Web Audio API creating a Peak Meter with AnalyserNode

What is the correct way to implement a Peak Meter like those in Logic Pro with the Web Audio API AnalyserNode?

I know AnalyserNode.getFloatFrequencyData() returns decibel values, but how do you combine those values to get the one to be displayed in the meter? Do you just take the maximum value like in the following code sample (where analyserData comes from getFloatFrequencyData():

let peak = -Infinity;
for (let i = 0; i < analyserData.length; i++) {
  const x = analyserData[i];
  if (x > peak) {
    peak = x;
  }
}

Inspecting some output from just taking the max makes it look like this is not the correct approach. Am I wrong?

Alternatively, would it be a better idea to use a ScriptProcessorNode instead? How would that approach differ?