To listen to music wirelessly with a hi-fi system or a home theater installation, the simplest solution is to use a Bluetooth connection. Most smartphones, tablets and laptops are equipped with an integrated Bluetooth transmitter. All you have to do is use the Bluetooth receiver built into the connected amplifier or wireless speakers that you want to use to play your music. Alternatively, you can invest in an external Bluetooth receiver, to be connected to one of the audio inputs of the hi-fi system or A/V receiver.
The second reason concerns the transmission quality of Bluetooth, which has been clearly progressing due to the apt-X protocol. If you have a computer fitted with an ?older generation’ Bluetooth controller, an apt-X compatible USB transmitter is very affordable (from 20 ?) and totally transforms your listening experience.
The advantages of a Bluetooth connection
Bluetooth: direct, simple and fast connection
The main advantage of Bluetooth is that it establishes a direct connection between the transmitter (smartphone, tablet, DAP, laptop) and the Bluetooth receiver in a few seconds. With Bluetooth, digital audio data does not pass through the WiFi home network and it is not necessary to know or enter a complex password.
The pairing process between the two devices is very simple and takes only a few moments. First, you have to put the receiver in “pairing” mode, then scan for the Bluetooth receiver with your computer, tablet, DAP or smartphone, before pairing them in a single step. When the two devices are NFC (Near Field Communication) compatible, you just have to bring them within a few centimeters of each other to pair them: it’s even easier.
The convenient pairing memory allows you to reconnect your devices very quickly the following times, without having to repeat the initial procedure.
Bluetooth: aptX HD and LDAC high resolution sound
Once criticized for the poor audio quality of its standard codec (SBC), Bluetooth now supports several audio codecs capable of wirelessly transmitting high-resolution audio streams.
Two formats are available to enjoy high-quality sound over Bluetooth: aptX HD (24-bit/48kHz), developed by Qualcomm, and LDAC (24-bit/96kHz) invented by Sony. These high-quality Bluetooth audio codecs are now supported by many smartphones and DAPs on the market.
If your computer is equipped with an older generation Bluetooth controller, you should know that an apt-X or apt-X HD Bluetooth transmitter significantly improves listening quality compared to first generation receivers with SBC audio compression.
Note: both the transmitter and the receiver must be compatible with the desired codec, be it apt-X, apt-X HD or LDAC. Otherwise, the (lower quality) SBC compression technology is used.
iPhone, iPod touch and iPad owners can enjoy the intermediate quality AAC codec, provided that the Bluetooth receiver supports it.
Bluetooth receivers
If your stereo system doesn’t have an integrated Bluetooth receiver, it is possible to use an external Bluetooth receiver. All external Bluetooth receivers, regardless of brand, are compatible with absolutely all hi-fi amplifiers, stereo systems and A/V receivers with analog (red and white connectors, RCA/cinch connector) or even digital S/PDIF inputs.
Bluetooth receivers with an analog output
Typically, entry-level Bluetooth receivers are fairly simple models, equipped with only a stereo analog output. It can be in RCA or mini-jack format, served by a modest quality output stage. This is the case, for example, of the Marmitek BoomBoom 75 and Marmitek BoomBoom 80 Bluetooth receivers, which are best paired with a stereo amplifier or a high-end hi-fi system equipped with an analog input.
High-fidelity Bluetooth receivers
For a more dynamic and spacious delivery of digital music, you should consider specialist hi-fi brands. For less than 100 euros, you can choose the NorStone BT Connector Hifi APTX receiver, which combines analog and digital connectivity. It also has the advantage of being able to be used as a Bluetooth transmitter. Useful for sending the sound of the TV to Bluetooth headphones, for example.
The Advance Acoustic WTX-500 is also a very effective Bluetooth receiver, to be connected directly to the RCA inputs of any integrated amplifier.
For more than 100 euros, there are audiophile Bluetooth receivers that are highly musical and optimized for high-fidelity listening. In addition to a high-performance aptX-compatible Bluetooth controller, they incorporate carefully selected electronic components, housed in interference-proof casings. Most of them are equipped with analog and digital outputs, like the Pro-ject Bluetooth Box S2 or the Musical Fidelity V90-BLU. Both of them ensure a transmission and reproduction quality well above the average, resulting in a truly hi-fi listening experience.
Bluetooth receiver and external DAC
A Bluetooth receiver with digital output can be used with an external DAC. This makes it possible to entrust the digital-to-analog audio conversion to a specialized device, which is often more efficient than the DAC built into the Bluetooth receiver. With such a configuration, the quality of the audio signal transmitted to the stereo hi-fi amplifier is much better.
With an A/V receiver, it is easier to use one of its digital inputs. The use of an external DAC does have any significant benefits in this case.
Bluetooth receiver: the importance of cables
We can’t stress it enough but it’s such a shame to invest in high quality electronics if you use them with poor quality cables. This only leads to disappointment.
The quality of the RCA and mini-jack cables is essential to enjoy a dynamic and balanced sound. The type of copper used and the geometry of the conductors, the shielding, the quality of the plugs and the soldering influence the transmission of the signal, and therefore the sound quality. Very often, the cables delivered with Bluetooth receivers are very basic and should be replaced by high-quality cables to enjoy a pleasant listening experience.
As for digital cables, even if you listen to music in MP3 format, you should know that the digital signal transmitted by the Bluetooth receiver to the external DAC or A/V receiver is converted into PCM signals with a bit rate equivalent to that of CD-Audio. A good quality optical or RCA coaxial cable is therefore highly recommended.
