AVIXA Recognized AV Technologist Test

Which audio signal has a nominal level of 1 volt?

1. Microphone level

2. Loudspeaker level

3. Professional line level

4. Consumer line level

The correct answer is: Professional line level

The audio signal that has a nominal level of 1 volt is the professional line level. In audio engineering, different signal levels correspond to varying equipment and usage scenarios. Professional line level, which is typically set at a nominal level of +4 dBu, translates to approximately 1.23 volts. This allows for a stronger signal that can be used for broadcasting and high-quality audio applications, minimizing noise and interference during transmission. In contrast, consumer line level is generally around -10 dBV, which is about 0.316 volts, and is designed for home audio equipment. Microphone level signals are much weaker, usually operating in the range of -60 to -40 dBV, while loudspeaker level signals are higher still, often in the range of tens of volts, depending on the amplifier power and speaker design. Understanding these distinctions is crucial for correctly matching equipment and ensuring optimal audio signal integrity in various setups.