Bluetooth has meanwhile become the standard when it comes to directly connecting mobile or portable devices wirelessly. Thanks to Bluetooth, computers, smartphones, and tablets as well as peripheral devices like keyboards and mice communicate wirelessly – and audio signals are also transmitted via Bluetooth to speakers and headphones. There are, however, differences between various Bluetooth devices. Below, we explain why this wireless standard holds such a dominant position and what innovations exist in the world of Bluetooth.
The Bluetooth project: one standard for all manufacturers
No question: audio cables and USB cables have their place. But sometimes they’re simply annoying. Luckily, there’s Bluetooth! This wireless standard connects devices such as PCs, keyboards, smartphones, headphones, or speakers over short distances – regardless of the manufacturer. We owe this interoperability to the Bluetooth Special Interest Group (SIG), which drove the development of this wireless technology in the late 1990s. Founding members of the SIG included Ericsson, IBM, Intel, Nokia, and Toshiba. Today, the interest group includes more than 34,000 companies. This makes Bluetooth, alongside Wi-Fi, the most important wireless standard.
The name “Bluetooth” is a tribute to the Danish king Harald Bluetooth, who in the 10th century also managed to unite the rival kingdoms of Denmark and Norway through skillful diplomacy. His initials (HB) can be seen as ancient Nordic runes in the Bluetooth logo. The naming was influenced by the key involvement of the Swedish manufacturer Ericsson.
What are the advantages of Bluetooth?
A Bluetooth wireless connection is characterized above all by high stability, a comparatively high transmission speed, and low energy consumption. In addition – unlike infrared, for example – no line of sight between devices is required; similar to Wi-Fi, transmission even works through walls. However, Bluetooth is primarily limited to the short range, especially for audio data. For this purpose, though, the wireless standard is ideally suited.
Reading tip: You can find out when audio streaming via Wi-Fi or Bluetooth makes sense elsewhere on our blog.
Unlike Wi-Fi, no additional network device (router) is required to connect two devices via Bluetooth. It’s enough for both the Bluetooth transmitter and receiver to be present. This makes the wireless connection direct and easy to establish.
Opens in new tabHow far the Bluetooth signal reaches depends, among other things, on the design of the respective devices and the specific environment. With the Low Energy profile of Bluetooth 5 , purely theoretical ranges of up to 200 meters are possible. For audio streams, the range is usually reduced to around 10 meters due to the significantly larger data volume. Obstacles such as walls significantly affect the range of radio waves regardless of the application.
The range also depends on which class the respective Bluetooth device belongs to. There are three different ones: Class 1 with 100 mW transmission power, Class 2 with 25 mW, and Class 3 with 1 mW. The more compact the device, the lower the power – and therefore the class – tends to be. Bluetooth headphones usually belong to Class 2, with a range of about 10 meters. Notebooks and other devices with higher transmission power are assigned to Class 1.
Bluetooth was developed as an energy-efficient wireless standard. Therefore, power consumption increases only minimally with an active Bluetooth connection. Tests with smartphones from different manufacturers have shown that the wireless connection accounts for only a very small share of battery consumption. So there’s hardly any benefit to switching off Bluetooth to save power.
The Bluetooth ROCKSTER from Teufel
The advantages of Bluetooth for audio streaming
That Bluetooth and audio streaming are a great match is confirmed by anyone who has ever connected their smartphone to headphones or a wireless speaker via Bluetooth. Since increasingly better audio compression options have become available, sound quality has also improved: anyone transmitting audio data wirelessly no longer has to compromise on sound quality. This is mainly thanks to the aptX® codec.
With Bluetooth headphones, not only are tangled cables and broken wires a thing of the past, they also offer a completely new level of freedom of movement compared to wired models – for example when jogging with headphones.
Bluetooth headphones receive their audio signals via wireless data transmission. To enjoy all the benefits of a wireless connection between the headphones and the audio source (e.g. smartphone, notebook, hi-fi system), it’s best if both sides communicate using the same Bluetooth standard. Also note that audio transmission often works in only one direction, usually to the Bluetooth headphones as receivers. You can also learn on our blog how to connect Bluetooth headphones to your TV.
Bluetooth radiation is not dangerous. Conventional Bluetooth devices emit only very low levels of electromagnetic radiation, which are well below the prescribed limit values. Here we explain why Bluetooth headphones are not unhealthy.
Opens in new tabBluetooth profiles and audio compression
Different Bluetooth profiles are used depending on the application. A printer, for example, requires a different profile than a cordless phone. Audio data is also transmitted using its own profile, known as A2DP (Advanced Audio Distribution Profile). A2DP specifies a standard codec for audio transmission: the Low Complexity Subband Codec, or SBC for short. MP3 or AACOpens in new tab would also be possible, but SBC transmission requires less processing power and is more universal, although it is not particularly efficient.
