Using an RTA to Improve Your Church Livestream Mixing

Getting clear, consistent audio for your church livestream can be challenging. This is especially true when mixing remotely. You can’t always trust what you hear through headphones in a different environment, potentially hundreds of miles away. What sounds balanced in your headphones might be muddy or harsh to folks listening on their phone speakers or home televisions. What if you had a tool to visually confirm what your ears tell you and provide an objective reference point regardless of your listening setup? Enter the Real-Time Analyzer (RTA).

What is an RTA?

A Real-Time Analyzer, or RTA, is an audio measurement tool. It provides a visual snapshot of your sound’s frequency content as it happens. Imagine a graph:

The horizontal axis shows the range of human hearing. This goes from low bass (left) to high treble (right). It’s typically 20 Hz to 20 kHz.
The vertical axis shows the loudness (amplitude) of each frequency band in decibels (dB).

RTAs use Digital Signal Processing (DSP) and math techniques like the Fast Fourier Transform (FFT). These methods break down the audio signal into its component frequencies. The RTA then displays the energy (amplitude/loudness) in specific bands of frequencies.

Basic RTAs might show 10 bands (octave) or 30 bands (1/3 octave).
More advanced software can display much finer resolutions like 1/6th, 1/12th, or even 1/24th octave bands, offering a more detailed view.

Essentially, an RTA displays how much energy is present across the frequency spectrum at any given moment. This energy would look like individual level meters for different tonal ranges.

Why is Using an RTA to Improve Your Church Livestream Beneficial?

For livestreaming, an RTA offers several key benefits.

Enhance Vocal Clarity: Visually check if speech frequencies (around 1 kHz to 4 kHz) for the pastor or worship leader cut through the music. This helps you make EQ adjustments for better online intelligibility.
Balance Music and Speech: Ensure worship music isn’t overpowering the vocals. An RTA helps identify instruments clashing in certain frequency ranges, allowing for targeted EQ cuts to create better separation.
Improve Mix Consistency Week on Week: Since an RTA provides an objective visual reference, you can use reference curves and establish a visual target for mixes week after week. This reference could aide in getting to a consistent mix, no matter who is mixing or what their listening environment is like.
Identify Problematic Frequencies: Sometimes a mix feels “too loud” because of room modes, instrument characteristics, etc. An RTA helps pinpoint problematic frequencies and enables targeted EQ cuts to avoid turning down everything.

RTA Types and Connecting an RTA for Your Church Livestream

While there are hardware options, most engineers now use software plugins. These run within mixing console software/DAWs or standalone apps. Some examples include Open Sound Meter or Room EQ Wizard (REW).

To analyze your livestream audio (not the room sound) when using an RTA to improve your church livestream:

Route Your Stream Feed: Send a copy of your main livestream audio mix. This is often a dedicated Mix Bus, Aux Send, or Matrix output. Send it to an available physical output. This ensures you analyze the exact mix sent to your streaming encoder.
Connect to Device: Connect this console output to an input. Use your computer’s audio interface. Or use a compatible interface connected to your tablet/phone running the RTA software.
Select Input in RTA: In your RTA software or app, choose the connected audio interface input. Make it the measurement source.
Don’t use the device’s built-in microphone. This analyzes sound in your room, not the actual livestream audio feed.

(Note: Using an RTA with a measurement microphone in the sanctuary is common. It tunes the main PA system to the room. Pink noise is often used as a test signal. However, analyzing the livestream mix itself requires a direct feed from the console.)

Using RTA Readings in Your Church Livestream

Let the RTA guide your mixing decisions. But don’t let it dictate them. Always trust your ears first. This applies even when using an RTA to improve your church livestream. Here are a couple of categories you can use the RTA to improve your church livestream mix.

Pastor’s Mic: When the pastor speaks, does the RTA show a significant bump between 200 Hz and 400 Hz? This indicates potential “boominess”. Make a small, targeted cut in that range on their channel.
Band Balance: Observe RTA curves during worship. Do low frequencies from bass or kick drum dominate the RTA? Do they seem to mask vocals? Make cuts to low and mid range frequencies if needed. Experiment with using slow averaging on the RTA to give a better sense of overall balance across changing musical sections.
Feedback Hunting: Suspect feedback? Slowly bring up the suspected channel’s gain and look for a frequency band spiking much higher than others. That’s likely where you’re hearing feedback.
Overall Check: Observe the RTA’s general shape across the whole mix. Aim for a balanced curve and avoid extreme peaks or valleys. Listen carefully through headphones and then check the stream on consumer devices.

Know the Limits

An RTA is a powerful tool, but it has limitations like:

being “time-blind.” RTA shows what frequencies are present but doesn’t show when they arrived or why they are loud^.
can’t distinguish direct sound from room reflections. It can’t diagnose phase and polarity issues. For that level of analysis, dual-channel FFT analyzers (like Smaart) are needed, which compare the console output to a measurement microphone signal, although these tools require more expertise.
For livestream mixing, the RTA provides valuable spectral information. But critical listening remains paramount. This is true even when using an RTA to improve your church livestream.