Has it ever happened to you that you buy a new TV, a home theater system, or an AV receiver and you are like a child with new shoes? Then you take the technical specifications book and it falls to your feet. You have before you an alphabet soup full of acronyms of audio and video codecs that there is nowhere to get it. You look at the sky and entrust yourself to divine providence. And it is no wonder: video definitions (4K, 1080p, HDR) or surrounds sound formats (Dolby, DTS, Atmos, Auro 3D…) bring most mortals down the street from bitterness. And it is important to know their differences and how we can use our new devices to get the most out of them. Therefore, we have prepared this help manual for dummies with all the specifications that you should know when handling or purchasing a home theater system.
What is surround sound in home cinema?
In 1982, Dolby Labs introduced Dolby Surround to the market. It allowed surround sound to be emitted through a process known as Matrix decoding. Matrix? Easy Tiger. This term has nothing to do with the red or blue pill.
So what about the matrix? It refers to the decoding of different audio signals within a stereo source. This technology was the foundation for many surround sound formats to come to light and we currently have many surround sound options for use with a home theater system. Here are the main ones ordered chronologically:
Dolby Pro Logic
Dolby used the Matrix system with Pro Logic to achieve surround sound by decoding separate signals from the left and right channels of home stereos. This made it possible to reproduce sound with two extra channels with the old VHS videotapes. Surround sound in the Pro Logic format had limited bandwidth and each surround speaker reproduced the same sound.
What is Dolby Digital 5.1? And the DTS format?
With the advent of laserdiscs (LD), both the amount of sound information in recordings and their quality increased. Taking advantage of this new technology, Dolby created the AC-3 format, now known as Dolby Digital. It sure sounds familiar. This format improved the performance of Pro Logic since it allowed the use of stereo surround speakers that provided better bandwidth. It also added a dedicated channel for bass frequencies (the “.1” for 5.1 home cinema systems) driven by a subwoofer.
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This format was the one used by most home theater systems for a long time, even when DVDs began to appear in 1997. Today, the Dolby Digital 5.1 format remains one of the most popular surround sound codecs. It is the first format to provide independent audio information for each speaker, a guideline followed by the most popular surround back codecs.
Dolby dominated the surround sound market until DTS (Digital Theater Systems) appeared in 1993. Did you know that the first time this format appeared in theaters was with the movie Jurassic Park? Later this technology began to be integrated into DVDs as well. The DTS format uses a higher bandwidth than Dolby Digital, so it provides more audio information. The difference in quality between DTS and Dolby Digital, however, is hardly noticeable.
Dolby Digital Plus, Dolby TrueHD, DTS-HD and DTS-Master HD
The Home Cinema 7.1 systems were introduced with the arrival of HD-DVD and Blu-ray discs. With these came new formats of Dolby and DTS that can take advantage of the greater memory capacity of these discs.
Dolby offers two formats designed to work with Home Cinema 7.1: Dolby Digital Plus, which works with compressed audio files that take up less space; and Dolby TrueHD, an uncompressed version. DTS also has two options: DTS-HD, which works with compressed files; and Dolby TrueHD, for files without compression.
Not all Blu-ray discs offer 7.1 surround sound mixes, as they are very heavy. On the other hand, a 5.1 mix can be used by a 7.1 home theater system through the AV receiver, although the two extra surround speakers will not output different sounds.
Pro Logic II, Pro Logic IIx, and Pro Logic IIz
If you have or have been looking to purchase a new AV receiver, you will find that they have several Pro-Logic format options: Pro Logic II, Pro Logic IIx, and Pro Logic IIz.
Pro Logic II can create surround sound for 5.1 Home Cinema systems from a stereo source. It is perfect for use with movies or TV shows that feature a stereo mix. Pro Logic IIx is a format that can take 5.1 surround sound mixes and expand them to 6.1 or 7.1 systems. On the other hand, the Pro Logic IIz allows you to add two speakers that are located above the center speaker and between the front side speakers with which a greater depth of surround sound is obtained compared to the other versions.
