SRC: Software Conversion Part IV

In 1989, I started the Pacific Coast Sound Works in my garage in Chatsworth, California. It was a service company that specialized in recording, editing and mastering audio. I had already purchased Digidesign’s Sound Tools hardware and application for my Mac Plus computer. However, it became immediately apparent that it was incapable of doing professional level work. This predecessor to the ubiquitous Pro Tools DAW was not much more than a curiosity and toy at in 1989. It was time to look for something better.

Some months before, my close friend Peter Otto and I were hired to work on a CD for a contemporary music ensemble based at The California Institute of the Arts. We were all graduate students in the music department and the recording was done in one of the halls at the school. We hauled my 3M 56 2-inch 16- track analog machine tot he school and set it up in one of the electronic music studios. The plan was to record throughout the weekend. The piece was “Hoketus” by Louis Andriessen, a contemporary Dutch composer, a very insistent, minimalist work with insanely challenging metric and notational requirements. There’s a much larger story than can be shared here about the difficulties Peter and I encountered during that weekend…but I’ll just say it was as close as I’ve ever come to abandoning a project in mid stream. Just listen to the piece on YouTube and imagine trying to record all of the parts in one track at a time.

Anyway, we recorded the entire album and went search about for a pre-mastering facility to edit the compositions together and prepare a Sony 1630 Umatic master tape for the replicator. I found out about the Digital Brothers. They were operating a small digital pre-mastering business out of their folk’s home in Orange County. They had one of the very first Sonic Solutions DAWs. In fact, it was so new that it wasn’t even a production board…theirs was a prototype wire wrap version stuffed into a Mac II computer. This was the tool I was looking for.

I went home and discussed the options with my wife and decided that the Pacific Coast Sound Works was going to have to upgrade to the Sonic system. I was a full time employee at CSU Northridge (half faculty member and half music department technician) and was running PCSW on the side. After seeing what the Digital Brothers and a few other mastering facilities were doing, I knew it was time to move away from analog recording and editing and into the age of digital audio. It was the right decision.

Converting between 48 and 44.1 kHz sample rates on Sound Tools and Sonic Solutions couldn’t have more different. On Sound Tools, you would load the audio from a DAT tape onto the hard drive at the original sample rate and then invoke a SRC process to plow through the existing file and create a new file at the target sample rate. This meant that you had to have twice the hard drive space (in an era when hard drive space was very expensive). While the conversion was taking place, a progress bar was displayed on the screen of the Mac Plus and a very large number slowly counted down to zero. Sample rate conversion in Sound Tools (and eventually in Pro Tools) took a very long time AND occupied the entire machine…you couldn’t do anything else while the file was being created.

The Sonic Solution architecture was very different from Sound Tools. The addition of a dedicated sound card with its own RAM and heavy duty DSP chips meant that SRC could be done in real time…during the loading of the file. That’s right. I could tell the machine to load 1 hour of 48 kHz digital audio from my DAT machine AND click on a button that would convert the 48 to 44.1 kHz while the load was happening. In addition, the load could happen in the background allowing me to continue working on other programs. The difference couldn’t have been more dramatic. This was a professional level tool.

Most professional mastering houses adopted sonic Solutions as their preferred mastering tool. Its ability to accomplish sample rate conversion in software while in real time was a huge improvement over other systems.

And there was more…