A sound system is a collection of electronic components that process, amplify and reproduce music or other audio signals for playback over speakers. The fundamentals of any audio system are sound source, processing and output, but the details differ from a car stereo or home speaker to an arena PA or studio recording setup.
Most of us have some experience with listening to music, whether it’s a personal CD player or streaming over the internet. We know what it sounds like to use headphones or stereo speakers and we’re familiar with the sound quality difference. What we may not realize is that there is a lot more to the audio chain than just that.
Sound systems vary in size from tiny personal portables to multi-kilowatt setups for stadium concerts. However, at the heart of any sound system are the same basic components: Sound sources, amplifiers and loudspeakers. It’s not just about the wattage, though – it’s the physics of how the systems work that make them sound good or bad.
The first step in any sound system is the input/transduction stage. The audio signal from the source must be converted to an electrical audio signal. This happens in the microphone, which translates vibrations (acoustical energy) in the air into an electric current by vibrating a diaphragm within a magnetic field created by a voice coil. This electrical signal is then fed to a power amp, which amplitudes the signal for later output through the speakers.
Depending on the type of system, the next steps may include mixing and effects. A mixer may mix multiple audio sources and add audio processing such as EQ, delay, reverb and more. Effects such as reverb can increase the perceived depth of an environment. These components are often called a “control room,” and are centralized in the main PA system to keep the audio signal as clean as possible for long-distance transmission.
The final step is the output/echo stage, which converts the amplified electrical signal back into acoustic energy that we can hear. The speaker system converts the electrical signal into sound waves, which are then reflected off the walls and ceiling and played through the speakers for our ears to enjoy. This is why it’s important to get the right speakers for the application – they’re the final link in a system that delivers a great sound experience. The speaker’s size and geometry are also key factors to consider for the best results. Ultimately, the goal of a sound engineer is to deliver a great-sounding system to the audience that will enjoy it and be happy with the experience. This is accomplished by a combination of objective goals and measurements, as well as subjective toning. The more you understand the physics of the sound system, the better your chances are of success. Good luck..