Microphone vs Loudspeaker: Key Differences Explained

This page compares a microphone and a loudspeaker, highlighting the differences between these two crucial audio devices used to serve human needs.

• A Microphone converts acoustical sound energy into electrical energy.
• A Loudspeaker converts electrical energy into acoustical sound energy.

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Microphone

A microphone is essentially an instrument designed to convert sound waves into equivalent electrical waves.

The input is acoustic waves, and the output is taken using two electrical wires. Various types of microphones exist, each with unique constructions and operational principles, as explained below.

Crystal Microphone

In this type of microphone, electrical signals are produced by applying variable pressure developed by sound waves on a pair of surfaces of a quartz crystal. It operates based on the piezoelectric effect and is often preferred in sound recording systems.

• A lips microphone is a crystal microphone used in front of a speaker’s mouth.
• A cardioid microphone is a crystal microphone used on a speaker’s neck or chest.

Carbon Microphone

A carbon microphone consists of two metal plates separated by carbon granules. One of the plates is thin and faces the speaker, acting as a diaphragm.

When sound waves impact the diaphragm, it vibrates, creating varying pressure on the carbon granules. This changes the electrical resistance between the two plates, causing the output electrical current to vary accordingly. Carbon microphones are commonly used in public address systems.

Dynamic and Ribbon Microphones

These microphones operate based on Faraday’s laws of electromagnetic induction. A dynamic microphone is also known as a moving coil microphone.

Capacitor Microphone

The charging and discharging currents of a capacitor are converted into AC signals by varying the capacitor’s capacity using sound waves.

Wireless Microphone

These microphones utilize wireless technologies like Bluetooth. They are also known as Bluetooth microphones or Bluetooth mics.

Carbon, dynamic, crystal, and capacitor microphone types are unidirectional microphones, often referred to as pressure-operated microphones. The ribbon microphone is a velocity-operated microphone, allowing sound to enter from either of its two sides.

Loudspeaker or Speaker

A speaker takes an electrical signal as input and translates it back into physical vibrations to create sound waves. It’s considered an electromechanical device used in numerous applications, such as hearing aids, air raid sirens, and public address systems.

There are two main types of loudspeakers:

• Moving coil type
• Electrostatic type
• Ribbon type

Loudspeakers can be wired or wireless (i.e., Bluetooth), depending on their connection with the transmission medium.

Loudspeakers are often used with enclosures to reduce free-cone problems related to cancellation and resonance. These enclosures prevent sound waves emitted from the rear from mixing with those emitted from the front. Without enclosures, the 180-degree out-of-phase component of the rear waveform can cancel the front waveform component, an effect more prevalent at low frequencies.

Difference Between Microphone and Loudspeaker or Speaker

Here are the major differences between microphones and loudspeakers:

• Conversion: A microphone converts sound to an electrical signal, whereas a loudspeaker converts an electrical signal to sound waves.
• Usage: A microphone is used at the transmitting end, while a loudspeaker or speaker is used at the receiving end.
• Proximity (Mouth/Ears): A microphone should be close to the mouth, whereas a speaker should be close to the ears for better performance.
• Proximity (Speaker/Listeners): A microphone should be close to the speaker, whereas a speaker doesn’t need to be close to the listeners.
• Size: Microphones are generally smaller in size compared to loudspeakers or speakers.