Loudness, LKFS Metering, and Mixing for TV & Music

I’ve been banking lots of information on LKFS metering and loudness lately. I felt like a summary might help those on the quest. Check it out….

Loudness for TV

Recently I’ve mixed a TV show called “Progressive Bass Weekend Wrap-up Show.” Mixing for television has radically different goals than mixing music. While the fundamentals are similar, the target for TV is all about the broadcast network’s “Quality Control” spec. In this case, Fox provides a complete list of targets for audio. Two of the targets are fairly hard lines and, if crossed, can be a reason for having the show rejected.

Even if you only have music experience for mixing, the first line is easy to understand. “Instantaneous audio peaks shall not exceed -6dBFS, while average peak audio levels should not exceed -10dBFS.” This pretty much means that nothing should ever exceed -6 decibels relative to full scale digital or 0dB. When mixing music, people tend to push it up to the line (0dB) but that’s a bad thing for TV broadcast. One way to deal with this is a “brick-wall” limiter as a safety net. Just make sure you’re not slamming the limiter for everything, otherwise you’d miss the concept of “average peak audio levels should not exceed -10dBFS.”

A slightly more complex problem is LKFS measurements. This stands for “Loudness, K-weighted, relative to nominal full-scale.” This is a fall-out of the recent “Loudness Wars” that have existed in music and broadcast television. If you remember a few years ago TV commercials might cut in from a show and BLAST compared to the regular program. Personally I found it annoying and hated commercials for this reason. Apparently so did Congress who legislated to fix the problem by issuing standards to all broadcasters. Enter the LKFS quality control measurement… thanks to the CALM Act.

The linked article above does a fantastic job regarding LKFS technical details. For those who have the opportunity to mix for broadcast, understanding the technical specs is step one.

What about Music?

The loudness wars are different in the music world. This is really a hot topic for mastering engineers but everyone who creates and enjoys music should get hip to the discussion. Bob Katz has written a ton on the subject and developed the K-system for monitor calibration and metering that has become a standard in the industry. Mixing is not just monitoring peaks. It’s also about controlling dynamic range with musicality and audio monitor calibration and proper loudness metering can be great tools for making a better mix.

For those who are producing music for TV and Film, loudness monitoring can be crucial for creating music that sits well in a post-production mixdown. Read some of the linked articles, watch Bob’s video (see link) and get tools that can help prevent loudness mistakes like the square-wave mix.

The next step if finding a good loudness meter. There are several. Dolby, Waves, TC Electronic, Steinberg, NuGen, and others are available. I spent a fair amount of time researching these and came away with the following observations….

The Meters

Dolby’s Media Meter 2 ($795, VST – RTAS )

This meter is king of the hill for features and royal pricing. It has a few features that set it apart from the others listed but also has the reputation among users to be a system resource hog. I didn’t break my neck looking for it, but it doesn’t appear that Dolby offers a demo version. Buy on faith only…. not for Joe.

Waves WLM ($300, VST – AU – RTAS)

Disclaimer: I really don’t like Waves as a company. I don’t like how they manage updates, upgrades, demo downloads, and I feel that a lot of times their product is overpriced.
That being said, I think this is a fantastic meter design and fairly priced. This plugin supports up to 5.1 and gives DialNORM readings which can be very helpful. It’s compliant with all the standards associated with LKFS and various continental broadcast standards. It doesn’t give a time-history graph though and I really found that useful when using other meters.

NuGEN Audio VisLM ($499 or $299, VST – AU- RTAS)

This one is best in show for my tastes! It comes with two versions; LM-H and LM-C. Having the choice is nice, but the full-featured version won me over. It’s easy on the eyes and makes good use of color to highlight problem areas. Being able to look at the history makes it easy to pinpoint problem areas in the sequence without having to hunt around. PLUS…. the product can be downloaded with a 30-day demo. So try it for yourself.

NuGen’s VisLM-H