SBC typically uses a bitrate of up to 345 Kbit/s. As it is a lossy compression method, this can result in a loss of quality depending on the nature of the source data, which was a major argument against Bluetooth transmission for audiophile listeners for a long time. With the aptX® codec, however, Bluetooth has also become interesting for Hi-Fi enthusiasts.
What Is Bluetooth aptX®?
The aptX® audio codec uses a compression method that results in significantly less data loss. It was developed back in the 1980s and 1990s and was primarily used for ISDN telephony to ensure better voice quality. For Bluetooth audio, aptX® enables data transmission rates of 352 Kbit/s, while aptX® HD can reach up to 576 Kbit/s. This also makes Bluetooth aptX®Opens in new tab interesting for Hi-Res streaming. According to its owner Qualcomm, aptX® enables transmission in near-CD quality. For aptX® to work, both the transmitter and receiver must support the codec.
Bluetooth keeps evolving
Since the first version of Bluetooth was introduced in 1999, the standard has continued to evolve. Bluetooth Classic started with a gross data rate of 1 Mbit/s. Enhanced Data Rate later added 2 or 3 Mbit/s, depending on the modulation. With Bluetooth Low Energy, Bluetooth 5 primarily introduced the optional 2M PHY with speeds of up to 2 Mbit/s, as well as LE Coded for greater range at lower data rates. The often-cited benefits of Bluetooth 5 – double the speed and up to four times the range – therefore mainly apply to Bluetooth Low Energy and do not automatically apply to every audio connection. For music streaming, the codec, device, environment and distance are more important than the Bluetooth version number alone.
Bluetooth 5.0
The Bluetooth 5.0 standard was announced back in 2016, but it only actually became available in 2020. Compared with its predecessor, version 4.2, it brings several improvements and new features. In particular, work has been done to improve range, speed and power consumption. The Low Energy variant is also new.
What is Bluetooth low energy?
Bluetooth Low Energy (LE for short) is a low-power version of the wireless standard that allows devices within a range of 10 meters to connect. Its key advantages include very fast connection setup and energy-efficient data transfer. LE is primarily used for the Internet of Things (IoT), smart home devices and wearables. Unlike other Bluetooth standards, LE is not backward compatible.
In theory, Bluetooth 5 allows a transmission power of up to 100 mW. However, as this comes with increased power consumption, this feature is less attractive for mobile devices. If the transmission rate is reduced to 500 or 125 Kbit/s, however, ranges of up to 200 metres outdoors and up to 40 metres indoors are possible.
What range do devices with Bluetooth 5 have?
Ultimately, this depends on the chip and device manufacturers. The maximum range of 200 metres is, importantly, a theoretical figure. Comparable ranges can only be achieved with Bluetooth 5 for low-energy IoT applications. With data-intensive audio streams, Bluetooth 5 does offer better connection stability, but ranges significantly beyond 10 metres are not possible.
Bluetooth beacons for precise data transfer
Bluetooth beacons are small radio transmitters that can send data to Bluetooth 5-enabled devices without the conventional pairing process. The transmitters can pinpoint the receiving device and initiate the transmission. They can send data to multiple receivers within range without establishing a direct connection. This was also possible before Bluetooth 5, but older versions were limited to 31 bytes per packet.
By increasing the amount of data to 279 bytes, this technology is set to play a more important role. For example, navigation services can be established in large buildings such as airports, government offices or universities. People with visual impairments could use their smartphones to receive assistance with navigation. This functionality is also interesting for marketing services in shops.
Bluetooth 5.1 – Direction finding
The version 5.1, which has also been available since 2020, is an extension of the 5.0 standard. What is new in this version is the so-called Direction Finding feature. This makes it possible to determine the direction and distance of other devices that also support Bluetooth 5.1. This is not only useful if you can’t find your headphones, but also opens up many new possibilities for automation, for example in logistics.
Bluetooth 5.2 – New developments in audio
The Bluetooth LE Audio profile was developed, among other things, for Bluetooth 5.2. It enables more energy-efficient audio transmission. With LE Audio, for example, multiple headphones can be connected to a single audio source. This feature has a wide range of applications: several people could, for example, watch the same film on a train using headphones. It is also interesting for silent discos. Other notable features include:
- Broadcast Audio: Audio streams can also be sent to more than two receivers simultaneously.
- New standard codec: LC3 (Low Complexity Communications Codec) replaces SBC as the standard codec. This allows for higher transmission quality.
This also makes the wireless standard more attractive for wireless home cinemaOpens in new tab. Perhaps you’ll soon be able to operate your entire surround sound system without any audio cables!
