Is this sound too quiet?

Mei Lewis · July 18, 2012

I'm fairly new to film making and mainly concentrate on the visual side. A few weeks ago I shot a short film where the sound was recorded separately by someone else, and I now need to use it in the edit. All the audio seems like it was recorded at too low a level, but I've not got enough experience to be sure.

I've been given the audio as mono .wav files. I don't know what the recording equipment was exactly, but it was a lower end recorder and boomed mic.

Above is a screengrab of one of the files in Adobe Audition. This particular track is a best case scenario in the sense that it should have been the easiest to record. It's a reading of a monologue that will be used as a voice over and was recorded in a quiet room, direct to the mic with no camera around. The peak level is about 20db below zero on the audition scale.

All the other audio I've received is similarly low-level, with only the slate clap and times when the mic has been physically knocked ever getting much above -20db on the Audition scale.

Is this normal?

Travis Gray · July 18, 2012

Probably kinda low untouched. I've worked with audio like that before, and you can always boost it.

The best way to tell is to listen to how it sits in the mix. Does it sound quiet? Then it's too quiet.

Keep an eye on levels too. I typically shoot for hitting and not going above 0db, sometimes I'll throw a limiter just underneath that so if something sneaks up it'll still be ok. But a lot of times music will hit those levels, maybe dialogue sits lower. It depends on the scene, and what's going on.

You could always run music through and make sure it's peaking at 0, and then set your speakers to a reasonable listening level and see how the dialogue sounds. That'd be my advice.

Adrian Sierkowski · July 18, 2012

I also find it's much more important that the audio is clean (little to no BG noise) -v- exceptionally loud recorded. Perhaps they were compensating recording lower in order to get some noise in the set below a certain level? I'm not an audio guy myself; but such things would make sense to me. Looking @ a waveform, as Travis mentions, is hard to tell if it's "Ok" or not.

Travis Gray · July 18, 2012

I also find it's much more important that the audio is clean (little to no BG noise) -v- exceptionally loud recorded. Perhaps they were compensating recording lower in order to get some noise in the set below a certain level? I'm not an audio guy myself; but such things would make sense to me. Looking @ a waveform, as Travis mentions, is hard to tell if it's "Ok" or not.

Yes, clean is also important. Very important. If you have something recorded quiet but the base level of noise is even slightly there, once boosted it's very noticeable.

This is going to depend on every link in the chain... source, microphone pattern, microphone, cable, external interference, recorder... but since you didn't record the audio, you have no control at this point.

If noise is bad, look for a noise reducer plugin. Apple Soundtrack allows you to set a noise print, grabbing a part with just noise and saying listen to this and get rid of it throughout the whole clip. Can be disastrous since it works with frequencies and if it's too noisy, it can pull out some useful information and the dialogue sounds like it's coming from underwater or something weird.

One of the things I do in this case is no noise reduction, maybe roll off the highs a bit to get rid of the hiss (it's important to know frequency characteristics of voices to know where to roll off and what you can play with), and then cut any audio not part of the dialogue, so right before and right after words, and long pauses. Then a slight envelope into those clips, and then lay down a room tone appropriate for the setting. Helps mask the noise in the dialogue a bit.

Mei Lewis · July 19, 2012

Probably kinda low untouched. I've worked with audio like that before, and you can always boost it.

The best way to tell is to listen to how it sits in the mix. Does it sound quiet? Then it's too quiet.

Keep an eye on levels too. I typically shoot for hitting and not going above 0db, sometimes I'll throw a limiter just underneath that so if something sneaks up it'll still be ok. But a lot of times music will hit those levels, maybe dialogue sits lower. It depends on the scene, and what's going on.

You could always run music through and make sure it's peaking at 0, and then set your speakers to a reasonable listening level and see how the dialogue sounds. That'd be my advice.

Thanks Travis. This is the original audio, I've not mixed it into the edit with other sounds yet. It's pretty quiet and is meant to get the viewer's attention so I'll probably have to boost it, but I really want to know _should_ the audio levels be higher. I got over 100 .wav files and they were all this quiet. My understanding is that they should get up much closer to 0db without clipping. Is that right?

Perhaps they were compensating recording lower in order to get some noise in the set below a certain level? I'm not an audio guy myself; but such things would make sense to me. Looking @ a waveform, as Travis mentions, is hard to tell if it's "Ok" or not.

On this recording they were in a quiet interior with no one talking and little other sound so I don;t think it was recorded low to avoid noise. The recordist did mention that on the sections outside he was recording low because of wind noise, with the idea to boost the signal in post - but that makes no sense to me, if I boost the voices I'll also boost the wind noise so I'm back to where I started, with more noticeable self-noise and perhaps aliasing.

Maybe there's some advantage to not clipping on the wind noise, but I don;t see that either. If the wind noise is loud enough to clip then it will surely mask the voices at that instant too?

Yes, clean is also important. Very important. If you have something recorded quiet but the base level of noise is even slightly there, once boosted it's very noticeable.

This is going to depend on every link in the chain... source, microphone pattern, microphone, cable, external interference, recorder... but since you didn't record the audio, you have no control at this point.

If noise is bad, look for a noise reducer plugin. Apple Soundtrack allows you to set a noise print, grabbing a part with just noise and saying listen to this and get rid of it throughout the whole clip. Can be disastrous since it works with frequencies and if it's too noisy, it can pull out some useful information and the dialogue sounds like it's coming from underwater or something weird.

One of the things I do in this case is no noise reduction, maybe roll off the highs a bit to get rid of the hiss (it's important to know frequency characteristics of voices to know where to roll off and what you can play with), and then cut any audio not part of the dialogue, so right before and right after words, and long pauses. Then a slight envelope into those clips, and then lay down a room tone appropriate for the setting. Helps mask the noise in the dialogue a bit.

Thanks Travis. I think this clip is okay to use with boosting the level and maybe some noise reduction and some other of your advice. What I really want to know is should I have to do this? All the 100+ sound files I got are like this and I could do it to them all I suppose but is this normal?

Travis Gray · July 19, 2012

Probably the easiest thing to do will be to stick them all in the same track, if they're all getting the same treatment, and then add the boosts/eq to that track.

My last audio issue I was dealing with, boosting low pickup, was a mix between fine audio, and then the lav didn't grab some of the other lines like I thought it would. I just took all the quieter spots and cut them down to another track. Kicked up the fader as much as I could, and added a gain plugin on it (you could add gain with an EQ plug in as well, they usually have gain in and gain out.

I could go into a whole thing about compression and RMS and peak values, but I think you'll be ok with getting the peaks to register at 0 or just under to get your starting point, and then listen to it in the rest of the mix to see how it sounds.

If you do bump it up to 0 and it's too noisy, play with a room tone in the background and cutting out silent parts, or EQ, or bring it down lower and see if the dialogue is still intelligible through the program.

Then in the future, get the sound guy to record a little bit better of a signal. Mics closer to the actors, in the right position, cutting out extraneous noises, etc will all help. When I'm dialing in audio, I always have the talent deliver a line that'll be the loudest in the scene and set from there. I'm not usually running a compressor during recording, so I want to make sure my loudest part is going to be ok. I'd rather have some noise than clipping.

Vadim Joy · March 17, 2014

As others said, make sure to set camera to -20dB and Mixer/Recorder to 0dB. This will give you most of the audio. Again, of course it depends on the situation you're at. But most of the times it works for me.

When I edit I like to keep my dialogue levels around -3dB. Again depends on the scene.