The loud popping noise and vibrations that occur when you turn up the volume on an amplifier can be attributed to a few different factors:
Sudden increase in power: When you increase the volume on an amplifier, you are increasing the power being sent to the speakers. This sudden surge of power can cause a transient signal spike, resulting in a popping sound. The speakers' diaphragms may also move abruptly, leading to vibrations.
DC offset or turn-on thump: In some cases, amplifiers may have a DC offset, which is a small voltage difference between the output terminals. When the amplifier is turned on or the volume is increased, this DC offset can cause a thumping sound. This sound is more noticeable if the speakers are not properly protected or if the amplifier circuitry has design issues.
Speaker protection circuits: Many modern amplifiers incorporate speaker protection circuits to prevent damage to the speakers. These circuits often introduce a delay or a soft start mechanism when the amplifier is powered on or when the volume is increased rapidly. This delay can cause a popping sound or a brief period of silence before the audio is heard.
It's worth noting that excessive or persistent popping noises and vibrations could indicate a problem with the amplifier or speaker system. If you encounter such issues, it's recommended to consult the user manual or seek assistance from a professional audio technician to diagnose and resolve any potential issues.