Further reading: Want to connect your Bluetooth headphones to your TV? Our guide with video tutorial can help.Opens in new tab
Is lossless transmission possible with Bluetooth?
Standard Bluetooth audio using SBC, AAC or aptX is lossy: the audio signal is compressed for wireless transmission. Truly lossless transmission is only possible with suitable codecs such as aptX Lossless – and only if the source, receiving device and connection all support it. aptX Lossless can transmit CD quality at 16-bit / 44.1 kHz bit-perfect. If the wireless connection is poor, the codec reduces the bitrate to prevent dropouts.
For Hi-Res Audio at 24-bit / 96 kHz, Bluetooth codecs still use lossy compression. If you want to be sure you’re listening to truly lossless audio, Wi-Fi streaming or a wired connection is more reliable.
Why does audio sometimes sound quieter over HDMI than over Bluetooth?
This impression often arises because it’s not just the connection itself, but above all the source and its signal processing that determine perceived volume. TVs often transmit a signal with greater dynamic range via HDMI ARC or eARC, while smartphones, streaming apps or operating systems frequently adjust loudness or reduce the dynamic range. As a result, Bluetooth can sound louder subjectively, even though the actual level is not higher.
In addition, the HDMI, Bluetooth and analogue inputs of an audio system may be calibrated differently, meaning that individual sources can sound louder or quieter at the same volume setting. The claim that HDMI is generally quieter than Bluetooth is therefore not technically correct. What matters is the source, its signal processing and the way the devices involved are calibrated – not the HDMI connection itself.
Bluetooth 5.3 – Improvements for smart devices
Version 5.3 brought improvements for IoT devices and wearables. These include a more stable and faster connection as well as slightly longer battery life. This can also make a difference with headphones.
Bluetooth 6.0 to 6.3 – More precise positioning and more efficient connections
Development continued after Bluetooth 5.3: with Bluetooth 6.0, the focus shifted in particular to so-called Channel Sounding. This allows compatible devices to determine distances more accurately. This is particularly interesting for digital keys, trackers, smart home devices and applications where devices need to determine whether another device is actually nearby.
Bluetooth 6.1 primarily brought improvements in privacy and energy efficiency. Devices can update their Bluetooth address randomly at shorter intervals, making tracking more difficult while also reducing the load on the controller.
Bluetooth 6.2 and 6.3 introduced further refinements, including shorter connection intervals, improvements to Channel Sounding, increased capacity in the Host Controller Interface and more efficient radio architectures.
Add Bluetooth to your setup with an adapter
If you want to transmit audio from a TV or PC to Bluetooth headphones, you need a Bluetooth transmitter. With the REAL BLUE PRO + FeinTech BT200 Bluetooth Audio TransmitterOpens in new tab, you get the transmitter and premium over-ear headphones together in one bundle. The BT200 transmits the audio wirelessly to the REAL BLUE PRO. Both devices support aptX Adaptive. The transmitter can also provide audio to up to two Bluetooth headphones simultaneously.
Teufel’s portfolio of Bluetooth devices is growing
Teufel offers a wide range of Bluetooth-enabled devices, including Bluetooth speakersOpens in new tab and Bluetooth headphonesOpens in new tab. These can be quickly connected to a smartphone, laptop or tablet, allowing you to enjoy your music without any cables getting in the way.
▶ The REAL BLUE PROOpens in new tab is Teufel’s all-rounder among over-ear headphones. Bluetooth 5.0 with aptX®, Active Noise Cancelling and a Linear HD driver with plenty of bass deliver maximum listening enjoyment, even in noisy environments. And if you do need a wired connection, no problem: the headphones also feature a 3.5 mm jack. For wireless TV, film and gaming audio, the REAL BLUE PRO is also available in a bundle with the FeinTech BT200 Bluetooth Audio TransmitterOpens in new tab.
▶ If you prefer something more discreet, the REAL BLUE TWS 3Opens in new tab in-ear headphones are the perfect choice. They give you complete freedom of movement in any situation. Despite their compact size, the REAL BLUE TWS 3 deliver powerful sound thanks to Bluetooth 5.3.
More Bluetooth products from Teufel
REAL BLUE NC 3 + FeinTech Bluetooth Audio System
189,99 €
MYND
199,99 €
ROCKSTER CROSS 2
299,99 €What to do if you have Bluetooth problems?
The wireless standard offers plenty of possibilities for audio. But what if Bluetooth doesn’t work? Connection problems can have various causes. The most important thing is that the devices you want to pair support the feature and the respective audio profile. Even so, conflicts and interference can still occur. You’ll also find useful tips for troubleshooting Bluetooth on the Teufel BlogOpens in new tab.
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