Mixing levels for Dolby Digital: DVD vs. theatrical

[Lee Sharp]

I thought of something the other day

Why as location mixer do we have to not peak more than -10dbfs.... why cant we get as close to 0dbfs as possible and then let post sort out the levels for boradcast standards later?

Wouldnt this acheive a better S:N?

Long as we are careful at not clipping, -12DBFS is still quite low isnt it?

[Steve House]

You're correct, but with a strong caution. The "no peaks over -10dBFS" refers to the final delivery mix and usually for SD broadcast. Theatrical, DVD, HD broadcast mixes can be hotter. The caution when recording original source materials is that even peak reading meters have a limit to their resolution and audible clipping can occur even with peaks too short to register. Source material with a dynamic range of 16dB+ is not uncommon. It's better to be a shade low than a shade high - you raise the level a bit in post but once you're clipped, you're toast.

[Lee Sharp]

so would you suggest to keep to the guide line of peaks at -10db (EBU) during recording... as post are gonna bring it down lower anyway?


Alsoi read that some people like to line up at -12dbfs when tey know the dialogue is soft so they can oush the signal, but what I dotn understand there is if you line up the recrder at -12 and the mixer is still at 0, how does this help?

Is not not just the same as keeping it at -18/20 and upping the trims on the mixer? Whether boosted more on the trims of the mixer or camera/recorder trims the signals gonna be the same, atleast on the mixer you would know the max headroom on the mixer is close to the recorder headroom, if the other way round the mixer would be barely be near its peak but the recorder would...

[Reggie Moser]

This is definitely good info..... Is there a book dedicated to this audio process or maybe even a website that goes into detail that someone can point me to? Thanks

[Lee Sharp]

Originally Posted by Reggie Moser

This is definitely good info..... Is there a book dedicated to this audio process or maybe even a website that goes into detail that someone can point me to? Thanks

Sound for film and television 3rd edition is due out by thomlinson holman!

But this is why I ask so amny questions because the answers always diff....

i read someone said form day to day keep elvels pf eahc actor the same..... but how is that possible if the peak dialogue varies day to day. On emionute the average dialogue will be around - 18 with peaks at - 12, other scenes may have no major peaks so dialogue can be hotter at -12 thorughout.... so day to day the levles are gonna vary surely and thats then post mixers job to sort out?

[Reggie Moser]

Thanks Lee

[Lee Sharp]

Originally Posted by Steve House

The lineup point is basically related to the amount of headroom the system will have.

You also want to be consistent shot to shot and day to day so that a scene whose dialog metered 0VU on Friday will be the same level as a scene shot metering 0VU on Monday.
l.

How is that possible? Because its the peak of the shot that determines the levels set doesnt it?

monday actor one may have a scene where he shouts for a second, which then make the average spoken level of dialogue quieter. On tuesday actor 1 might have a shot that is all average spoken dialogue, so you can increase the level for a better S:N but that then means Monday and Tuesdays average spoken dialogue level is different... but isnt that then for POST to adjust?


Or have I misinterpreted whats you measnt by consitancy with day to day levels?

Im not entirely sure, otherwise youd have to ride the fader to make average level of spoken dialogue on shots with louds peaks, so theyre not then quiet in comparison to other shots?