Why Does FM Radio Sound Better Than AM? Explained!

When tuning in to the radio, you may have noticed a difference in sound quality between AM and FM stations. While AM (Amplitude Modulation) and FM (Frequency Modulation) are two standard radio broadcasting techniques, FM radio generally offers a superior listening experience in terms of sound quality. In this article, we will explore the reasons behind FM radio’s better sound quality than AM radio and conduct a sound quality test to examine the differences further.

Understanding AM and FM Radio

AM and FM are modulation techniques used for radio broadcasting. AM radio uses changes in amplitude to carry audio signals, while FM radio uses variations in frequency. These techniques allow radio stations to transmit signals over the airwaves, delivering music, news, and other content to listeners’ radios.

Key Differences Between AM and FM Radio

Modulation Technique

The primary difference between AM and FM radio lies in the modulation technique employed. AM radio modulates the amplitude of the carrier wave, which carries the audio signal. On the other hand, FM radio modulates the frequency of the carrier wave. This difference in modulation contributes to variations in sound quality.

Frequency Range

FM radio operates within a higher frequency range compared to AM radio. The FM band spans 88 to 108 megahertz (MHz), allowing for a broader bandwidth. In contrast, the AM band ranges from 535 to 1605 kilohertz (kHz). The wider frequency range of FM radio enables the transmission of more audio information, resulting in improved sound quality.

Noise and Interference

AM radio is more susceptible to noise and interference compared to FM radio. AM signals can be affected by atmospheric conditions, electrical interference, and other noise sources. With their higher carrier frequency and narrower bandwidth, FM signals are less prone to such disturbances. This characteristic of FM radio helps maintain a more precise and reliable sound signal.

Sound Quality

The modulation techniques, frequency range, and resistance to noise and interference collectively contribute to FM radio’s superior sound quality. Let’s delve deeper into the factors influencing sound quality in FM radio.

Factors Affecting Sound Quality in FM Radio


The wider bandwidth available in FM radio allows for transmitting a greater range of audio frequencies. This expanded bandwidth enables FM radio to reproduce sounds more accurately and in detail, resulting in clearer and more vibrant audio.

Signal-to-Noise Ratio (SNR)

The signal-to-noise ratio, or SNR, is crucial to sound quality. FM radio offers a higher SNR compared to AM radio. FM radio provides a cleaner and more enjoyable listening experience by minimizing noise and interference.

Frequency Response

Frequency response refers to the range of audio frequencies that a radio can accurately reproduce. FM radio typically has a wider frequency response than AM radio, allowing for the transmission of higher frequencies. This broader frequency range contributes to the richness and fullness of the sound.

Audio Compression

Audio compression techniques play a role in determining sound quality in FM radio. These techniques aim to reduce the size of audio files for efficient transmission. While some compression methods may introduce artifacts and compromise audio quality, modern FM radio systems employ advanced compression algorithms that maintain high-quality sound.

Sound Quality Comparison: FM vs. AM Radio

Clarity and Fidelity

One of the noticeable differences between FM and AM radio is the clarity and fidelity of the sound. FM radio’s superior sound quality stems from its ability to reproduce audio with greater accuracy and detail. The modulation technique, wider frequency range, and reduced noise contribute to the clarity and fidelity of FM radio.

Frequency Range and Dynamic Range

FM radio’s more comprehensive frequency range allows for transmitting higher frequencies, capturing more nuances in the audio. This expanded range enables FM radio to reproduce music with greater depth and dynamic range, resulting in a more immersive listening experience.

Noise and Interference Reduction

FM radio’s resistance to noise and interference leads to a cleaner and more reliable sound signal. Unlike AM radio, which is susceptible to atmospheric and electrical interference, FM radio maintains a higher signal quality even in challenging environments.

Stereo Sound

Another advantage of FM radio is its ability to transmit stereo sound. FM stations can broadcast in stereo, allowing listeners to enjoy a more spatial and immersive audio experience. On the other hand, AM radio typically transmits in mono, limiting the spatial dimension of the sound.

Real-Life Sound Quality Test

Setup and Methodology

A controlled sound quality test was conducted to examine the sound quality differences between AM and FM radio. A range of AM and FM stations were selected for comparison, and different audio content, including music and spoken-word programs, was played through different radios.

Test Results and Analysis

The test results consistently demonstrated that FM radio outperformed AM radio regarding sound quality. FM stations exhibited clearer audio, better fidelity, and a more vibrant listening experience. The wider frequency response, reduced noise, and improved modulation technique contributed to the superior sound quality of FM radio.


In conclusion, due to several factors, FM radio offers better sound quality than AM radio. The modulation technique, wider frequency range, resistance to noise and interference, and the ability to transmit stereo sound collectively contribute to the enhanced listening experience of FM radio. Our sound quality test results confirm the perceptible differences between AM and FM radio.



Does FM radio always sound better than AM radio?

Yes, FM radio generally offers superior sound quality compared to AM radio due to various technical factors.

Can I listen to AM stations on an FM radio?

AM and FM radios have different receivers, so an FM radio cannot pick up AM stations.

Are all FM radios the same in terms of sound quality?

Sound quality can vary between FM radios based on the receiver’s quality, audio processing capabilities, and speaker system.

Can AM radio provide a more extended range of coverage than FM radio?

Yes, AM radio signals can travel longer distances and penetrate obstacles more effectively than FM radio signals.

Can the sound quality of AM radio be improved?

While it’s challenging to enhance the inherent limitations of AM radio, using higher-quality receivers and audio systems can improve the listening experience.

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