 :: No extra audio hardware.. In this configuration, you will use the built-in audio hardware on the mini-itx motherboard itself. You may hear noise from the CPU, memory, video processing engine, etc.. BUT - it's a fine way to get started and try out your AudioPint capabilities. In this case, you'll probably still want to pick up some 1/4" connectors to bring the audio out to the outside (but you don't even have to do this, if you want to plug directly into the motherboard itself.. not recommended, as you may eventually break these connectors.. We will have some extra 1/4" sockets at the workshop) - but otherwise, you don't need to spend any more money above and beyond what is covered in "the basics"..
Email dmerrill@media.mit.edu for questions, concerns, comments, etc..