Final answer:
To ensure an audio system is equalized, besides an SPL meter and signal generator, an oscilloscope is needed to display the characteristics of sound being produced by the speaker, allowing for adjustments in amplitude and frequency.
Step-by-step explanation:
When testing the audio system to ensure that the system is equalized, in addition to an SPL (Sound Pressure Level) meter and a signal generator, one would typically need an oscilloscope. This setup involves using a function generator connected to a speaker to produce sounds of different frequencies and amplitudes. A microphone, then connected to the oscilloscope, can display the characteristics of the sounds produced.
The function generator allows you to control the loudness and frequency of the sound being produced by the speaker, with controls for amplitude and frequency. The microphone picks up the sound and converts it to an electrical signal, which is then displayed on the oscilloscope. This allows for experimentation with different amplitudes and frequencies, helping to understand the impact these changes have on the waveform.
The most common oscilloscope controls include amplitude, frequency, triggering, and channels. With the guidance of a teacher or a professional, you can acquire a signal using the correct channel and triggering, then use the amplitude and frequency controls to visually interpret the sound characteristics.