Podcast Academy

Many of us use Mackie mixers for various aspects of production work-flows. Mackie is one of a select group of established gear manufacturers that have managed to secure a brand new target user base. Of course I am referring to podcast producers who are willing to spend a few extra dollars when purchasing high quality gear. This is no surprise to me. Mackie products speak for themselves.

I personally own/use the Onyx 1620, and the 1402-VLZ Pro. These mixers are a bit different, however there is one unique feature that to the best of my knowledge is available on all Mackie mixers: the ALT 3-4 Bus. I’m finding that this option or feature is the source of some confusion within the community. I think you will be surprised to hear how straight forward this option is, and how useful it can be.

First, let me point out that the control button responsible for activating the ALT 3-4 Bus on all Mackie mixers serves a dual purpose:

• channel mute
• bus routing

You will also notice a set of 1/4 inch “ALT 3-4″ outputs, located somewhere in your patch bay on your console. Keep in mind that these are “outputs”.

If nothing is connected to the ALT 3-4 outputs in the patch bay, the engaged “Mute/ALT 3-4” push-button simply mutes that channel. Well Greg Mackie concluded that this was a wasted signal path. Subsequently, he decided to create an extra stereo bus that would provide the engineer with an extra set of outputs that would be independent of the main mix. This bus would be activated using the same dual purpose button located on each channel strip. The ALT 3-4 Bus was born.

Simple, yes? Well, it depends. There are a few interesting methods of possible implementation. For example: I use the ALT 3-4 Bus on my console to create a Skype mix-minus. This is similar in concept to a mix-minus created when using an AUX Send bus. Essentially, this is a one directional output path that does not contain the main mix.

I use a Mac G4 Powerbook for Skype. The G4 system output feeds a set of line inputs on my console. This allows me to hear Skype. The trick is to send my voice [studio mic] back to the G4 - minus Skype. The solution is simple: activate the ALT 3-4 Bus on my mic channel, and route this output back to the computer. In this case I am feeding the computer input my voice minus Skype as previously noted.

In specific situations, creating a ’sub-group’ is also possible using the ALT 3-4 Bus. The purpose of a sub-group is to control the universal level of a group of input channels using a single fader. It may be possible that each channel requires a unique level setting. Controlling the sub-group with a single fader will affect the universal level of the bus, however each individual channel will maintain their proprietary setting. This concept is used extensively in mix-down sessions and during live performance engineering.

I am providing a diagram that I designed specifying this method. Notice the ALT 3-4 outputs feed a set of line inputs located on the same console. In this case any channel can be included in the sub-group by simply engaging a corresponding ALT 3-4 push-button. The line input channel fader controls the level of the entire group.