What is surround sound?
Surround sound is a concept that encompasses a wide variety of formats that helps you to hear sound coming from multiple directions, depending on the source material.
Surround sound has been a vital part of the home theatre experience since the mid-1990s, and there are countless surround sound formats to choose from.
The Key Figures in the Surround Sound Sector
Dolby and DTS are the big guys in the surround sound landscape. Others, however, exist. Everyone keeps trying to make it better.
In fact, most home entertainment receiver makers have third-party partnerships with one or more companies that use their own twists to improve your surrounding experience, to ensure you have a pleasant experience.
What You’ll Need to Get Surround Sound
To experience surround sound, you must have a suitable home entertainment receiver that supports the following:
- At least a 5.1 channel speaker system.
- An AV processor matched with a multi-channel amplifier and speakers.
- A home-theater-in-a-box system or a soundbar.
Nevertheless, the number and type of speakers or soundbars in your arrangement are only one factor.
To take advantage of surround sound, you must access audio content that your home theatre receiver or another compatible device can decrypt.
Surround Sound Decoding
Surround sound can be made accessible through an encoding/decoding process. The copyright holder must mix, encode, and place the surround sound signal on any of the following:
- A disc
- Streamable audio file,
- The content provider using other types of transmission, such as a movie studio.
A fitted playback device like Ultra HD Blu-ray, Blu-ray, or DVD or media streamer must read an encoded surround sound signal like Roku Box, Amazon Fire, or Chromecast.
The encoded signal is sent from the player or streamer to a home theatre receiver, AV preamp processor, or another compatible device, which decodes it and distributes it to the proper channels and speakers so listeners can hear it.
Processing of Surround Sound
Surround sound processing is another way to get surround sound. This is markedly different from encoding/decoding.
Although you’ll need a home theatre, AV processor, or a soundbar to access it, no special encoding is required on the front end.
The home theatre receiver analyses sound waves to process surround sound. This wave can be analog or digital, searching for instilled signals that indicate where those sounds might be placed in an encrypted surround sound format.
Even though the results are not as precise as surround sound that implements an encoding/decoding system, it provides an adequate surround sound experience for most content.
Most surround sound processing formats can upmix any two-channel stereo signal to four, five, seven, or more channels. Many home theatre receivers and other compatible devices include the following surround sound processing formats:
- Dolby Pro-Logic: Up to four channels are plausible.
- Pro-Logic II: Up to five channels are possible.
- Pro-Logic IIx: Two-channel audio can be upmixed to seven channels, and 5.1 channel encoded signals can be upmixed to 7.1 channels.
- Dolby Surround upmixer: Upmixing from two, five, or seven channels to a Dolby Amos-like surround experience with two or more vertical channels is possible.
On the DTS side
- DTS Neo:6 (two or five channels can be upmixed to six channels)
- DTS Neo:X can upmix to 11.1 channels from two, five, or seven channels)
- DTS Neural:X (which works in the same way as the Dolby Atmos upmixer)
- Audyssey DSX: Adds an extra-wide channel, a front height channel, or both to a 5.1 channel decoded signal.
- Automatic by Auro3D Audio: It functions similarly to the Dolby Surround and DTS Neural:X upmixers.
In particular, concerning the surround, as mentioned earlier, sound decoding and processing formats, a few home theatre receivers, AV processors, and soundbar makers include Anthem Logic (Anthem AV) and Cinema DSP (Yamaha).
Virtual Surround
Although the above surround decoding and processing formats function well for systems with multiple speakers, soundbars require a different approach. This is where virtual surround sound enters the picture.
Virtual surround sound facilitates a soundbar or other system (often included as an alternative in a home theatre receiver) to provide surround sound listening with only two speakers (or two speakers and a subwoofer).
Virtual surround is not the same as true surround sound. It’s a group of technologies that use phase-shifting, sound delay, sound reflection, and other techniques to imitate actual surround sound.
Virtual surround can function in one of two ways. It can give a surround sound treatment to a two-channel signal. It can also take an incoming 5.1 channel signal, divide it into two channels, then use those signals to create a surround sound experience with the 2 different speakers.
Ambiance Enhancement
Surround sound can be improved further by integrating ambiance enhancement. Most home theatre receivers include supplemental sound enhancement settings that can add ambiance to surround sound listening, regardless of whether the source content is decoded or processed.
Ambiance enhancement has its origins in the use of reverb to imitate a larger listening area in the 1960s and 1970s (used extensively in-car audio), but it can be irksome.
Reverb is implemented through the sound or listening modes found on many home theatre receivers and AV processors.
The modes enhance the ambiance cues for specific content types or simulate the acoustic properties of particular room environments.
Listening modes may be provided for movie, music, game, or sports content. Sometimes, it becomes more specific (sci-fi movies, adventure movies, jazz, rock, and more).
Some home theatre receivers also have options for simulating the acoustics of different room environments, such as a movie theatre, auditorium, arena, or church.
A final feature available on some high-end home theatre receivers is the ability to manually customize the pre-set listening mode and ambiance configurations to provide a better outcome by tweaking variables like the room size, delay, liveness, and reverb time.
Conclusion
Surround sound has become an essential part of the theatre experience for moviegoers everywhere. Putting together the surrounding mix has become a critical step in the production process for filmmakers.
Surround sound has effectively expanded movies into three dimensions, putting the audience in the middle of the action.
Getting a sound system or a soundbar with a subwoofer can be the first step to achieving true immersive home entertainment.
