Thursday, 12 July 2012

Mixing 101 - Line Check - Part 1 of Many


This week we start a new series of posts that will concentrate on mixing desk fundamentals.
I'll be using the Allen and Heath Zed series of desks as a reference for this series, mainly because they are probably the best quality small format analog mixer on the market right now and also because they have all of the most important functions we will be talking about in this series and none of the unimportant ones that often clutter desks up.

Lets say you have just un-wrapped a brand new mixing desk and are about to use it for the very first time.
Where do you start?
Its tempting to just dive in and plug stuff in, and rather than be a killjoy who tells you to read the manual from A to Z whilst 'familiarising yourself with your new mixing desk's layout", I'm actually going to suggest its not actually such a bad idea.

But here are a few suggestions to make the process less painful..
Before you plug in anything, zero all the faders, slide them all the way down to nothing so that no audio signals can come out of the desk.
Next find the gain or trim knobs (usually right at the top of each channel strip) and spin them anti-clockwise all the way down to nothing.

The rest of the channel strip knobs also need to be set to zero, where zero is will depend on what the knobs function is. It is important NOT to set them all fully anti-clockwise.

The following knobs are zero'd in the full anti-clockwise position:
- Anything with AUX written on it
- FX sends

The following knobs are zero'd when in the 12 oclock position (pointing straight up):
- EQ  (usually labeled HF, HM, LF etc)
- PAN

If your desk has a phantom power switch (usually labeled with '48v') on each channel, make sure it is off for now.

Now you are ready to begin, I'll take you through the process of getting ready to use your desk. You go through this same process every time you use it, for every gig, no matter how big or small. The same process should be used when playing on a Thursday night at the Cossie Club or at an 80,000 seat stadium show.

Step 1 - With all the faders and knobs zero'd, plug in all your instruments into the channels you want. Set them up in a layout that is easy and quick to access and try and use the same layout everytime you play. The 'unwritten' soundguy standard is to put drums first, bass, then guitars, then other instruments and vocals last. Plug your PA or speakers into the desk outputs.

Step 2 - Line check. This step is just to make sure that everything is plugged into the right channels. One person taps each mic or makes a noise on the line while the other person checks the desk. Most desks have a PFL button that helps with this process. While a helper taps the kick drum mic, press the kick drum PFL button on the desk and slowly turn up the gain / trim knob until you start to see the signal on the signal meter. If you don't see anything, check the microphone does not need phantom power (turn on the phantom button if needed). If there is still nothing, you have something plugged incorrectly, or you have a faulty cable or microphone. Get this sorted before moving on. Work your way through all of the rest of the channels until everything is where it should be.
Note: You haven't turned up any faders yet, and no sound has come out of the speakers.

Step 3 - Setting the gain. This is the most important step, in fact it is so important I am going to dedicate an entire post to it next week. Getting the gain right is the single most important thing you can do to ensure whatever you mix sounds great so it is worth spending a bit of time understanding what this misunderstood little red knob actuall does.