Ever wonder how DJ turntables really work? People often see DJ gear and become intimidated by the complexity of the nobs and faders and sheer amount of controls available for manipulating sound. Back in the day record turntables did all of these things themselves. They were analog audio players that were allowed to be adjusted by users to create new and unique sounds with source audio from records or CDs and help from electrical effects.
You could adjust the BPM of the song by adjusting how fast the audio signal played by physically slowing it down. Or you could adjust how loud each record played to make transitions from one source to another. The physical turning of the record set the pace, and the music was turned into electric signals for the speakers. Between the speakers sat electronic filters, much like electric guitar pedals that would create effects and frequency response changes, adjusting the play out of the song. These changes were all analog, adjusting how the signal was interpreted (making it slower, or ignoring bass), but not through active reprocessing. The signal was read differently, not processed.
These good old days are truly becoming old school and companies look at gear like this a niche market. The majority of the focus goes into making new electric DJ controllers. It’s picked up as the cost of electric components and circuitry has become more powerful and cheaper for manufacture. These new turntables have gone binary. The manipulation and even the audio sources themselves have gone digital, and are run through CPUs instead of the older method of analog alterations.
Today modern DJ turntables work as peripherals and don’t adjust the signals themselves. Now new DJ setups require a computer with audio editing software dedicated to DJing, a Dj controller, an audio card, and a sound system. Essentially all the work falls into the lap of the laptop. All the audio is stored on it’s hard drive, all the audio adjustments are controlled through it’s software, and all of the alterations and processing is done by it’s CPU. In fact DJ controllers do none of these things. They are glorified specialized keyboards, allowing for an alternate way to converse with the laptop.
A DJ controller works by connecting to a laptop via USB. The DJ then maps the buttons, faders and nobs to menu settings and selections in the software on the computer. So in essence, pushing the auto-sync button on the controller merely hits the auto sync button in the DJ software and the computer does all the work. Larger turntables just give more options and more control over the software and can be mapped in any way you choose.
Some controllers come with an onboard audio card. This premium option allows for the audio output of the DJ software to be sent back to controller digitally over the USB cable and through the audio card. These sound cards allow for the DJ to adjust audio levels to outputs much like an audio mixer, through choosing channels and controlling the sound system. Turning the digital signal to analog sounds. So controllers can do some work in the signal chain. But the vast majority of the show is still done on the laptop. Even if you’re spinning the jog wheels instead of scrolling the mouse.