In Monday’s discussion on mixing for livestreaming, areas covered included gain structure, levels and panning. Let’s look further into other aspects, beginning with EQ and Dynamics processing.
EQing and Dynamics Processing
Properly EQing each channel can also add space to your broadcast mix. EQing is another way in to keep elements apart from each other, that may otherwise be competing. By eliminating unnecessary or distracting frequencies for each input, you allow for other inputs to fit better into the mix.
The best place to equalize sources is by using a high-pass filter. With a good sounding input, and high-pass filter, you can usually arrive at a pretty good mix.
The high-pass filter helps to dial in where an input should be in the mix, by cutting lower frequencies that rob your mix of much need fidelity. This is the reason why when I’m mixing, rarely do I have inputs that do not have the high-pass filter engaged.
For example: the lowest note on an acoustic guitar is 82.4 Hz, so harmonics below that note could interfere with other sources in the mix. So, a high-pass around 85-90 Hz helps to separate the acoustic and keeps it from interfering with other sources, ones that have fundamental frequencies in that range.
If an input really needs to be tweaked to achieve an optimum sound, then use your EQ filters where needed, but sparingly.
In a broadcast mix, if a harsh EQ boost or cut is applied to an input signal, it can be very noticeable, not just for the source, but other instruments that could be bleeding into that source. If you find that you’re having to over-EQ an input, then it is best to fix issues at the source, rather than trying to correct them at the console.
Compression isn’t just about making things “quieter.” In the context of mixing, compression can be used to control the dynamic range of an audio signal in, helping it stay where you place it in the mix.
With compression, the goal is usually to “even out” the dynamic range of an input, by attenuating loud transient peaks, such as a singer that suddenly belts out a high note or a speaker who is putting a bit too much into the message.
The ability of a good mixing engineer to use compression effectively is truly a life-long learning process.
As with EQ, level, and panning, though, a little goes a long way.
Instead of using higher ratios, it is better to use different levels of compression to control varying levels. It’s best to use lower ratios (2:1 – 5:1) for “leveling out” inputs, particularly sources that have parts that tend to jump out in various places. Then you can use hard limiting for those extremely hard peaks in level. Understand that overcompressing a signal can lead to unnatural sounding sources, by making an unpleasing ‘pumping’ or ‘breathing’ sound.
Effects and Room Mics
Time-based effects such as reverb and delay can be used to give a mix even better stereo image.
Using different time-based effects can give sources the sense of being larger or further away in the mix. Overall, you might say time-based effects are for enhancing the depth, adding the final finishing touches, or providing the final sparkle to a mix.
Reverb is a naturally occurring phenomenon caused by sound reflecting off surfaces in any given room or space. By using reverb in a broadcast mix, it can create the sense of space that a room would provide and is an aesthetic tool that can be used to great advantage.
Without any reverb, a broadcast mix will feel like it lacks three-dimensional space. Just make sure you are using small amounts of natural sounding reverbs, so that the mix sounds closest to an in-room experience.
A few carefully placed room mics can go a long way with helping to connect a broadcast audience with a live experience. Just as cameras give a viewing perspective, room mics establish a listening perspective. Without room mics, a broadcast mix can feel disconnected or isolated from the experience.
The hardest part of about utilizing room mics is finding the right placement. You want to give the audience a sense of space, without washing out the mix with room noise. If the mics are too far away from the audience, then the mics will also not achieve the desired effect and will result in sounding dull. If the mics are too close, though, then you will pick up a few individuals rather than the entire audience.
The best practice for placing room mics is to hang several evenly over the audience, to where they reject audio from the PA and the capture the space and audience perspective of the room.
When it comes to adding room mics into the mix, again less is more.
When the room is loud, room mics will tend to exaggerate what’s happening live. During loud moments, it’s better to bring down the room mic levels and mix them back in, during softer and speaking moments. Another way to think about room mics is in the way of response. Use these mics to translate the audience’s response to the broadcast listener. One example doing this would be if the audience is clapping to the music, laughing to joke, or any other response, then allow the listener to hear that, as it will be a means to bring them into the experience.
The biggest tool that churches are missing when it comes to broadcast mixing is proper metering.
Anytime you’re working on a broadcast mix, it’s helpful to know what levels you are sending to air. Without properly monitoring your levels and stereo spectrum, you can lose perspective at what levels the listeners are receiving, and at worst, be completely out of spec for your streaming service.
There are broadcast standards for audio levels. These standards help even out audio across TV channels, programs and commercials.
Have you ever noticed that you rarely have adjust your TV volume between channels? This is because of broadcast standards for audio level for television broadcast. Generally speaking, in a North American TV broadcast, the audio must measure -24LUFS (loudness units full scale) for the entire length of the program, although this can vary depending on the distributor.
The way to properly meter your broadcast audio is to use a loudness meter. A loudness meter is different than the VU, Peak, or RMS level meters on your audio console.
A loudness meter uses standardized algorithms to measure audio levels across time and uses units such as LUFS to indicate level. Broadcast consoles such as Lawo, Calrec, and others have built in loudness metering.
If you don’t have an audio console with this feature built in, there are plugins and hardware loudness meters available, such as the WLM plugin from Waves or the Clarity M from TC Electronics.
I’ve yet to find an adopted standard for audio levels for web streaming. iTunes, YouTube, and Spotify, for example, all use different level standards for their distribution. What I recommend for people who are mixing for livestreaming, is to stick to -14LUFS as a target level.
When mixing for broadcast, your goal should be to give the viewing audience an experience allowing them to connect with the event, as if they were physically in the room. This is much harder to do than mixing the in-room experience, but if you pay attention to these basic things, you’ll be on your way to improving your broadcast mix.
On this topic, there are certainly greater depths to explore than can be written here.
Spend time researching, practicing, and experimenting with what gives you the best results. Also, be open to well informed feedback, as others can be helpful in having you craft a better mix.
In the end, use your ears to tell you what sounds good and what does not.