Sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid, or solid. Understanding how sound waves are created and how they travel through your audio system helps you make better decisions about the components you choose and how you set them up.
What Are Sound Waves?
Sound waves are the pattern of disturbance caused by the movement of energy traveling through a medium such as air, water, or a solid. They are produced by object vibrations that create pressure waves. Those pressure waves cause particles in the surrounding medium to vibrate in turn, carrying the sound outward from its source.
Not all sound waves are created equal. Each has different frequencies and amplitudes depending on the source. When it comes to audio systems, these frequency variations are constantly changing as music plays — which is exactly what makes music complex and interesting to listen to.
The sound waves produced by speakers and subwoofers are called longitudinal waves. They travel directly from the speaker cone outward toward the listener, with air molecules compressing and expanding in the same direction the wave is moving.
How Your Audio Signal Travels Through the System
From the moment you press play to the moment sound reaches your ears, your audio signal passes through several stages. Each stage shapes the final sound you hear.
The original signal from your media device is sent to the receiver in your head unit, then passed to the amplifier at a very low signal strength called line level. Once the amplifier receives that line level signal, it amplifies it into a higher output signal strong enough to power subwoofers, speakers, and supporting components — creating sound waves substantial enough to produce adequate output for the listener.
How Sound Waves Are Produced by Speakers
The amplifier is the link between the original sound wave produced by the input signal and the frequencies being sent through your system to your speakers and subwoofers. Sound waves are produced when the speaker's cone vibrates in response to the amplified electrical signal. That cone movement pushes and pulls on the air in front of it, creating the pressure waves that travel to your ears.
When you turn up the volume on your favorite song, the amplified signal increases in amplitude. This increases the rate at which the cone moves and how forcefully it displaces air, resulting in louder sound waves and greater impact on your eardrums.
Why Component Quality Matters
Power output, loudspeaker sensitivity, and component quality all determine how much bass response, volume output, clarity, and tonal accuracy your system produces. The better the components, the more accurately the final sound waves replicate the original recording.
If you listen to a wide variety of music ranging from deep bass to high-frequency content, a higher quality amplifier delivering clean, high power will maintain clarity across the full frequency range. Low-quality amplifiers introduce distortion at higher power levels, which means the sound waves your speakers produce no longer accurately represent the source signal.
