Richard BF

This was originally just a muck around with Singleton, our company mascot, and to address some of the queries I’ve had about our one way mirror. But it turned into having some fun with Final Cut Pro 3, trying yet again to see what it can do with audio. So watch the video first, then come back and read the rest of this post.

Watched it yet?

So the Singleton voice was done using the Voice Over function of FCP, straight into the Mac with a microphone. The problem though is that it sounds like someone talking into a microphone.

When Singleton first speaks, inside, I’ve put a small room reverb on the voice to not only match the room size, but more importantly to match my voice but slightly muffled, because he’s behind me. He’s also slightly off to the right side, so we pan it to about 29% to the right. You don’t want it all the way, or it will sound outside of the actual image, and just inside the frame is going to be around the 80-90% mark.

Next, we’re outside, and Singleton says it’s cold. The camera moves a little, so the location of his voice varies throughout the shot. If you fixed the sound at one location in the stereo image, it would sound strange to most people, because on TV and film, sounds are always located exactly where they came from. Most people don’t realise how much effort has gone into it.

The nice thing about FCP, is you can cue to the start of where he talks, edit the audio, mark a key frame and pan the audio to where Singleton currently is in the shot. Then keep watching until he’s just left of centre, and edit that, drop in another keyframe and pan it to about 15% left. By marking just these two points, FCP will mixdown the gradual pan from right to left for you. Finally the shot moves back to the left and then centres as I go inside and shut the door. All up there’s four key frames to mark, setting the pan at each point. Mix it down and play it back, and you’ll hear Singleton’s voice move around with him on the screen.

The next problem is the reverb for outside. You can here my voice is pretty echoy, because we’re inside a concrete depression that just bounces sound all around. To match Singleton’s voice, I can’t use any of the room reverbs, because they’re designed for reflections off soft material like paint and wood. Instead I use what’s called a Fat Plate reverb. Before digital, they used a big metal plate in the studio, with a speaker at one end and a microphone at the other. When you know it’s a metal plate, you can sort of hear it, but if you don’t, it sounds like a tunnel or echoes off concrete. Anyway, the outside gets the fat plate treatment and it sounds a little like Singleton’s actually there. Unfortunately FCP’s reverb isn’t very tunable, so I also took out some of the brightness, and that’s the best I could get it.

Now, when I close the door, he’s supposed to sound muffled, so for that I used a low pass filter, it let’s the low rumbling bass frequencies through, which can travel through glass, but removes the higher bright frequencies, which in a real sound would bounce off the door and not go through. I set this at 1Khz, and it does the job. The point here is to make it sound like the door is muffling the sound. In film they know what’s called the absorption coefficient of this type of glass, and can match it exactly.

Finally, the rest is all fixed location, so we go back to the Fat Plate reverb. Technically he’s outside the door, so we should have the muffle in there as well, but then the voice would be pretty bad and hard to hear, so we add a little of the low pass filter, but not as much as before, and gradually make it clearer so the audience doesn’t realise it’s not there anymore. So around 2KHz for the first time oustide, and 3Khz for the rest. That’s fine, films do this a lot, add the effect for the cross over (closing the door muffles), cut the shot and come back without the muffle. Most people are trained not to pick it up, and could arguably be that the focus is now on the oustide. Coincidentally, it’s the same trick you use with theatre lighting.

Now watch it again, and all the above will be obvious to you, and quite noticable. You can do the same in the cinema if you sit in the middle of the surround, and on low budget films you can pick out the edits and badly mixed in effects.

So, did you find this interesting? Let me know what you think.