FM vs DAB Car Radios: Key Differences

FM and DAB: what is the main difference?

The main difference between FM and DAB+ radio lies in the method by which the signal is transmitted: FM employs analog transmission, whereas DAB+ is a digital terrestrial radio system that carries both audio programs and data.

For car radio listeners, this technological difference translates into a distinct experience. DAB+ can offer a wider range of stations, easier tuning, additional services and information, and, when reception conditions are adequate, a digital listening experience free from the typical hiss of analog FM reception. DAB is designed not only to transmit digital audio but also data services intended for mobile, portable, and fixed reception.

However, this does not mean that FM radio has become obsolete or that DAB+ automatically ensures better reception everywhere. Service coverage, antenna, equipment quality, and reception conditions remain crucial, especially in a moving vehicle. Not surprisingly, specific technical requirements concerning the antenna and receiver system are defined for DAB+ automotive reception.

In Italy, FM and digital radio coexist: there is no planned general switch-off of FM broadcasts, and DAB+ complements analog radio, expanding listening options.

Therefore, to decide which technology is best for your car radio, it's important to look beyond a simple "analog versus digital" comparison and understand what really changes in terms of quality, coverage, available stations, and necessary equipment.

 

How does FM radio work?

FM radio transmits audio through an analog signal by modulating the frequency of a carrier wave: the car radio receives this signal via the antenna, tunes into the chosen frequency, and converts it back into audio.

FM stands for Frequency Modulation. In Italy, FM broadcasting uses the VHF II band, ranging from 87.5 to 108 MHz.

A recognizable feature of FM is how listeners choose a station: by frequency, for example, 98.5 MHz. However, during travel, the frequency used by the same broadcaster can vary across different geographical areas.

Modern car radios have made the experience more practical thanks to RDS (Radio Data System), technology that allows some digital information to accompany the FM broadcast. Depending on the broadcaster and receiver, the station name and other info can be displayed, and specific functions help the car tuner manage reception during travel.

The analog nature of FM becomes particularly evident when the signal weakens. Reception tends to degrade gradually, possibly causing hiss, interference, and quality loss; the station may still be audible even when listening is not optimal.

This behavior represents one of the most interesting differences compared to digital radio. With DAB+, not only the transmission of audio changes but also the way the system manages stations, data, and reception quality.

 

What are DAB and DAB+?

DAB means Digital Audio Broadcasting and is a standard for digital transmission of radio programs. DAB+ is its technological evolution, using a more efficient audio coding that better utilizes available transmission capacity.

The difference with FM stems from the very nature of the system. With DAB/DAB+, audio and information are transmitted as digital data, and multiple radio services can be organized within the same transmission block, commonly called a multiplex or ensemble.

The way drivers search for stations also changes. With a DAB+ car radio, it is unnecessary to remember the frequency: the receiver scans available services and presents them as a station list. The experience becomes closer to selecting content than manually tuning a frequency.

Are DAB and DAB+ the same?

No. DAB+ is an evolution of the original DAB, and the two standards use different audio coding technologies. Original DAB uses the MPEG Audio Layer II codec, while DAB+ adopts HE-AAC v2 and introduces more advanced error protection. Thanks to higher efficiency, DAB+ allows more effective use of the capacity within a multiplex.

When evaluating a new car tuner for digital radio reception today, it's important to explicitly check compatibility with DAB+ rather than stopping at the generic term "digital radio."

Does DAB+ transmit information beyond audio?

Yes. One of the advantages of digital radio is the ability to associate additional data and content with the radio program, which depends on the broadcaster and receiver.

On the display of a compatible car radio, textual and graphic information related to the transmission may appear depending on the service. Radio is no longer just a voice or song received from the antenna: it becomes a richer digital service.

To benefit, however, the entire chain must be adequate. It's not enough for the device to show the DAB+ logo: receiver and antenna system must ensure correct signal reception.

And here comes into play an often underestimated factor: the car DAB+ antenna. Its type, positioning, and proper installation can have an important role in the final result, which we will explore further later.

 

FM vs DAB+: what really changes while listening?

FM and DAB+ differ in transmission technology, behavior with weak signals, station selection methods, and amount of available information. However, this doesn't mean DAB+ is always better than FM everywhere: much depends on coverage and the car's reception system.

