From the course: Video Production and Post Tips

Removing buzz during production

From the course: Video Production and Post Tips

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Removing buzz during production

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- Now Rich, when it comes to reducing buzz or hum out there in the field, there's a lot of, you know, surprisingly simple things one can do to make sure that this problem is remedied in the field or on set, rather than waiting to figure it out and fix it when you get back to your studio. - Well, and let's start with a simple one. First off, if you don't hear it until you get back, that's a problem. I've been on set and people are just looking at the VU meters. Truth be told, you need some over the ear earphones. You're going to want to put those on, and make sure that you can actually hear the problem. Listening on earbuds isn't going to cut it. Just looking at the VU meter on the camera isn't going to tell you that there's buzz. But it's a very good idea to make sure, even if you're a one man band or a one person crew, to occasionally check. Rob, I think this is the biggest problem. - Yup. - People trying to do too much on set. - Hands down. And if you're on a, you know, multi person shoot, the person monitoring that audio should also be empowered to just say hey guys let's stop. You know, there's plenty of times where you have, you know, clients around, or maybe an important director or producer. That's no substitute for capturing bad audio. That person monitoring needs to have the ability to say nope, nope, stop. We need to figure it out. - Yeah and you can do it tastefully on set. Another problem that's going to happen is I see people, particularly if they're using DSLR cameras, using single wire type solutions for the microphone, particularly things like mini plug. - Yeah. - And really if you can, you want to step up to shielded XLR cable. What's the advantage of XLR here, Rob? - Well, we have a balanced audio connection. So, balanced audio connections are going to typically be found in either an XLR connection like you see here, right, where you have three pins. One of those pins is a ground. Or you're going to see it in the TRS quarter inch connection. Tip, ring, sleeve, so it looks like a guitar plug, but it is a balanced connection as well. I mean, you're right. You know, kind of a standard eighth mini jack is going to be unbalanced audio, and by definition the balanced audio is less prone to getting interference. But there's another point that you make there that I think is really important, and that is-- - Yeah, it's got a thick rubber sleeping bag on it. - Well that is the actual, you know, one of the things that can protect your cables is the shielding, and that shielding does a couple things. It first kind of protects it from kinks and bends, so it doesn't actually break. But it also can kind of shield it from, you know, electromagnetic interference that you might find on a set with a lot of electronics. - Well, speaking of that, you know, a lot of times you have power running all over the set. It's the same reason to have a thickly shielded stinger like we do here. But if these two cables get too close together sometimes that creates electrical buzz. - Now Rich, I know this comes as no surprise to you, but for our viewers out there, I suffer a little bit from OCD right? And when it comes to cables, I often see people, you know, kind of behind the racks or hanging off the camera, with things kind of like all bundled up like this in a pile. - Oh, that's bad. - And then you know they're running this connection, and then they go, why do I have buzz in my audio? And you're right. You can usually run cables in parallel to each other, but if they get too close, sometimes they can, they can get some buzz there. - And particularly if they cross each other. I see a lot of times on set someone's connected on a mic. The subject moves, the camera moves, all of a sudden you've got cables crossing each other. - Especially with power cables. If you do need to cross, it's a better idea not to cross kind of by overlapping, but to make a hard 90 degree angle to the power cable, to make that cross, cause that's going to reduce the potential for having a buzz or hum in your audio. - Yeah, so if this has to cross, make sure it does that at a straight 90 degrees. - Yup. - Or better yet, don't cross at all. Sometimes, we'll just take things over. Simply put a riser over there, or a pad, or run one of these through an apple box, and one over the apple box. - Yup, you know, another good device to have on hand is a ground loop isolator. A ground loop isolator is going to reduce, as its name says, potential ground loops. You know what ground loops are, Rich? - I am assuming that they're the cycling sound. - Right, so depending on how a building or a location is actually wired, the power itself might be causing some interference. - Yeah. - So a ground loop isolator simply plugs in to the actual power outlet, has a little transformer inside, and greatly reduces the potential of hum, and I carry a few of those with me as well, cause sometimes no matter how you isolate the cables, simply plugging in to a nearby outlet might be the source of the hum itself. - Yeah, and we also sometimes get interference here. We have a radio station near the studio, so it becomes important sometimes to move the cables, or be careful if they're touching something, like say, a metal leg on a piece of equipment that becomes a giant antenna. Speaking of antennas, wireless mics, there's something you can do there, too. - Yeah, absolutely. That, the thing about the radio station reminded me about this is that wireless lavs are a great choice for just having that flexibility of being unencumbered by wires, but sometimes you're going to get interference. Wireless mics are usually going to come in VHF or UHF. So, very high frequency or ultra high frequency. That ultra high frequency is less prone to having some interference simply because there's not as many devices on that part of the spectrum. But one thing you can do on a lot of wireless packs, like this one included, is simply change the channel that your receiver and the transmitter are on. Remember, they have to be on the same channel to communicate. But often times you might, hey, channel nine is noisy for whatever reason. Changing to channel 10, oops, it's gone. That might also fix a lot of your problems. - So as you see here, it really just comes down to paying attention. Making sure that you're using headphones to spot the potential problem, making sure that the audio engineer or person in charge of audio recording has permission to either interrupt the take or communicate with others on set, because you don't want to let these issues go, and then working through the problems. Check your cables. Check your power connections. Check the channels that you're on. Rob, this is great advice. Very practical, easy to put through, but still, no matter what we do, sometimes problem audio sneaks through. So when we come back, we're going to take a look at one possible way of fixing it using software.

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