This study uses the self-homodyne detection and analysis cavity conversion method to compare the quadrature component noises of all-solid-state single-frequency laser and fiber laser suitable for the preparation of the squeezed-state light field in audio-band frequencies. The results show that the quadrature amplitude and quadrature phase noises of the all-solid-state, single-frequency, 1064 nm laser reach the shot-noise limitation after analysis frequencies of 1.5 MHz and 5 MHz, respectively. Moreover, the measurement bandwidth of the fiber laser is higher than that of the shot-noise limitation. With the semiconductor optical amplifier (SOA) noise-reduction system, the low-frequency-bandwidth (<620 kHz) quadrature amplitude noise of the fiber laser is smaller than that of the all-solid-state single-frequency laser. This result provides a single-frequency source-selection scheme for the study of the low-frequency-bandwidth squeezed-state light field. The SOA noise-reduction system can effectively suppress the quadrature component noise of the low-frequency-bandwidth laser and provide an evidence for the preparation of the squeezed-state light field in audio-band frequencies.