A karaoke amplifier is a powered amplifier specifically designed for the needs of the avid karaoke equipment owner. Many are designed for the karaoke DJ, while some are more designed for home use. They are generally designed to make karaoke equipment easy to connect and disassemble and provide many additional functions over a typical PA system power amplifier.
These features usually include features that any DJ would appreciate. For example, many of the karaoke amplifiers are considered hybrid amplifiers because they have characteristics normally associated with preamps.
One of these features is the multiple inputs so you can send audio signals from multiple sources. This eliminates the need for a mixer if you have two audio sources, such as the karaoke source and an iPod for fill-in music. Many of these units also include a radio tuner.
A typical karaoke amplifier has enough power to drive four or more speakers efficiently. For a good karaoke setup, you will need 2 main speakers, at least one subwoofer, and at least one monitor speaker. The main speaker and the subwoofer work together to transmit all the sound to the audience.
The monitor speaker is there so the singer can hear himself. Quality amplifiers for karaoke and other DJ applications have a built-in crossover, which means that the low frequencies for the subwoofer only go to the subwoofer, keeping it from the rest of the mix. The best way to run your speakers is to run your mains and monitors on the same channel, as high frequencies don’t need as much power.
Make sure to match your amp to your speakers and vice versa. You want to make sure your speakers can handle more power than the amplifier can put out, but not too much. For example, if your amp can produce three hundred watts, then speakers that are rated to handle four hundred and fifty watts would be perfect.
If the amplifier can produce eight hundred watts, then a single speaker must be able to handle a thousand. However, when you’re running that many watts, you’re likely running multiple speakers. In this case, add up the power of each to determine how much they can handle. At eight hundred watts, you could run two five hundred watt speakers (or even four hundred and fifty), or four two hundred to three hundred watt speakers.
The other side of the coin is buying a subwoofer rated at 1,500 watts and only running it with a 300 watt amplifier. You will likely burn out the amp and never get good sound from the speaker because you need more power than you are getting just to produce the sound properly.