How to choose your sound bar : Technologies, how to find your way ?

Sound bars have long been shunned by moviegoers and audiophiles, and with good reason. Not so long ago, these devices only reproduced the bad sound of television sets, but at a higher volume. That era is long gone, but now the conscientious buyer will need to study the choices offered to him because there are so many features available. There is a sound bar on the market for all types of uses such as surround sound cinema, immersive Atmos cinema and streaming sound from the web.

In this first article, I will share with you the technologies offered, followed by a few specialized articles by manufacturer such as Sonos, Samsung, Denon or Sony. Each of them has its own specialty.

2 Types of sound bars :

- With or without dedicated woofer (SUB)

Many soundbars work with a separate subwoofer, which may be included in the package or available as an option. Since a soundbar is still quite compact, bass performance will be compromised without it.

In most cases, the subwoofer will be wirelessly connected for easy placement.

For a smaller footprint, some soundbars offer a small built-in subwoofer in slightly larger units.

These will offer an acceptable sound. In this particular case, I strongly advise you to listen to them before buying, because techniques are evolving rapidly in the field of small format reproduction. Some will surprise you while others, less evolved, will not be worth the trouble.

More recently, we've seen bars with an "ultra thin" design. The ultra slim design is felt to fit perfectly on a wall mounted TV: you fix it to the wall and there goes the clutter! Adding a subwoofer is a must here...

Types of surround sound

Stereophony 2.0

As an ambience creation, the bare minimum will be stereophony with added depth effects. This approach is in the realm of cheap bars and offers the same thing as your TV, but louder. We'll call it 2.0 sound.

In order to obtain a better performance, especially for the voice track, we will talk about a 3.0 type sound which will consist in adding a third speaker in the middle of your bar to reproduce only the dialogues. 

If either of the above includes a subwoofer, a "1" will be added to its designation, i.e. 2.1 or 3.1 sound.

2D 5.1 or 7.1 surround sound

It will offer a rear to front ambience via rear sound boxes for the 5.1 and a combination of rear and side for the 7.1. You will have the choice between virtual or organic simulated effects. For the virtual effects, the use of reverberation on walls and ceilings will be the norm, while for an organic feel the use of additional rear and side boxes will be required. For sure, the realism offered by the extra speakers will be preferable despite their clutter.

- The soundtracks of this type include "Dolby digital" or "DTS Digital Surround".

3D surround sound 5.1.2 7.1.2 and more 

These are the bars that offer three-dimensional sound (Dolby Atmos or DTS: X), meaning that the sound comes from both the sides and the top. Vertical speakers are usually integrated into the sound bar and use the ceiling to reflect the sound back to the viewer. The best sets, such as the Samsung HW-Q990B, will have true back boxes with upward-firing components. The vertical component will be identified by a third number. For example, a 7.1.4 system such as the Samsung 990 will have four vertical channels.

 Types of diffusion of surround effects.

There are three ways to produce surround sound:

1 virtual surround sound.

This technique uses a digital interpretation circuit to create a resonance that gives the illusion of sound going around you. The degree of immersion experienced will depend on the effectiveness of this audio processing, but will be limited in any case. A busy environment will hurt the result.

2 Virtual surround by reflection.

 This will consist of speakers placed at different angles in the box as well as for the most sophisticated, of speakers directed towards your ceiling. They use the walls or the ceiling (for a 3D surround) to reflect the sound and give an enveloping sound. Since this time the sound is real and comes from real speakers, you will have a superior immersion performance.

3 true surround sound.

If you're looking for a truly immersive sound experience, you'll want to choose a model that includes a set of rear speakers. As with a full-size home theater system, having true 3D rear speakers aimed at the ceiling will provide maximum realism.

To realize the superiority of this approach and as an example, imagine a total silence while an airplane in the distance, in the background, approaches, only the rear speakers work on a real system, this work is impossible to achieve with a bar that uses the walls to recreate the rear field, even less achievable with a virtual effect, because in both cases, the rear sound will be generated by the front speakers...

It's interesting to know that many manufacturers offer optional rear speakers for their more affordable packages, so you can get "true surround sound" without having to buy the ultimate packages. The cost of this addition ranges from $200 to $350.