Object-based surround sound codecs
The latest and most complex surround sound codecs ( Dolby Atmos, DTS: X, and Auro-3D ) create a new sensation of sonic three-dimensionality not present in older formats. They are known as “object-based” systems since the mixture of these formats allows representing of sound objects in a 3D space, where each object, or information package, contains independent audio information.
What is Dolby Atmos?
Dolby Atmos is the most popular among these new formats today. The Atmos can process up to 128 different audio objects in one scene. Atmos surround sound, for example, can make the sound of an explosion emitted from different points, achieving a unique 3D effect thanks to the use of additional ceiling speakers. This codec began to be used in theaters with Pixar’s Brave movie and has been available for quality AV receivers since 2015.
What is the DTS: X codec?
DTS also has its own version of the object-based codec: DTS: X. While Dolby Atmos supports 128 objects per scene, DTS: X has no limits. It’s more flexible than the Atmos, as it doesn’t need ceiling speakers, and it can support up to 32 surround speakers in a home theater system. It is newer and less popular than Atmos, but the best AV receiver companies are integrating this format into their new equipment.
Auro-3D is not as well known as Dolby Atmos or DTS: X but it has been around for a longer time. This technology has been in theaters since 2006, but only recently are companies like Marantz and Denon offering this format for their most comprehensive AV receivers. Auro-3D does not technically work with object-based systems, but it performs very similarly. It offers good surround sound, although it requires additional speakers. It is used with large home theater systems, such as the 9.1 or 11.1.
Video in home cinema systems
If we buy a quality TV or AV receiver, there are several aspects, when it comes to video, that we have to take into account so that our purchasers can be adequate for several years. The capabilities for 4K resolution, HDCP 2.2, HDMI 2.0, and HDR are the main ones to look for. Below we briefly explain what these acronyms refer to:
What is 4K (Ultra HD)?
Full HD resolution (1920p x 1080p) has been the most widely used high-definition format for several years, but new televisions and AV receivers are already capable of playing movies with higher quality: 4K, or Ultra HD.
The terms 4K and Ultra HD are interchangeable. They both point to a resolution of 3,840 x 2,160 pixels. This is slightly less than 4K digital cinemas (4,096 x 2,160 pixels) but means a four-fold increase in HD definition.
Today there are few shows or movies available to enjoy this definition, but we believe that 4K will undoubtedly be the standard for high definition within a few years. If you are thinking of buying a new TV or AV receiver, we recommend that you bring it included.
What is HDMI 2.0?
The HDMI 2.0 ports are a specification linked to 4K resolution that we must take into account for our home cinema systems. 4K resolution requires higher bandwidth to transmit than HD resolution (it contains much more information). To support the new resolution optimally, the HDMI 2.0 port has been created. P eremite 2160p video transfer up to 60 frames per second. The above HDMI ports can transmit 4K video but not 60 frames per second. The higher transfer speed of the HDMI 2.0 port is also necessary to play 4K movies or series from services such as Netflix.
What is HDCP 2.2?
The acronym HDCP 2.2 ( High-Bandwidth Digital Content ) refers to a new content protection standard available on new Blu-ray discs. The HDCP 2.2 system can prevent new 4K movies from being captured by an illegal recorder by generating encrypted keys between the TV and the Blu-ray player. In order to enjoy a movie with this type of encryption, our televisions and AV receivers must be HDCP 2.2 compliant.
Lastly, we want to mention HDR ( High Dynamic Range ). HDR is a video format that is already available on the latest high-end televisions. It has the same resolution as 4K video but adds additional color and brightness data. HDR video, in formats such as HDR10 or Dolby Vision, is more eye-catching and sharper than normal high-definition videos. In order to enjoy HDR video, you need your TV and AV receiver to be compatible with this technology.
In this article, we briefly explain the most important specifications that you should consider if you want to buy a new AV receiver or TV.
Hope this article helped you to gather knowledge about Audio and Video Codecs. If you have question, leave them below.