Understanding how speakers work and why they are the key component in most audio systems

How does this work? Clear audio streams are processed by digital processing equipment, amplified by advanced power amplifiers, and finally delivered to listeners through cone-shaped paper diaphragms in wooden speaker cabinets.

The weak link in this chain is the speaker, commonly referred to as a loudspeaker. The final sound quality of any system depends entirely on the speaker's ability to reproduce the excellent audio provided by the upstream components.

Over the past century, commercial speakers have undergone a long and steady evolution. In contrast, the electronic components of the system have undergone fundamental changes in both physical properties and research methods at an extremely rapid pace.

However, the fact that the transducer (speaker) has not kept pace with the corresponding electronic components does not mean that everything has lost its meaning.  

On the contrary, even today's designs cannot achieve the astonishing performance people desire. Understanding how speakers work and why the speaker enclosure is the key component in most audio systems  

What components are inside a speaker?

The task of a speaker is to convert the electronic signals from an audio system into sound energy that humans can perceive. In most cases, the closer the output is to the input, the better the result (i.e., high fidelity).  

It is also important to understand that no matter how excellent the speaker is, an input source that does not meet standards will always degrade sound quality.

Professional speakers typically include multiple units (components) within a single enclosure. The most common design is referred to as a “two-way system,” where two components work together to produce the output.

A two-way system typically includes a 15-inch or 12-inch diameter cone-shaped woofer, a small (1 to 1.5-inch) tweeter, and a horn that provides a specified coverage angle.

Here's an overview of the typical components of a two-way speaker: in a wooden enclosure or the increasingly common polymer composite enclosure, there are the driver on the horn, the crossover, and the cone-shaped woofer.

For the woofer, which reproduces low frequencies, the enclosure provides a flat surface to directly radiate the output into the surrounding environment.

Conversely, if the high frequencies processed by the driver are directly sent to the coverage area, they are barely audible. Therefore, the driver must be matched with a horn to extend the sound waves from the driver into the surrounding environment at the specified frequency and dispersion angle.

As a result, the installation of the horn/driver significantly improves efficiency, requiring only a few watts of input to provide sufficient loudness for the entire room.

Inside the speaker, the input signal is distributed to two drivers via a passive crossover network, commonly referred to as a crossover, which directly assigns low frequencies to the bass driver and high frequencies to the treble driver.