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Anyone know what the loudest level for a mix on broadcast (CBS) television is?

Im doing a mix that may end up on there and Id rather not have it smashed by their compressors. :)

I read the other post on Broadcast Levels and what I got was a -10 reference and no higher than a -6 peak. Is this correct?

My guess is either -10 or -12 and a -8 peak.

Its probably on their website somewhere in the fine print. Ill check there as well.

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6 Answers 6

up vote 3 down vote accepted

Roger has given you some good advice, and the ITU-BS.1770 spec is now the reccommended measurement practice in the U.S. as determined by the ATSC. And while I don't know that -24LKFS is what CBS is requiring, I do know that that is NBC's standard and also a common standard in the EU. Georgi is also correct in that every station has their own spec, making it hard to know.

The reason why you have a hard time getting any kind of general standard information other than the -10dB brickwall limit (which is based on limits of the physical tape and some of the broadcast tools in the final chain), is because these measurement schemes are based on the response of the human ear and our brain's interpretation. Standard meters will tell you the overall signal strength of a program, but that does not correlate to how we hear. Different spectral balances have different perceived volumes from one another, these measurement protocols (ITU-BS.1770 and LeqA) are ways to account for perceived volume level across the spectrum.

Your best bet, if you can't find the standards somehow, is to just make it sound good in a well calibrated room. Keep your peaks from exceeding -10dB, and deliver a good mix within the remaining dynamic range. If you do that, the chances that a mix will get kicked back are very low.

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Thanks Shaun, it shall be the plan! -10 and lower is what I am aiming for. –  C3Sound Nov 2 '10 at 15:27

Noone's ever given me a really solid answer to this question either. My guess is that's because it varies from broadcaster to broadcaster.

What i've been doing as a general, safe, method is a -10dBFS max peak, but you also have to take care of your average level:

With Dolby Media Meter (around $800), i've been aiming for a dialnorm of -24dB LKFS (with dialog intelligence turned OFF). Apparently this is a pretty widely accepted dialnorm.

If not, you can use Phase Scope (free!) to roughly get the same thing. Under "Levels" set it to BBC (where it says Peak); click on the LEQ(A) button and in the bottom panel, set it to analyse 10 sec. I've found that an average level of -27dB in Phase Scope with these settings equates roughly to -24dB LKFS.

That's just my plan; if any vets want to chip in, that'd be great.

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there is no solid answer. despite attempts to standardise this, every station still have their own specs. cheers for the tip on Digirack Phasescope. –  georgi Nov 2 '10 at 9:21
    
I was wondering about the LEQ on Phasescope vs an LM100, guess it'll be the same. Cheers Roger! –  ianjpalmer Nov 2 '10 at 14:22
    
Def answered the q! Yep, got phase scope - I use that for dialog leveling as well -- in addition to the Dourrough Meters which are supposed to be very good. –  C3Sound Nov 2 '10 at 15:27
    
@ianjpalmer @georgi.m @C3Sound : I should disclaim that, while running them both together, i've noticed that they respond slightly differently. I wouldn't say they're identical, but they do roughly correspond to one another (with a 3dB difference). –  Roger Middenway Nov 2 '10 at 17:44
    
Thanks for the info on the phase scope! –  user6513 May 8 '11 at 13:52

I deal with this every day...DEFINITELY call CBS and ask to speak to someone in their Technical department to get the specs. Better yet, your producer should already have these specs, so ask them to send them to you. Every single broadcaster has slightly to WIDELY different specs to hit, and often different specs from just Stereo to Surround.

It's VERY VERY VERY important to get and understand these. It's not only an issue of it not sounding good on air. Most broadcasters will bounce back your show if it's not within specs, causing you to have to redo it (thereby losing $$$) and annoying the Producer a LOT -even if the Producer says the mix is great and not to worry about it. Most also have specs about stereo phasing, distortion, sync and so on, so it pays to know WHAT marks you have to hit.

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Its a team effort -- this is a production team being built in LA that I was called out to be on production dialog, and posting back at my hometown. Everyones very experienced from Iron Man 2 to the NFL - but none are in sound. No doubt it is important! It was driven into our skulls at VFS that its always different for each broadcaster, and that getting it right the first time will save money. –  C3Sound Nov 2 '10 at 15:31
    
Not just money @C3Sound, but reputation too. If you keep getting kicked back for tech specs, at some point the producer will just assume you don't know what you're doing and try someone else. Do your work justice and always request a copy of the QC specs when you begin a job for a broadcaster that's new to you. –  Steve Urban Jan 7 '11 at 18:44

not sure if these will help you:

http://www.aptonline.org/aptweb.nsf/vOtherDocs/Services-Technical+Specifications

but you're best to get in touch with CBS themselves and they'll be able to give you their tech specs.

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Thank ya, ill check it out –  C3Sound Nov 2 '10 at 15:31

Can someone explain LKFS and LEQ(A)? The meters I use are all full scale and I'm curious how these relate.

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WGN America requires -20 for unity gain.

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