Broadcast standard.

[Eddie Rex]

Previously i have never had my films broadcast on television before and now for the first time i am getting some interest shown from Propeller TV.

However they sent me an email that the audio was "up and down" and needed stabilising, so using premiere pro normalised the sound until i thought it sounded ok...

Do you think this will be sufficient? Or is there something more i could of done?

 

[knightly]

is this the audio on TPW?

 

[Eddie Rex]

Yes

 

[clive]

normalised the sound until i thought it sounded ok.

That's where you're going wrong - you can't set levels by ear there are too many variables.

So, the only way to do it is watch your sound meter all the way though the mix.

Your levels should stay in and around the -12db range

 

[knightly]

If this is the same cut of the movie that you added the sound fx to, I would recommend going through and listening with a critical ear to make sure the sound effects don't jump out quite so much, As for the dialog, I concur with clive...match it with the meters...You can export the audio and use audacity (free) to help with that. Make sure just to change levels, not the length of anything as that will screw up the synch with your video.

 

[DirectorX]

I'm not an audio guys but I've done some basic audio editing/mixing.

Using your ear to adjust the levels is something you do in the early stages of the mix. There you adjust how you percieve the different levels of your audio elements should mix (volume of dialog, music, sfx, etc). Dialog is most critical. Also make sure you are monitoring (listening) to your audio in a similar environment as your audience (ie. don't use headphones if your viewers will be watching this on their tv). When you are done with the mix, the most important thing is the levels! You must watch the levels! -12db is a good place to be at. You can go higher. Digital audio is clipped (harshly) at 0db. You want to avoid clipping at all costs! The most foolproof method for that is to playback your whole mix and watch the audio levels. Final Cut will show clipping by displaying two red dots above the audio levels. Soundtrack Pro (part of Final Cut studio) goes a step further and even tells you by how much clipping has occured. I don't know how Premiere is. If your audio has clipping, adjust the master volume slider on the mixer to compensate for that (or for that particular audio track). Make sure you are using keyframes so you are no modifying the master volume for other parts of the mix that may be fine. Having said that, since you are going to output for television, it's also a good idea to appy a Compressor (depending on how dynamic your mix is). TV sets don't have a great frequency range.

Another somewhat important note:
If your audio mix is long, make sure you take breaks when mixing. As you work with audio and listen to your mix over and over, your ears tend to become less "responsive" and you may begin to percieve your audio levels as being too low. As a result, as you move along the timeline, you may tend to jack up the levels more and more...

Hope that helps a little. Again though, avoid all clipping if you want the audio to be broadcast safe.

 

[clive]

Using your ear to adjust the levels is something you do in the early stages of the mix.

I understand what you're saying, but have to disagree.

It's the other way round. Meters first -- Ears last.

When the audio goes in you set the clip level against the meters -- the dialogue at about -12db.
Sfx below that about -18 to -24
Music at about the same.

This gives you a rough, but consistent sound level of between -12 db and -9db

Then you decide where the balance between those elements need to change - this is a combination of listening and maths

So, if you decide to up the music to -12, then something else needs to come back by an equal amount.

That's when in FCP you set audio keyframes to manipulate the movement of the levels.

Your final mix is where you listen to the balance between the elements -- and is the part of the mix where listening and having good ears is important.

Truth is that the vast majority of people don't have "good ears" and can't accurately judge the mix -- that's why a sound engineer with "good ears" is worth their weight in gold.

The reason for this is that there are too many element in volved in creating the sound for listening to be effective -- the recorded source levels -- the level of the computer's output -- then the amplification level and finally the speakers.

If you mix by ear, your're only mixing for that set up -- as it is on that day -- and even ambient temperature changes or furniture placement will change the output levels.

 

[Eddie Rex]

Thank you all for your guidance.

Having just reviewed TPW the audio varies between 0.0 db and 18.8 db and probably is still not the broadcast standard.

When you mention around 12 db, do you think between 8 db and 14 db is acceptable?

 

[DirectorX]

Listen to Clive, he clearly knows more about audio than I do (although that does not make you very special, Clive )

[I wrote that post at 2am, when abviously I should have gone to sleep instead!]

Luckely I have my "audio girl" to whom I send my edits. She does the mixing in Protools. I do none of that so I'll stop talking now!

You may be ok between -8db and -14 (pending Clive's approval). Are you refering to your dialog or overall mix?

 

[clive]

Luckely I have my "audio girl" to whom I send my edits. She does the mixing in Protools.

Absolutely the best way to go.

Listen to Clive, he clearly knows more about audio than I do (although that does not make you very special, Clive )

I did work in studios for eleven years -- but as a producer not an engineer.

First time I mixed my own audio -- made exaclty the "by ears" mistake -- then had to sit and listen to it in a theatre.
ALMOST DIED OF SHAME!
Then went and bought a book on FCP -- so I'm not really bucking for Audio Guru

Having just reviewed TPW the audio varies between 0.0 db and 18.8 db and probably is still not the broadcast standard.

When you mention around 12 db, do you think between 8 db and 14 db is acceptable?

The first set of figures -- absolutely not.

On the second set -- impossible to say -- depends on the dynamic range of the piece.

I'd aim to have 95% of the film between -10bd and -14 db -- with occassional fluctuations outside those parameters.

 

[mdifilm]

for audio, I usually do is lay the original audio track there and cut it into the clip (finished) I like, then I export the audio to Sound Forge to clean it up (getting rid of background noise, normalize, adjust level), save it and bring it back to premiere (note, this is how I work, doesn't mean it's the ABSOLUTE way, however, I like what the result and had no problem for broadcast).

Once it is lined up, I adjust with the meters and such, then I export to DVD and play it in 3 different sets, one is a regular stereo tv, one is a 5.1 surround sound, and portable system, and the job is to listen to it without watching, this gives me a better understanding what area goes wrong.

For me, I rather have it right than have it wrong so I take a lot of pride and care on audio, obviously, if the background noise is too BAD, I just *ahem* lay a music track over...

Johnny

 

[Eddie Rex]

Thank you all for your guidance again!

Now having edited TPW the audio now varies between -10.4 and -12.9 db which does sound so much more professional. I shall burn another dvd for sending to Propeller TV and see what happens...