Matching Clip Audio In iMovie

Often when working with a video we end up with video that has a different loudness for the sound in different clips. What I mean by that is that in one clip the voice is nice and crisp and the right volume and in the next it's kind of low or maybe even too loud. Then when you edit these clips together it doesn't sound right. You jump from one clip to the other and suddenly the volume is less and you can't hear what the person is saying. There are tools to deal with this in iMovie. So let me show you an example.

I'm going to drag two clips, just two files that I recorded using QuickTime Player, and they both look to be about the same. But what I did is in this first clip here I kept my microphone where it normally is, which is right here, and in the second clip I pushed the microphone away like you may have accidentally done when recording video and you only realize afterwards that the microphone was a little too far away. So you can see here the volume, this soundwave here at the bottom, it's nice and robust here but here it's kind of weak. You can definitely hear it if I play the clips. So you can see how I'm quieter in the second clip and even worse you could hear more of the room. There's a little bit of an echo. So I'm going to do two adjustments to fix this.

The first adjustment I'm going to do is adjusting the loudness. Now you select a clip, I'll select this first one,  and go up here and I'm going to click on Volume. There's an Auto button for adjusting loudness. Now this is the clip that's fine. But I still want to go and hit the Auto button to adjust it. You can see it's going to raise that a little bit. So it thought it was a little bit too low. So now it's kind of at this neutral level. So now when I go and select the second clip and I hit Auto it's going to increase that and hopefully it will match a little bit better.

I could've, and I'm going to Undo twice here, I could have selected both of these and hit Auto and it will do both of those. That's useful of course if you have like seventeen clips and you don't want to do it for each individual one. Now it's going to sound a little bit better. So what I've done here is I've boosted my voice to match the voice here but I hear a lot of that background noise. So there's another adjustment I'm going to make.

If I go over here to the Noise Reduction and Equalizer settings there's a Reduce Background Noise option. So I'm  going to turn that on. But I'm only going to do it for the second clip here. So Reduce Background Noise. I have a setting here for, you know, how much to reduce it. I'm going to leave it at the Default here and see how that sounds. So it sounds better. It's not going to be perfect because there was a problem with the microphone. You're not going to be able to magically fix that. The idea is to get it to play better.

Now for further adjustment you can certainly do that. You can go here into the Volume and you can adjust the volume with this slider here and you can see it moves that line there. You can also click and drag and move that line manually to get it just right. So you can kind of adjust this until you get something that sounds right to you. So it's probably somewhere in-between those two. I'll have to play around with it a little bit more.

Now what if the sound varies inside of a clip. So one thing you can do here is with this line, instead of dragging the entire line, I can Option Click to create some dots. So I'm going to create a set of dots here. I'll create four dots and now I can click and drag this section here. You can see I can lower it. So I can move these back and forth and create a section here that I think would fit this. I can lower it. I can raise it. So you can do that within a clip. Let me Undo that here. 

You can also split a clip. So I can position it here. Let's say before this the volume is fine and after it I want to increase it. So I can actually go in and use Command B to split it. Now I can leave that fine and I can lower or raise this one. So splitting clips kind of does an abrupt change of volume right there whereas using the Option Click to adjust the sound curve, that's what that line is called, will help you do maybe a gradual lowering or raising if you want to play around with that.