Multichannel Audio Decoder
A device to bridge consumer digial audio sources with professional audio equipment
This device was my senior project at Brigham Young University. I worked in a partnership with Shawn Nageli, a senior at the University of Utah. We were co-workers at Harman Music Group in Sandy, Utah, at the time and we were looking for something interesting to do for our senior project. We both had interests in consumer and professional audio gear and we recognized that few professional audio processors could easily connect to consumer audio digital sources, specifically multichannel S/PDIF data over an electrical coaxial connection or an optical TOSLINK connection. This is because surround sound data such as Dolby Digital or Digital Theater System (DTS) usually travels from the source (such as a DVD player) to a receiver unit that decodes the multichannel signal, converts it to an analog, and amplifies it for the speakers all in a single unit. Professional audio setups are more discrete with separate audio processors, decoders, and amplifiers.
We decided that we could use what we had learned at Harman to create such a device. Shawn is a hardware engineer so his job was to design the schematcs and audio circuits. My specialty was embedded software so I wrote all the software for the device. We demostrated the device at the Wilkinson Student Center at Brigham Young University. Below are a few pictures from our demonstration. Unfortunatly I don't have any video or audio, but it wouldn't do much good because I just can't recreate the sound of being surrounded by five professional powered speakers. Imagine the sound in a nice digital surround-sound movie theater.
Here is a picture of Shawn and me with the box:
Here is a picture of our demo setup. You can see our device sitting atop two dbx DriveRack 4800 units (a popular professional audio processor developed by dbx). The audio travels from the DVD player via an optical TOSLINK cable into our unit. The Dolby Digital signal is then decoded into standard professional digital audio pairs and sent to the DriveRack units. The DriveRack units convert the audio to an analog signal and pass it to the five JBL Eon powered speakers.
Here is a diagram of the system in the box and where it fits into the demo setup:
This is what the back of the unit looks like:
