Audio analyzers are dumb. They just deliver data.
Our job is to interpret that data from Smaart or SATlive or SIM3 (well, if you’re reading this…you probably don’t own a $10,000 SIM3). But we can’t do that if the data is bad.
Here is a collection of my best tips on getting good data with your audio analyzer:
- Double check all connections. This is the most common problem I run into. You accidentally plug the microphone into the reference channel. If checking the connections doesn’t help and you are doing some fancy routing with your mix console, go back to a simple Y split from the output of the audio analyzer instead. If everything is working, you should be able to make a change on your system EQ and see it reflected in the analyzer.
- Measure at an appropriate level. The great thing about the audio analyzer is that you don’t need to blast everyone with pink noise, but you do need to get it up above the noise floor by 20 dB at all frequencies you want to measure for good coherence.
- Use coherence blanking. Sometimes you’ll take a measurement that will go all the way down to 20 Hz, but you know the speaker only really goes down to 80 Hz. What’s happening? The rest of the measurement is noise, which you can see in the coherence and phase trace. Bring up the coherence threshold until the noise disappears.
- Use more averages. You’ll need about 1 second for normal conditions and 3 for noisy conditions. If that doesn’t work, set your averages to infinite, then just keep measuring until the coherence stops improving.
- Do your Main+Sub alignment in the nearfield. I have had so many headaches trying to complete a Main+Sub alignment in the far field. It’s tough to get good data because you are no longer measuring direct sound from the sub, you are measuring a million other reflections that are just as loud or louder than the direct sound. After you do your alignment in the nearfield, you can adjust it for any distance offset with a laser distance measure.
- Measure subs at ground plane. If you’re doing an LF measurement and having trouble getting a stable trace, try a ground plane mic position. This will remove the floor bounce.
. It’s everything you wanted to know about live sound system setup, but were afraid to ask.