Hello, and welcome to the first installment of my corner of the Bus. I‘d like to see this blog become a place to discuss advances in audio technology, to share tips for using the technology that‘s available, and to make comments about what technology works and what technology doesn‘t (and recommendations regarding what can be done about it). Considering that EM authors often get the scoop on new products before our readers do, it will also be a place for news about hardware and software that might not be on your radar.

Let‘s begin with a tip for Mac users. Anyone who knows me knows that although I use Windows XP when no alternative is available (for example, when I want to run Sony Cinescore or Cakewalk Z3TA+), I am an enthusiastic Mac user and have been since I bought my first Macintosh (the original 128K model) a few weeks after its introduction in 1984.

Computer operating systems do so much in 2006, you might not realize your OS has certain capabilities unless someone points it out. Did you know that Mac OS X can handle as many simultaneous audio channels as you have audio interfaces to provide them? Using Core Audio‘s capability to recognize Aggregate Audio Devices, your Mac will work with two or more audio interfaces as if they were a single device.

If you have more than one audio interface and want to combine their inputs and outputs, begin by installing any appropriate drivers and either connecting or installing the interfaces (if they are class-compliant, no drivers will be necessary). Power them up and then open the application Audio MIDI Setup. Click on the Audio Devices tab and pull down the Properties menu for each interface to specify its Audio Input and Audio Output Format (the sampling rate and bit depth). If you‘re going to use more than one device, make sure they have the same bit depth and sampling rate.

Now select Open Aggregate Device Editor from the Audio menu. When you click on the Add (+) button, you‘ll see a list of available audio devices. (Note that one of the listed devices is Built-in Audio, which means that you can add your Mac‘s built-in S/PDIF ports to the mix, if it has them.) Click on the checkboxes next to the devices you want to include, and select one as the master clock source (note that all interfaces must have a selectable clock source). If you hear anything that might indicate clocking problems, you can click on the Resample checkbox; otherwise, leave it alone. In the System Settings near the top of the window, specify your new Aggregate Device as your Default Input and Default Input, and finally, close Audio MIDI Setup. Open your multitrack audio program and specify the Aggregate Device as your audio system, if necessary. When you go to assign audio channels, you‘ll see that you have more choices than you did before.