        let context = new OfflineAudioContext(2, framesForTest, sampleRate);

        // Use a simple impulse with a large (arbitrary) amplitude as the source
        let amplitude = 1;
        let buffer = context.createBuffer(1, testFrames, sampleRate);
        buffer.getChannelData(0)[0] = amplitude;
        let source = context.createBufferSource();
        source.buffer = buffer;

        // Create the two biquad filters.  Doesn't really matter what, but for
        // simplicity we choose identical lo