DJ System are usually much smaller than other mixing consoles used in sound reinforcement systems and sound recording. ... The other points along the crossfader's path produce different mixes of A and B. DJ mixers typically have phono preamplifiers to hook up turntables.DJs use audio equipment that can play at least two sources of recorded music simultaneously and mix them together to create seamless transitions between recordings and develop unique mixes of songs. ... DJ software can be used with a DJ controller device to mix audio files on a computer instead of a console mixer.