Criteria to consider

The power: it is expressed in watts, the more the better, because let's face it, when you watch a movie, you don't want to listen to lullabies!

200 watts would be a good start, ideally 400 watts including a value of 150 for a subwoofer would be preferable.

The number of speakers

There is no magic number, but the more there is, the more certain you are to get well defined effects. Three types of elements are offered such as the "woofer" for bass, the "mid" for midrange such as vocals and the "tweeter" for treble which is critical for sound field production and music rendering.

Complementary use: Music streaming.

Some models offer the possibility via a mobile application to access streaming music services. Thus, the best sound bars will turn into a competent sound system. Not silly when you think about it, because the TV, except for the rooms dedicated to this purpose, is often placed in a rest area of the household. In this case, pay attention to the features that affect the musicality of the set, including the use of high-level tweeter and the ability to play audio files of the type flac, dsd and other variants known for their realism and absence of losses (lossless).

To not be limited...

It is important to know the type of audio encoding for the widest choice of listening. There are encodings dedicated to cinema use and others for music listening.

CINEMA USE:

Dolby encoding

• Dolby digital : 5.1, = compressed sound available since 2000
• Dolby Digital Plus: 7.1, = with a higher bit rate offering a more natural sound
• Dolby True HD: 7.1, = high fidelity lossless audio compression
• Dolby Atmos: = three-dimensional sound (5.1.2, 9.1.4, etc.)

DTS encoding

• DTS Digital Surround: 5.1, = oldest compressed sound.
• DTS-HD High Resolution Audio: 7.1, = less compressed, more natural.
• DTS-HD Master Audio: 7.1, = high fidelity lossless audio compression.
• DTS : X : = 3D sound (5.1.2, 7.1.4, etc.)

USE OF MUSIC LISTENING :

Encoding:

• MP3 = Minimalist performance.
• AAC = CD quality.
• FLAC Hi-Rez = high-fidelity performance.
• DSD = studio quality (rarely offered on sound bars.

Wired connectivity type.

There are several ways to connect your sound bar to the TV. In the past, we used an RCA-type cable that only allowed stereophony with simulated ambience at best.

Subsequently, digital processing has allowed the transfer of the signal via fiber optic or S/PDIF and this remains the way to do it for both new and old TVs. The audio quality is excellent. It is possible to transmit multichannel sound, but the number of compatible formats is lower [no Dolby True HD or DTS HD Master Audio and so on].

 However, with the arrival of more and more devices connected via an HDMI cable [TV set-top box, game console, Blu-Ray player, Chromecast, etc.] the industry has developed a new bidirectional transmission protocol allowing the exchange of information in the transmission chain opening the door to an even more accurate performance. This protocol is called "eARC" and allows the transmission of all high resolution formats. Also appreciated is the possibility of volume control by a single remote control, that of the television set.

Type of wireless connectivity.

If you're lucky enough to have a TV that's 5 years old or younger, you'll probably be able to connect one of the new bars via Bluetooth. With Bluetooth, you'll get top-notch performance for everyday cinema listening. The high-flying cinema enthusiast will prefer HDMI cabling or the latest development, I call it WI-Fi connectivity! The two-way transmission speed of WI-Fi allows for precision and real-time audio patching. WI-FI also allows the transport of streaming music [Spotify Deezer and others] as well as voice control offered by Google and Alexa in particular.

Aesthetic consideration

In all of the products offered, there are great advances in aesthetics. The use of various shapes according to a squared or round theme as well as the addition of real fabrics will allow your acquisition to better blend into your decor.

The last word.

Here are the basics to get you started. In future articles, we will discover the difference between manufacturers for 2022. You'll know all about Sonos and its streaming approach without neglecting the wow factor in Dolby Atmos mode. Samsung on the other hand integrates the TV in a synergistic equation with the immersive Q-Symphony sound system. Sony for its part will favor high-fidelity musicality while Denon will offer a hybrid between the virtues of Sony and Sonos. So there's something for everyone! Absolutely!

Stay tuned!

• Christian.