"Void" is a sound performance that explores the range of frequency in an empty space. The sound is produced in a closed glass tube by generating audio feedback, and I attempt to push the sound at the very limit level towards both low and high frequency within the audible scale. The sound starts from nothing in empty space (void) and it becomes amplified as time proceeds. The range of audio frequency is controlled by oscillating, modulating and shifting the hertz when the space is closed and open. Also, environmental factors influence the sound amplification, working like triggers. Different DIY devices are used to create additional sound. These make different ways of feedback between multiple inputs and outputs. The audience will listen to a wide range of sound from very low to very high and fluctuations of the sound waves in different time settings.