Questions on Broadcast Specs

[sundontlie]

I mix a few shows that air on The Food Network. Their deliverable specs for audio are:
ref tone at 0db (VU)
average audio levels at +5 to +10 db above ref tone
peak audio levels +10 db above ref tone

My company prints reference tones at -20db. They can not tell me way they don't print ref tone at -18db? (I will be calling a tech person at The Food Network to help me with that, maybe there is a reason I am unaware of). This means to stay legal, I can peak at -10db and average close to that for overall audio levels.

I keep my dialog levels very close to the peak point and do a 2 staged compression to try and maximize volume and avoid peaks. Though, I have noticed when checking my mixes against other channels that The Food Network has a much quieter broadcast audio level then other cable networks. This is not just my shows but the entire network all the time.

I am thinking that either other networks have a higher average audio level tolerance (say -8 or -6db) or maybe the networks have different audio compressions that make the output level higher after the fact.

Can anybody help me with this?


Does anybody know some other cable networks broadcast audio specs, so I have something to compare mine to? Or have a better understanding of this problem and can point me to some reading material on the subject?

[minister]

sundontlie,

the American standard is -20 = 0VU. Why do you want -18?

Food Network cares nothing but that you do not exceed -10 on peaks.

[robertocap]

The key as mentioned above is to keep the peaks 10dB above your reference. If your post house runs at -18, then you will have to drop your levels by 2dB when outputting to tape. Most decks are now defaulted to -20dBfs anyway - your facility should changeover when possible...

Different broadcasters have varying level strengths for their signal - some 'hit' the satellite harder than others. Each broadcaster has their own peak specs - at least 1 in Canada demands that you Never exceed +8dB over referenceas they could reject the show. Others are more loose in their requirements and acceptance.

Most mixers concern themselves with how their mixes sound on a particular broadcaster - does your mix sound as loud as other programming on that channel for example. I have had some of the shows I have mixed appear on more than 1 network and the show sounded different on another channel - ie. more compressed.

It is best to always meet the specs for a variety of reasons, even with broadcasters who are not particular with their levels. If you do not, they will either 'turn down' your show , or let the transmitter's companders bring it in line . You never want that - I have been in a few Master Controls and transmitter racks and you do not want one of those companders touching your material if it does not need to!

[sundontlie]

Thank you robertocap for your reply.

As far as -18 goes, I was mistakenly saying AES guidelines not the Motion Picture guidelines which are -20db. We print our ref tone at -20db. Thank you for clearing that up.

My mixes work well inside the network and have similar volume when compared to other shows.

I guess I am just interested with overall network levels channel to channel and the different specs that each network asks mixers to deliver.

Your thoughts on broadcast signal strength is sort of what I was thinking was happening. Thanks.

Shows like Smallville have dialog just as loud as other networks and then are able to have peaks for sfx that seem to be hotter still. This just makes me wonder what specs they are mixing to and what they are delivering level wise?

[Bob Olhsson]

FWIW -20 VU is equal to -18 RMS. The tones are at the same level but the meter is different.

[dr sound]

Poster: sundontlie
Subject: Re: Questions on Broadcast Specs

SNIP
Shows like Smallville have dialog just as loud as other networks and then are able to have peaks for sfx that seem to be hotter still. This just makes me wonder what specs they are mixing to and what they are delivering level wise?

dr sound replies:
Smallville is mixed by two very good friends on mine. Dan Highland CAS on Dialog and Music, and
Gary D. Rogers CAS on FX and Foley. Gary was nominated for an Oscar for his Mixing on "Hunt For Red October". We use to work as a team and won a couple of Emmys together. He is a HELL OF GREAT FX MIXER!!
It's more than meters!

[Richard Fairbanks]

FWIW -20 VU is equal to -18 RMS. The tones are at the same level but the meter is different.

Huh?

[ILOVEPROTOOLS]

All i can add to this is I've mixed for a cable network that had -16 db as a peak level.... another one that had -10.... a major broadcast station whose peaks were -2.... and I do my commercials at-6db which seems to mix well with everything else on tv... i just did a -10 commercial for a -10 network and when aired on a different network it sounded weak in comparison to the other spots. ....no sh*t! the same -10db commercial just came on BET while i'm typing this and it sounded great in comparison to the other commercials and the movie (leprechaun) thats airing.... Any enlightenment on the subject would be greatly appreciated.

[robertocap]

Hi Sundontlie,

You may want to post your question, if you have not already done so on sound design@yahoogroups. There have been some discussions there regarding this issue. You are not the only one who is curious about levels - most of us are!

On an animated series I recently worked on, the international specs, as QC'd by Technicolor here in Toronto, would accept a Maximum -9dBfs Sustained level and the occasional short -7dBfs peak. Certain broadcaster may differ and prefer more conservative levels.

As Dr. Sound noted, and you probably already know, it is the psychoacoustic qualities of the sound chosen that matter more than the actual peak value. Selecting the right sound/mix of sound effects with particular care to choosing f that will 'jump' out at you on your TV set is very important. You could have a foley hand slap or pat that would peak out at -4dBfs, but not sound as loud as a punch compressed and max peaked at -10. I am sure there are better examples than mine out there!