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Lesson Info

Addressing Common Audio Issues

Some common audio issues. So, ground loops. Ground loops are when in a situation where I have all kinds of things hooked up to this mixer, sometimes they can compete for grounding. The devices don't know and it causes this humming, buzzing sound. It's terrible, you don't want it. That's a really hard one to get out in post production, it's pretty hard to remove. So we wanna make sure that we catch it by monitoring our audio and then we find out where it's at and get rid of it. So it can be internal to the gear. The wall power in our house is not really set up for audio production so it could be coming from your wall. If it is, once you isolate and you're like, "I plug this in and that's when I get the sound," pull it out of that plug and put it in the next one. It might be on a different circuit and that one might not have a ground loop and might be fine. So it might be just plugging it into a different wall outlet. I have a video here. This is what a ground loop sounds like because I'...

m telling you ground loop but we should hear these things so we can identify them. This will help us to know what we're looking for. Hold on to your seats, this is gonna hurt. I'm just kidding. This is louder than you'd normally hear it and then it'll go blank and then it'll play the volume that you would probably normally hear it at. Anyways, so let's take a listen. (loud buzzing) (low buzzing) That's the level you're probably gonna hear it at and that can slip past you and especially if you don't have headphones on, you're not gonna get it until, "Oh, I'm gonna put headphones on and start my editing. "What's that sound?" So make sure you're monitoring. That's the level you're most likely to hear it at but that's what it sounds like. So, we wanna be able to identify those, know what we're listening for instead of me just saying, "Hey, get rid of your ground loop." Another one. I've talked a lot about clipping. Sometimes people call it peaking. Actually I have a video and I say peaking, it should just be called clipping but same thing. It's clipping off the top. When you hit that zero in digital, it's clipping off the top, it says we got no more room to record this and it cuts it off and it sounds terrible. That's a gain staging issue when we set up our gain. You got it too loud, you're too close to the top, you're not around minus 12 dB when it's the loudest. Your loudest parts of your speech should be the minus 12, not on average. So adjust your gain. If you have a limiter, use those. We talked about limiters. Use the limiter. Your technique, back to my technique, this is part of learning, avoiding the tongue clicks but if I'm gonna laugh really loud or I'm gonna have a cussing fit on the microphone, "Hey you, blah, blah," do it off the mic, alright? Turn away and you'll get used to this. In the beginning you'll just burst out laughing and it'll peak the audio. You'll learn some of my technique, you'll learn to back off. Singers, you've seen them work the microphone and they're like getting into it. That's what they're doing, they're basically doing gain control in real time. And your guest. Your guest is always gonna get louder when you actually start. So you're gonna set up their levels and you're gonna say, "Hey, what did you have for breakfast this morning?" That's what they always say to say, it's terrible. All my guests say, "Yeah, I don't do breakfast." I'm like, "Look, I just need you to talk, dude. What'd you have for lunch?" "I don't know." Just talk. (audience laughing) So they talk and you set their level and then you actually start getting into the interview and all of a sudden they get loud and excited, I'm like, "What's going on? "Why did your voice change?" So maybe your first few questions aren't the most important questions, they're questions you don't even care what the answers to. As they're talking and answering questions in real time, you're adjusting their level for that minus 12. So just some things to be aware of. So this here is, we'll get there, this is peaking and clipping. Again, just clipping. You can see the wave forms, they're cut off. My audio is damaged, it's gone, here's what it sounds like. I've turned it down but this is what the distortion sounds like. We're talking into the Shure SM58 with normal audio levels and now we are distorting the levels so you can hear the peaking and the distortion, it sounds terrible. And this is back to normal, sounds great. Sounds terrible. So that's what clipping sounds like. So you'll know it when you hear it. Recording too low. I talked about your voice being above the noise floor, if it's closer, a gain staging issue again. Work on your gain, get it near that minus 12 on peaks, playing in that 18 and 15 range. Too low is probably better than too hot because clipping it's gone, low we're just gonna introduce a little bit noise when we bring it up but we can clean that up if we have to. At least you didn't ruin the audio. This is what happens when you record too low, we're close to the noise floor and then in post production you gotta bring it up. Okay, recording levels that are too low. So when I have to bring this up in post production, the result is this. (soft static) Just a lot of noise, which we do not want. So a little hard