Friday, March 9, 2012

Guest: Karl Maciag - The Mix (Part 1)

 We are blessed to receive our second installment from one handsome devil named Karl Maciag.  If you missed his first post it's HERE.
Devilicus Handsomicus
My first entry dealt with microphones, microphone placement, and thinking about why you choose the mics you do. Following the flow, we have the mics hooked up to mic cables, which probably go to some sort of snake, and onto the console. I don’t think an entire blog of cabling is appropriate, although it is important. I will say this about cabling though. KEEP YOUR STAGE NEAT!!! There is nothing I hate more than a 40’x40’ stage of spaghetti. As an engineer, it makes me think you don’t care, you don’t plan, and you might not know what you’re doing. As a musician, it makes me think you want me to trip and break my neck. Use subsnakes. Coil excess cable at the mic, not at the snake head. Anyone who has worked with me knows I don’t get mad and yell too much on stage. I do yell though when you’re working for me, and the stage is a mess. It’s a testament to your professionalism. Take the time, do it right.

OK, rant off! After the perfectly chosen and placed mics are patched neatly into the snake, they run off to the console. I want to take a look at typical console sections, and how I look at them. Some of the stuff I will mention is probably some beginner type stuff, but it’s always good to refresh.

So the console is a large collection of different devices, working together to provide you with the ability to mix a number of microphones into typically a stereo, or LCR mix. Think about the different console sections as separate devices, and how they effect each other down the line.

First you’re going to use a preamp. The preamp takes the lower voltage mic level signal, and amplifies it to a more usable line level signal. Line level is equal to 0dB, in the analog world. In the digital world, it can be -18dB, or even -12dB, or some digital consoles convert the information to represent an analog scale, so the
digital level will display as 0dB. Confused? This brings up a very important point. Know the console you are working on. They behave differently. If you’re a visiting engineer, find out before hand what console you will be working on, and get the manual online. Midas consoles, like the Heritage series, have a gain stage much hotter than other consoles. If you gainstage to 0dB, your mix is going to be very quiet. The happy place on those desks are closer to +9dB. Yamaha PM consoles are the

opposite, on the input , aim for the -6dB light. If you hit the 0dB light, your mix is going to shred faces off. Those preamps do not like being run hot. Soundcraft and Allen Heath like 0dB, but I do take liberties sometimes with running them a little hotter. Digital console? Don’t clip those preamps! Very nasty sound when that happens. I guess the point is, when you can, experiment with what the preamp can do, and where you think the inputs sound better. Start at 0, and go from there.

Also in the preamp section, you might find a high pass (low cut) filter. Do not neglect these, use them on everything except for drum/bass/keyboard channels that need the low frequencies. You’ll save a bunch of grief dealing with your other inputs. For fun sometime, during soundcheck, take out the high pass filter on your lead vocal channel. You’ll be grateful you have that little button to take out the mucky muck.

Moving on from the preamp, there should be an insert where you can insert outboard processing into the channel right after the preamp. I’m not going to talk about insert processing in this post, but be aware of the inserts, and that it can disrupt your signal if they are patched wrong. When I say disrupt, I mean, no sound getting through….

Next we will assume the EQ section is next. This is where we shape the tone of the sound. I’m going to assume that you know how the EQ sections works, God knows I don’t want to explain that. I will explain my approach to how I typically use EQ. In a word – “sparingly”. I very rarely add frequencies to an input. Maybe a little 50Hz for a kick drum, maybe some 3Khz for attack on the toms. Not 12dB, just a bit. If your mic is placed properly, you shouldn’t need it. I find that I subtract frequencies from inputs more than anything. Toms typically need some love to get rid of ugly overtones if tuning is off. Typically with vocals, there tends to be some frequencies that stick out and sound ugly. Some voice/mic combos don’t work well. It could be a muddy sound, so you’ll subtract low-mids. It could be a shrill/piercing sound, so you’ll subtract upper mids. Take out just enough to alleviate the problem. Too much upper mid reduction could loose annunciation in the voice and definition. Too much low mid reduction, and the voice will sound too thin, and approach a “telephone” type sound. I almost never add any high frequencies (above 8Khz) to vocal channels. There’s nothing there for them. You’re boosting stage bleed, cymbals etc that the mic is capturing. Maybe in the studio you can add that for “air”, but live, you’re just going to be boosting noise for the most part.

Speaking of boosting and cutting…this goes in line of how the console sections effect each other. Boosting and cutting frequencies means you are adding and subtracting gain to your input. If you set your preamp to 0dB, and then hack -15dB on your low shelf, and another -10dB somewhere in the mid range, that input is going to be much quieter than you hoped. It’s just something to keep in mind when you’re making adjustments.

Another key with EQ is understanding the frequency ranges that your musical instruments reside in. Musical notes and octaves correspond with frequencies in the audio spectrum. So if you have drums, bass, electric guitar, organ/Rhodes, and piano, there’s a lot of notes going on, and a lot of them are in the same octave ranges. You can use EQ to subtract frequencies from one input, so that another input can peek through the mix. Give instruments their space in the audio spectrum.

Is that enough on EQ? next, the auxillary section.

Tune in tomorrow for the second half of this post.

Karl also writes his own blog at Karl's Empty Space 

1 comment:

  1. You learn something every day. I've been mixing on Soundcrafts and Allens for a long time and have always tried to hit 0 dB. Mixing on a few Yamahas I've definitely hit the headroom issue that they all seem to have. And now days I mix on a Midas and she doesn't mind it all if you shoot for +9 and even tickle the red lights a bit.

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