Mixing: achieving healthy levels with the help of VU?

Posted: Fri Jan 26, 2007 9:11 am

I'm looking to develop some sound techniques for setting relative levels within my mixes. I'm constantly looking at my master fader to make sure it's not clipping and I think this is due to poor practise in setting initial levels.
Once I get decent relative levels between instruments I look to my master fader to see how much headroom I have. Then, I'll either turn all the levels up so I'm using all available level or I'll put a peak limiter over the master fader and adjust until I'm using most of the level available.
I'm fairly inexperienced in the use of VUs, but they seem a better way to go in assessing the impact of a mix..
Can anyone offer tips on how to use a VU meter correctly and some general principles to stick by so i'm not constantly messing around with the level of my mix.
I've seen articles that suggest things like having your kick hitting about -10VU and then working backwards from there.. these types of ideas seem like they could help.
Where should I be setting OVU to? what should the peak level be in dBFS at 0VU?

Posted: Fri Jan 26, 2007 11:45 pm

luts, without trying to write a huge comprehensive book here, I'll try to be a little more succinct.

First off, master faders on both analog and digital consoles, including software's, can be calibrated slightly differently. In many consoles, the master faders should remain at the extreme top of its travel where the silkscreen might indicate 0, with numbers getting larger as the fader is turned down. Those numbers are decibel calibrations.

Whereas with other types of fader calibration, you might find + 10 at the extreme top travel. With 0 about a third of the way below that. Which is actually two thirds of the way up. If that Master fader is indicated that way, you would again positioned the fader at the "0" indication.

With that said and set, you are ready to begin mixing.

Regarding metering. These days, there are many popular ways to meter audio. The original audio meter was just an AC volt meter, calibrated in VOLUME UNITS or VU. Now these particular meters had special ballistics to them. They were designed to show average levels. Not peak levels. And so that is why you would get a recommendation of making sure your bass drum only made your VU meter indicate -10. That is because the VU meter typically could not indicate peaks that were generally 15 DB or more above what was indicated on a VU meter. So if the bass drums says -10 on a VU meter. You can bet your VU meter that the level may actually be 10 DB higher than the meter can actually indicate!

Back in Europe, where they had a little more sense, better television pictures, better equipment, they also had PPM or Peak Program Meters for their audio consoles. These meters had very different ballistics to the standard Volume Unit meter. They actually appeared quite "nervous" since they were indicating every peak.

Then we started getting neon/plasma displays, LED displays and VU meters with LED peak indicators! I personally like working with a VU meter with an LED peak indicator. But I don't complain when I have plasma displays that can actually be a combination of both peak and VU, simultaneously.

It's sort of like, do like gin or vodka martinis? With olives? Or onions? I'll drink them all but I prefer gin with 3 olives, please. Thank you.

So what does this have to do with mixing? I like shaken not stirred.

I really don't watch the meters when I start to mix. I watch the sound coming from my speakers. I see the image in my head and before me. Later, I'll start looking at the meters. Sometimes, I might have to adjust my Master fader if I'm hitting my summing bus too hard or, too little. But generally, I don't want to do that as it changes the gain staging, that might not be in the best interest of your audio. You might pick up more noise from the summing network? Or you might be overloading the summing network which doesn't sound cool either. So again, some of this is dependent upon whether you're Master fader starts with zero at the top of its travel or, with zero two thirds of the way up.

It's actually important not to watch the meters except when tracking. That's when you most want to watch the meters. Otherwise, once you mix, that audio can be manipulated for a proper level in the mastering process. That's provided, it's not ridiculously low or ridiculously over optimized, overblown, overloaded to begin with.

I hope this answers some of your questions? Because if it hasn't, you should think about selling vacuums.

I know everything about a vacuum
Ms.Kirby Hoover Electrolux

Posted: Sun Jan 28, 2007 1:57 am

On a slightly more simplistic note, your converters are most likely calibrated to -18 (= line level or 0dBVU). So, if you generally have levels that ride around -18dBFS (RMS) then you're right in the pocket with "normal."

You can always go a little soft - You should rarely go hot. Especially with a lot of "budget friendly" gear that has very little usable headroom.

It's VERY important to know that while digital gear is "Perfect, perfect, perfect, perfect, CLIP" analog gear is anything but. It's "Perfect (somewhere at or below 0dBVU), decent, slightly distorted, grainy, nasty, CLIP."

And it's (recording too hot) probably the single biggest cause of "Why do my mixes sound like crap?" beyond simply recording bad sounds.

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