Issue link: https://digital.copcomm.com/i/17668
Surround for Spots cial mixing. Unless there is a specific need or event for the LFE, typically I am really making 5.0 mixes with an empty channel for the .1. For example, say I am doing a commercial that has some kind of low-end effect like an earthquake. I mix it for 5.1, but I add in enough to the subwoofer via the left and right channels to carry for the mix.That’s because when I do my down mix to stereo, I do not include the LFE when folding down. I know I don’t have to because I am not putting things solely in the LFE channel, which makes for a much better fold down to stereo.” With the introduction of surround sound Recent surround projects for POP include spots for Jose Cuervo and The Call of Dutygame. mixing for commercials and multiple audio tracks on videotape, deliverables for com- mercials have become more complex. De- pending on the broadcast network, spec for audio levels can be extremely specific and vary greatly.“Audio levels vary from network to network,” says Dickson.“For example the spec for dialnorm on the Dolby LM 100 can be anywhere from -21 to -25 depending on the network. But when I am mixing a com- mercial, I have no idea where it’s going to play. I am doing one commercial mix that is going to go to NBC, Fox and any of the cable net- works.That one mix is going to all these dif- ferent places that have all these different re- quirements in terms of levels. I can’t do a mix for every single network based on each one’s indi- vidual spec, so there is no way I can meet every spec of each network with only one mix. I look at all the specs for all the major net- works and mix to the highest one. Otherwise, we would have to make a mix and a master tape for each one, and the time and the cost of that would be so impractical. “Most producers un- To create great images takes real vision derstand that once they see what we are up against,” he continues. “And any network with a lower level requirement can lower the volume. If they don’t, then my spot will play louder.” Dickson’s experience www.digitalvision.tv 40 Post • October 2010 www.postmagazine.com has uncovered a contra- diction within common network specs for sur- round sound and stereo mixes. “When I first started mixing in sur- round, I was getting specs that said it can’t be any louder than -25 on the dialnorm meter. When I followed that spec for the 5.1 mix, I noticed the stereo downmix would come in between 3- to 5dB lower had I just done a regular stereo mix.The problem is that if the broadcast HD tape goes to a duplication fa- cility and an SD version is made, the Lt/Rt mix will play back quieter than the other spots that were mixed in stereo. Clients com- plain when their spots are too low so this doesn’t fly.That’s why I have adapted my mix- ing style to make sure that I am watching my meters on my stereo downmix when mixing in 5.1. I make sure that the downmixed stereo is at the same level as a mix that I would normally do in just stereo.” Audio levels for commercials have always been debated over the years. Short format combined with vastly different types of pro- gram material do not make for a one size fits all approach to audio levels.“Now the biggest issue for me is how the measurements for audio levels are taken,” says Dickson.“For ex- ample, dialnorm is a good way to measure perceived volume over a long duration of time for a TV show or a movie.Those typi- cally have dialogue sections,music sections, and big action sections that all average out over time with the levels. But with a com- mercial, you can have everything all going at once for the entire 30 seconds.That is going to measure off the charts and the mix would have to be lowered based on the dialnorm reading. But if a quiet, peaceful, whisper type spot came on next, that mix would be mixed up to be louder in order to meet the dial- norm level requirement. So a whisper can be mixed as loud as someone yelling based on this type of measuring system.This would give the spot with the whisper a perceived volume louder than the one with the person yelling! That is the biggest flaw with requiring a dialnorm spec for commercials. “I don’t mix every spot the loudest it can be,” continues Dickson.“I mix what is appro- priate for the content and material, but the spec doesn’t take into consideration this type of variation in content. Unfortunately, if you are only looking at meters, and that can be VU meters, peak meters, the dialnorm, whatever, none of these meters take into consideration the program content. Now that is fine for long form, but not for a :30 or :10 spot.They can’t use the same standard for something so different and varied as commercials.The mixes can suffer just for the sake of making these numbers.” Dickson mixes on Pro Tools|HD running Digidesign’s ICON and prefers the URS Pro Channel Strip plug-in.“What is great about