Here are the main differences:

Feature	FM Radio	DAB+ Radio
Transmission Type	Analog	Digital
Station Selection	Primarily by frequency	Via list of available services
Weak Signal	Quality tends to degrade gradually	Can maintain good quality up to a certain threshold, beyond which interruptions may occur
Listening Disturbances	Hiss and interference may appear	No progressive hiss typical of FM, but insufficient signal can cause audio interruptions
Additional Information	Available via RDS	Can transmit various data and content linked to the program
In-Car Reception	Requires adequate antenna system	Requires DAB+ receiver and suitable antenna system
Station Availability	Depends on broadcasters and FM coverage in the area	Depends on multiplexes and DAB+ coverage in the area

 

The difference is most noticeable when the signal worsens

This aspect is key to understand the analog versus digital comparison. With FM, moving away from a strong signal area, quality can deteriorate gradually: hiss and interference begin to appear, but the transmission may still be understandable.

Digital radio behaves differently. As long as the receiver has enough signal to correctly reconstruct data, listening can remain stable. But when reception falls below a threshold, errors and interruptions up to audio loss can occur.

Therefore, the shift from FM to DAB+ should not be seen simply as "more signal." It is a different way of receiving and managing the radio signal.

The way to choose what to listen to changes with DAB+

With FM, we are used to thinking in terms of frequencies: 90.1 MHz, 102.5 MHz, and so on.

With DAB+, the experience can be more immediate. The tuner scans receivable services and allows selecting stations from the list without the driver needing to know the transmission frequency.

On the road, this means less focus on tuning technicalities and more on what you want to listen to. Added to this is the possibility to receive program-associated information if broadcasted by the station and supported by the car radio.

The difference between FM and DAB+ is therefore not only about sound quality: it involves the whole in-car radio experience, from station search to reception management during travel.

 

Does DAB+ always sound better than FM?

No, DAB+ does not necessarily sound better than FM in every situation. Perceived quality depends on transmission quality, coverage, reception conditions, and installed car equipment.

One of the clearest advantages of digital radio is the absence of the typical hiss encountered when an FM station is poorly received. When the DAB+ signal is adequate, listening can be clean and stable even during travel.

However, this does not mean audio quality depends only on the digital nature of the signal. With DAB+, parameters like coding and bitrate chosen by the broadcaster also play a role. Consequently, two DAB+ stations may broadcast with different characteristics and thus offer different listening results.

Reception is also key. If the digital signal becomes insufficient, the progressive hiss typical of FM does not occur: instead, audio interruptions up to loss of transmission may appear. A good car DAB+ antenna, properly installed and compatible, thus becomes an important part of the system.

The rest of the audio chain matters too. Car radio, amplification, and speakers contribute to the final quality heard: switching from FM to DAB+ cannot automatically compensate for a poor audio system.

Rather than asking if DAB+ "always sounds better," it is more useful to consider what it truly offers: a digital way to listen to radio, with different reception behavior, more immediate station management, and access to additional services and info.

 

FM and DAB+ coverage: what happens when you travel?

Reception of FM and DAB+ can change during travel because both depend on coverage in the area. What changes most is how we perceive signal quality loss.

This is a familiar situation for many drivers: starting with perfect reception of a station, traveling tens of kilometers, and entering a new area where reception changes.

With FM the degradation can be progressive. Moving away from good coverage zones may bring hiss and interference, making listening difficult. RDS functions supported by the broadcaster and car tuner may also help manage the station during travel, for example through seeking alternative frequencies of the same broadcaster.

With DAB+, the experience is different. Multiple radio programs are transmitted within a multiplex and, as long as the received signal is sufficient, the system continues to reconstruct the digital stream correctly. When reception falls below the necessary threshold, audio may start to cut out until it disappears.

City, highway, or mountains: coverage is not the same everywhere

Buildings, terrain shape, infrastructure, and transmission network availability affect reception. For this reason, the same reception behavior can't be expected in a city center, on a highway, in a valley, or on a mountain road.

Tunnels are also a special case: the ability to keep receiving a station depends on dedicated retransmission infrastructure, not just on whether the car radio uses FM or DAB+.

Before blaming the car radio for constant interruptions, it is useful to check if the problem occurs consistently in the same areas. If reception worsens only in certain zones, coverage may be a primary factor. If the problem happens everywhere, even in normally well-covered areas, checking the vehicle's reception system is worthwhile.

This is where a crucial and often underestimated component comes in: the antenna. Having a car radio compatible with digital radio is only part of the system; proper antenna setup is essential for good DAB+ reception.

