     buffer.getChannelData(0)[0] = 1;
        let source = context.createBufferSource();
        source.buffer = buffer;

        let iir = context.createIIRFilter([1], [1, c]);

        // Create the graph
        source.connect(iir);
        iir.connect(context.destination);

        // Rock and roll!
        source.start();

        context.startRendering()
            .then(function(result) {
              let actual = result.getChannelData(0);
              let expected = new Float64Array(actual.length