Audio system with sound-field-type nature sound effect

An audio system with sound-field-type nature sound effect, comprising:

• a first primary channel playing device for playing a primary audio signal generated according to a left channel audio signal and/or a right channel audio signal;
• a first secondary signal circuit for generating a first secondary audio signal according to the left channel audio signal and the right channel audio signal;
• a first sound field control playing device connected to the first secondary signal circuit and adapted to play the first secondary audio signal;
• a second primary channel playing device for playing the right channel audio signal;
• a second secondary signal circuit for generating a second secondary audio signal according to the left channel audio signal and the right channel audio signal;
• and
• a second sound field control playing device connected to the second secondary signal circuit and adapted to play the second secondary audio signal;
• wherein a first playing delay period exists between the playing of the first secondary audio signal and the playing of the primary audio signal;
• wherein the first secondary audio signal played by the first sound field control playing device does not undergo audio mixing with the primary audio signal by a first audio mixing circuit;
• wherein the primary audio signal is the left channel audio signal;
• wherein a second playing delay period exists between the playing of the second secondary audio signal and the playing of the right channel audio signal;
• wherein the second secondary audio signal played by the second sound field control playing device does not undergo audio mixing with the primary audio signal and/or the right channel audio signal by a second audio mixing circuit.