 

Is a dedicated antenna needed to listen to DAB+?

To properly receive DAB+ in a car, an antenna system compatible with digital radio frequencies is required. Having a DAB+ car radio alone does not guarantee good reception: antenna, connections, and installation must also be adequate.

This is often underestimated when upgrading an old car tuner to a newer model. While the radio may include a DAB+ receiver, the signal must still arrive at the device under the right conditions for decoding.

Different solutions can be used depending on the vehicle and setup, including dedicated DAB antennas or systems designed to handle multiple bands. There are also windshield-mounted antennas and amplified antennas, where integrated electronics require proper power supply to function as intended.

Antenna placement matters too

Especially for windshield antennas, the mounting point should not be chosen solely for aesthetics. Position, orientation, and installation method must follow the manufacturer's guidelines.

Windshield type and vehicle configuration may also influence the best solution. Therefore, before installing a new car DAB+ antenna, check product instructions and compatibility with the existing setup.

The same applies when reusing the vehicle's original antenna. Whether this is possible depends on the vehicle configuration and may require specific components: not all FM antennas are automatically suitable for DAB+ reception.

Poor DAB+ reception does not necessarily mean the car radio is faulty

If DAB+ suffers frequent interruptions, finds few stations, or performs worse than expected, the receiver is not the only element to check.

Before blaming the car radio, it is useful to verify:

• antenna type and compatibility
• correct placement
• connections between antenna and receiver
• power supply if an amplified antenna is used
• local DAB+ coverage

Digital radio is a chain: available signal, antenna, installation, and receiver must work together. Focusing only on the car radio while ignoring the antenna can limit system performance.

 

Can I add DAB+ to a car with only FM radio?

Yes, in many cases it is possible to add DAB+ reception to a car originally equipped with only FM radio. The best solution depends on the installed car radio, available inputs and connections, and the antenna setup.

One option is to replace the old car tuner with a car radio or multimedia system that includes a built-in DAB+ receiver. This is especially attractive when also updating other onboard functions, turning an outdated system into a more modern one.

In other cases, some devices may support digital radio via a compatible DAB+ module that connects separately. However, this capability must be explicitly provided by the manufacturer: having a USB port or other inputs doesn't automatically mean any DAB+ receiver can be added.

Whatever solution is chosen, the reception system remains crucial. If the car lacks a compatible system, installing a dedicated DAB+ antenna or a specific solution to use the vehicle's antenna, when technically feasible, may be necessary.

Before purchasing, it is advisable to verify three elements:

1. receiver compatibility, confirming it supports DAB+;
2. vehicle compatibility, especially when replacing the original radio;
3. antenna and accessories required, to avoid having a perfectly working digital receiver but a system unable to provide an adequate signal.

Upgrading a car originally equipped with only FM is often possible and can add new capabilities without changing vehicles. Technology becomes truly useful when properly integrated with existing onboard components.

 

FM or DAB+: which to choose?

If buying a new car radio today, the most versatile solution is one that supports both FM and DAB+. The two technologies can coexist and offer drivers more listening options depending on broadcasters and coverage.

DAB+ brings advantages of digital radio: quicker station selection, ability to receive additional information, and listening without the progressive hiss typical of weakening FM signals.

FM, on the other hand, continues to be a useful listening mode. Station availability and coverage vary by area, and especially during travel, being able to use both technologies means not depending on a single reception mode.

The choice should not be framed as FM versus DAB+ but as an evolution of in-car radio systems.

If considering a new tuner or multimedia system, consider at least these points:

• true support for DAB+ standard
• also includes FM receiver
• features and compatibility of the car DAB+ antenna
• necessary accessories for installation
• other functions desired in the onboard system

Updating is not just replacing an old radio but can enrich the car's multimedia experience.

 

More choice, more freedom on every trip

FM and DAB+ do not have to exclude each other: having both technologies onboard means choosing how and what to listen to based on the trip, area, and available stations.

This is the most interesting transformation. Radio, long associated with a frequency to remember, can today coexist with digital services, additional information, and more immediate station selection.

And you don't need a new car to enjoy it.

By properly updating car tuners, receivers, and antenna systems, even older vehicles can access digital radio while continuing to use traditional FM.

Technology becomes valuable onboard when it offers more freedom: departing, changing routes, crossing different areas, and always having more listening options.

With solutions from Macrom dedicated to car entertainment and radio reception, you can upgrade your multimedia system and add new features even to vehicles that did not originally have them.