import com.sun.media.sound.ModelAbstractChannelMixer; //导入依赖的package包/类
public static Soundbank createTestSoundbankWithChannelMixer() {
    SF2Soundbank soundbank = createTestSoundbank();

    SimpleSoundbank simplesoundbank = new SimpleSoundbank();
    SimpleInstrument simpleinstrument = new SimpleInstrument() {

        public ModelChannelMixer getChannelMixer(MidiChannel channel,
                AudioFormat format) {
            return new ModelAbstractChannelMixer() {
                boolean active = true;

                public boolean process(float[][] buffer, int offset, int len) {
                    for (int i = 0; i < buffer.length; i++) {
                        float[] cbuffer = buffer[i];
                        for (int j = 0; j < cbuffer.length; j++) {
                            cbuffer[j] = -cbuffer[j];
                        }
                    }
                    return active;
                }

                public void stop() {
                    active = false;
                }
            };
        }

    };
    simpleinstrument.add(soundbank.getInstruments()[0]);
    simplesoundbank.addInstrument(simpleinstrument);

    return simplesoundbank;
}