to hear here in the studio but trust me, there's more noise than we want. If we'd brought that file up and we record it properly, you wouldn't hear any of that hiss. Buzz and hum. This is nasty, there's a lot of cables crossing over other cables here. Ideally, especially power cables, you don't wanna run your microphone cables over power cables, it can pick up interference. Being close to the computer screen. This microphone, this USB microphone is not well shielded, it's one of the things that's not gonna make it professional the way the XLR microphones are better shielded against interference. Back away from your computer screen. This picks up an amazing amount of noise from a computer screen. And decouple the stand, I talked about that buzz and hum can come up through the stand. Get it off the table. If it's coming through your boom arm, mount that boom arm somewhere else. They have mic stands that go on the floor and then a boom arm comes out really cheap and it's decoupled from the table. So this is, let's see, buzz and hum. Okay, I talked about the rejection capabilities of a professional mic, XLR microphone. This SM58, built really well. It does a better job of rejecting problems in your atmosphere than say this one does. And this is just an example of that. Alright, this is the Q2U when I set it on my desk. (high pitched buzzing) This is the SM58 when I set it on the desk. So the Q2U just much more prone to interference as you would expect based on price and build quality. That said, that's when I set it on the desk. It's not a problem when it's in the mic stand so just be aware, different mics can respond differently but if you hear those sounds, move the mic. Pops, clicks, dropouts, all these things that can happen in your audio, that is trying different audio cables. Your audio cable could be bad. Try a different XLR cable, try a different USB cable. Make sure the connections are tight. That's why I like XLR, they lock in, it's more secure. USB cable, just make sure it's tight, it's not loose. Try another cable. Buffer size. We set buffer size in our software. If it's too low because you're trying to monitor that audio through the software without getting a delay, your computer can't keep up and it'll cause dropouts and stuff like that. So if you're hearing that, increase that buffer size, way to fix that. Mouth noises. They say avoid coffee and milk before you record. I'm podcasting so I want a beer. It's not the best decision. (audience laughing) It's probably gonna make me, it's not the best decision. Do what you want, you gotta have fun. But have your water. They say green apples can help with the click sounds in your mouth. Whatever, if you have mouth sounds you can find a lot of information on the web. People have all kinds of recipes for preventing mouth sounds. Honey and tea and all these things but just be aware of it. And balancing your levels. Again, we talked about how your guest and person, they're probably gonna be at a different level than you are, try to match those. So my level is pretty even in the audio meters when I talk, it's around the same as them. This especially if you have like a mix channel. If you're sending both of yourselves to a mixed stereo signal, in post production that's gonna be a real pain to adjust them to get them at the same level. Normally we wanna do multi-channel recording, recorders let us do that, where each of us on our own track and then it's super easy to fix but if they're too low and you're just right, you've got a gain staging issue. They're too low so they're gonna have worse audio than you are. So we wanna get them balanced so set the gain right, do it for both people, and it helps you to see that you're going in about the same level they are, that minus 12 on peaks. Mouth noises we talked about, the tongue clicks, lip smacks, mic technique, learn your habits. If you smack your lips, click your tongue, just listen to what you do on the microphone. Record yourself and play it back. You'll hate your own voice because we all do, you'll get used to it. I find so many people doing the podcast and they're like, "I just can't listen to my own voice." Have someone else edit your own podcast. I always say we are the absolute worst person to work on our own podcast because you're gonna sit there and listen to yourself and you're gonna be like, "I hate the way it sounds," you're gonna increase the bass because I want a warm voice, I want the radio voice. You'll get used to your voice. Everyone sounds wonderful. That's what's cool about podcasting, it's not the radio voice. You're not trying to be someone else, be yourself. Inconsistent levels. If you are going off mic, you're gonna have, that level's gonna go up and down. You're EQing in real time. Use a pop filter to keep you on top of the microphone, use headphones so you can hear as the audio comes in and out. For you and your guest. The proximity effect, again we talked about being super close to it. Back off the mic. Plosives, take care of those. If you need to test your plosives, we've got, sorry, I'm not keeping up. I don't even wanna say all that 'cause I'm mess, Peter Piper picked big bushels. Do that in the microphone, see how it comes out. That will give you plosives. Same things with sibiblance. Sally, she's selling some shoes for seven cents. That'll test your sibilance.