|Posted on February 28, 2010 at 12:56 AM|
Some mixing info from Danijel... cool stuff. Standard Mixing Levels for Movie Theater, DVD, TV, Radio and Games
This post should serve as a little guide to the resources availableon-line on the topic of audio levels in different media. It has beencompiled due to the big frequency of questions on the topic, and thanksto the big amount of answers in this forum!
Since audio in media is an ever-changing field, this post will beupdated as I stumble upon new and interesting infos or links. If youhave insight into data that you think should be included or corrected,please PM me, or post it here.
For further, specific questions on mixing levels, you can post in this thread, or start a new one.
There are no guidelines in terms of average loudness, peak or any otherlevel measurement. You achieve proper levels by properly calibratingyour listening environment, so that it resembles the environment of thetheater.
To calibrate your room, read this:
DUC: Room Calibration for Film and TV Post
(or, in a nutshell)
Then mix by ear. "If it sounds good, it is good" - JoeMeek.
Here's a useful discussion:
FILM & Broadcast - Levels
However, there is a maximum loudness level for theatrical trailers andcommercials which is measured with the Dolby Model 737 SoundtrackLoudness Meter.
Trailer loudness should not exceed 85 dB Leq(m), as regulated by TASA.
Commercial loudness should not exceed 82 dB Leq(m), as regulated by SAWA.
Here, same rules apply as with the theatrical mix, except that themonitoring is different (near-field, no X-curve), the room is smaller,it is calibrated lower, AND there is the dialnorm parameter if yoursound is AC3 encoded.
Read about dialnorm here:
Geo's sound post corner (section about Dialogue Level)
Home Theater Hi-Fi: Dialogue Normalization
You have to determine your target dialnorm BEFORE you start mixing, soyou can adjust your listening level accordingly. Most DVD's are mixedfor dialnorm -27dB (because that setting is the most compatible withthe theatrical mix), but some use the full dynamic range (-31dB).
TV (everything BUT commercials)
Every broadcaster has it's own specs. You have to get the specs of your target TV channel.
They can be very detailed, like the Discovery specs or the PBS specs(section 3). They will tell you exactly what is your max peak level,average dialogue level, average overall level, what measurementinstrument is to be used etc. Meter that the networks usually specifyis Dolby LM100.
Here are two threads about mixing against LM100:
Mixing with the Dolby LM100
Anyone have experience mixing while adhering to specs monitored by the Dolby LM 100?
This is great! A post by Mark Edmondson, Audio Post Production Supervisor at Discovery:
Dolby LM100 and Discovery deliverables - Digi User Conference
The other extreme is on the minimalistic side, like the RTL or BBCspecs which give you only the maximum peak level, and the referencelevel. This is what it's like in most of Europe, AFAIK (if you havesome bogus specs to share, please post some links).
- REFERENCE LEVEL - it is used for equipment alignment, and doesn't have a direct relation to actual mixing levels.
In EBU countries it is -18dBFS and corresponds to electrical level of 0dBu (per EBU R68).
In SMPTE countries it is -20dBFS and corresponds to electrical level of +4dBu (per SMPTE RP155).
Sometimes refered to as: Zero level, Line-up level, 0VU.
Broadcast Audio Operating Levels for Sound Engineers
Reference Levels on Common Metering Scales
The Ins and Outs Of (Sound on Sound)
- MAXIMUM PEAK LEVEL - this is where you set your brickwall limiter onthe master buss, or otherwise not go over it (although in some of thespecs, short peaks of 3 to 5 dB over this value are allowed - gofigure!).
What can make the confusion here is that the average dialogue level is not exactly specified.
In a perfect world, you would calibrate your listening environment tothe ITU-R BS.775-1 standard (-20dBFS pink @79dB SPL/C/slow), [or EBU3276 and EBU 3276-S if you are in Europe] and then mix by ear. In thatcase you would get average dialogue levels at around -27dBFS RMS.
However, this way, your mix could turn out too quiet, as there's aloudness war in broadcasting, probably in part due to the loudness ofcommercials and the loudness war in music. (e.g. PBS has upped theirdialnorm from -27dBFS to -24dBFS in 2007).
Average dialogue loudness that works for me (dramatic program, regionalstations in the Balkan peninsula) is -22dBFS RMS. To achieve that, Icalibrate my monitoring to 74dB, and thus reduce the headroom by 5dBwhen compared to the ITU's 79dB reference.
However, your best bet is to talk to someone who regularly delivers forthe given broadcaster or in a given market, and ask him about hisaverage dialogue level, or how his listening is calibrated. Chances aresomeone at this forum will be able to help, too.
More about broadcast delivery specs:
Geo's sound post corner
A great intro to broadcast audio:
Audio for Digital Television
All this and much more:
CAS Seminars - 'What Happened to My Mix?' - The Work Flow From Production Through Post Production - Cinema Audio Society
Dialnorm was to be implemented in broadcast too (as Dolby imagined), but it isn't, so far:
DTV Audio: Understanding Dialnorm
Food for thought on setting up variable monitoring level:
Bob Katz - Level Practices
Again, you have to get the specs of your target TV channel, but youwill most likely only use the max peak value they provide. Below that,you can compress as much as you wish - it's a loudness war, similar tothe one in popular music production.
There are efforts in regulating this problem:
US: H.R. 6209: Commercial Advertisement Loudness Mitigation Act (GovTrack.us)
UK: UK commercials for TV - perceived loudness issue - Digi User Conference
I can't say much about radio levels, so perhaps someone who is experienced with radio could chime in.
Here's a BBC technical specification, but I don't know how much it applies to different radio stations:
BBC Radio Resources // Programme Delivery // Glossary
Less is more (straight from the horse's mouth) - Bob Orban talks about what goes on with your mix in the radio station:
Radio Ready: The Truth
Absence of standards:
Video Game Reference Level/Standards
THX: Establishing a Reference Playback Level for Video Games
A thread at SDO with some advice and some official information from Sony and Microsoft:
Niveau Sonore en jeux vidéo :: Sound Designers.Org (Babelfish English translation)
(Note: the Xbox360 document is in English)
ms georgia hilton mpse cas