2. Sound Sources & Signal Paths

At the heart of any acoustic performance is the sound source itself. That means a sound, a voice, or a musical instrument. In most cases, such a sound source needs to be amplified so that the audience can understand it.

A pleasant side effect is that during the signal processing, we can also balance out large volume differences between the sound sources from the beginning, like from a trumpet to a guitar or drums and vocals. Plus, we can spice things up with additional sound effects.

To achieve this signal amplification, you need a complete sound reinforcement system or a "PA system."

The signal path of a typical small PA system

If we look at the path a signal takes from the sound transducer (for example, a microphone) to the output (the speakers), it can be simplified as follows:

Sound Transduction:
First, the acoustic sound is converted into an electrical signal or voltage. This task is handled by the microphone.

Preamplification, Processing, and Mixing:
In the mixing console, the incoming signals are pre-amplified and blended. Additionally, they can be equalized (EQ) to correct their tonal quality and, if needed, enriched with effects.

Power Amplification:
The signal coming from the mixing console needs to be significantly amplified so that it can drive a speaker. This job falls to a power amplifier (or an end stage). The power amplifier can be integrated into the mixing console (eg. powered mixers), exist as a standalone unit (power amplifier), or be part of a speaker enclosure (active speaker).

Sound (Re)transduction:
Finally, the amplified (still electrical) signal is converted back into an acoustic signal. This task is performed by one or more speakers.

Signal Cabling:
The various components are connected with cables. Depending on the type of signal, you'll use either signal cables or speaker cables. But more on that later.