Before the invention of the laptop and MP3, club disc jockeys (DJs) were forced to haul crates of records to parties, raves and other gigs. Today, thousands of songs can be stored on a laptop's hard drive, allowing increased DJ mobility simply by connecting a few cables to the power amplifier and remaining audio system. While the steps to connect a laptop to an audio system are essentially the same to its traditional counterpart, DJs must make sure proper cables are used to connect to the power amplifier.
Locate the laptop's headphone or line-out jack. These jacks are typically located on the left or right side of the laptop itself. Plug the 1/8" side of your stereo cable into this jack.
Insert the 1/4" side of the stereo cable into the LINE-IN or Channel 1 input of your mixer. Switch the mixer and laptop on and begin playing music from the laptop. You will be able to hear the music by setting the mixer's proper volume levels (usually noted by a fade knob) and connecting headphones to the mixer's headphone jack.
Find the MAIN OUT jacks on either the front or the rear of the mixing board (these jacks are typically 1/4" in diameter). Connect one end of the 1/4" Y-stereo cable (left and right channels) to these jacks. Also, ensure the other end of the Y-Stereo cable connects to the Line IN jacks of the power amp.
Pay attention to the right and left channels as they have to match to work correctly. They are usually colour-coded (left for white; right for red).
Connect one of the 1/4" mono speaker cables from the power amp's LEFT MAIN OUT jack to the speaker's LEFT MAIN IN jack (usually located on the back of the speaker).
Connect the other 1/4" mono speaker cable from the power amp's RIGHT MAIN OUT jack to the speaker's RIGHT MAIN IN jack (again, usually located on the back of the speaker).
Rather than setting up a power amp and mixer, try working with a powered mixer. Powered mixers eliminate extra cables and time as they allow you to set volume levels and connect directly to speakers.
Be sure the power ratings of the speaker can handle the output of the power amp. Amps that are too powerful can distort and ultimately damage speakers. Read the owner's manual of the mixer and power amp to guarantee proper connections. Make a note if your mixer and/or power amp outputs via XLR or 1/4". If so, ensure you have the proper cables. Don't connect a mono cable to the laptop as it will only produce one channel of music (the Left Channel).