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Surrounding
Yourself with Sound
You haven't experienced a movie until you hear it in
surround sound!
Up to the mid-50's, home audio was still the single channel mono format. The first multi-channel audio appeared in the 60's with stereo sound, a two-channel sound format making use of left and right front speakers. Stereo remained extremely popular up to the early 90's.
While stereo represented considerable improvement over monaural sound, yet it still lacked the ability to envelope the audience during movie watching or music listening.
In other words, it still lacked that surround sound field so important to help
the viewer get immersed into the movie action or experience the magic of a live
concert in the home.
The first surround sound playback systems appeared in 1982 with the advent of Dolby Surround. Dolby Surround is a 4-channel matrix-encoded format that continued to build on the successful two-channel stereo format by encoding the sounds for two extra channels, the front center and the rear surround - over the two stereo left and right channels.
It is the addition of this single rear surround channel, played over two identical speakers placed on either side of the listener, which made it possible for this format to surround the audience with sound.
In this guide to home theater surround sound, we start by explaining the different sound formats.
We then proceed by discussing home theater speakers and the different requirements associated with the various channel speakers in a multi-channel audio setup, correct speaker placement, and an explanation of speaker specs.
One cannot discuss home speakers and surround sound without looking at AV receivers and amplifiers; topics discussed include what makes a good amplifier and the rather controversial subject of amplifier power.
We conclude this series of articles with a few tips to enjoy better sound.
Multi-channel Surround Sound formats - Dolby, DTS, DVD-Audio, SACD - and THX
Multi-Channel Audio Formats:
Dolby Surround was to mark the first of a never ending list of home theater surround sound formats that soon followed in the process. Since then, the world of multi-channel surround audio got somewhat complicated. It is therefore more than understandable that many find it difficult to grasp the different surround sound formats in use today.
Luckily, some DVDs come with multiple sound formats, for example Dolby Digital and DTS on a single disc to ensure playback compatibility; furthermore, some standards are backward compatible.
Most surround sound formats incorporate a minimum of six discrete rather than matrix channels - meaning each channel is unique and independent of the rest. The increase in the number of audio channels helps re-create a more realistic sound stage. However, do not just opt for a 7.1 format if you have a small room; you would not be able to appreciate the benefits associated with the added channel speakers.
To help clear up the confusion surrounding multi-channel audio formats, we prepared a detailed guide that discusses the main characteristics of each of the different Dolby and DTS surround sound formats; formats covered include the latest high definition formats such as Dolby TrueHD and DTS-HD designed for use with high definition video on Blu-ray disc players.
In the process, we also discuss DVD-Audio and SACD - two popular multi-channel high-resolution audio formats designed for music listening.
THX:
Not a standard by itself, THX Home Cinema aims at delivering cinema-quality picture and sound to the home.
Many do not have an understanding of the THX certification system and related technology, or what the different labels found on home theater THX certified gear really mean. Yet to the 'everyday consumer', the 'THX' label signifies the highest standards have been used.
We are therefore presenting a short article that gives a brief overview of the THX certification program and related technology; in the process, we also see how THX relates to surround sound and home cinema in general.
Home Theater Speakers in Multi-Channel Audio
Surround Sound Speaker Systems Basics
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Before delving further into the topic of home theater speakers, we thought that it would be worth explaining a few basics about surround sound. Irrespective of the sound format in use, surround sound always rely on the use of dedicated speakers that literally and physically surround the audience. The number of surround speakers depends on both the number of playback channels supported by the selected audio setup and the sound format in question. |
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This leads to an added complexity with surround sound as the number of audio speakers in use does not necessarily match the number of audio signals supported by the surround format.
More information on surround sound basics follows here.
Home Theater Speaker Choice
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Without the correct speakers, you will never get the best out of even a premium $5,000 plus AV receiver such as the remarkable Denon AVR5308CI Reference-Level 7.1-Channel home theater receiver. The different audio channels in multi-channel surround sound impose different requirements on the respective audio speakers. As a result, shopping for home theater speakers can be particularly demanding. Unfortunately, many fail here. Admittedly, choosing the right speakers is possibly one of the toughest tasks faced by demanding home theater enthusiasts. |
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Klipsch Reference Series RF-83 |
But what complicates home speaker choice is not the large selection of home theater speakers or the expensive price tag associated with good quality home theater speakers.
Rather, it is the fact that human hearing varies from individual to individual' Thus, sound produced by a set of speakers is perceived differently by different listeners. And speaker specs would not tell you anything here.
But once you find the right set of good quality speakers for your liking, rest assured these will last for many years to come - much more than any other active system component in your home theater set-up.
You see, home speakers - like projection screens and home theater cables - form part of that category of technology that rarely gets outdated. If your speakers sound good within your room today, they will probably still sound good within the next 10 to 15 years. You will possibly be replacing your AV receiver and HDTV within this time frame - but not good quality speakers.
So... do not just buy the first set of home theater speakers you come across or try to save on your home theater expense by opting for cheaper speakers; the extra effort invested in speaker selection will more than pay for itself through an enjoyable sound experience in the many years to come.
What to look for when choosing a set of home theater speakers?
We discuss the requirements associated with each of the different surround sound speakers - front left and right speakers, center channel speakers, back and rear surround speakers, and the subwoofer - in our article 'Speakers for Multi-Channel Audio.'
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In the process, we explain the different speaker types that one may encounter in the home theater - from powered tower speakers and bookshelf speakers, to in-wall, ceiling speakers and dipole speakers. Shopping for audio speakers:There is more to a correct speaker choice in multi-channel surround sound than just having an understanding of the different requirements associated with the different channel speakers. |
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In particular, speaker matching is critical for a unified and more realistic soundfield.
Shopping for the best speakers is an art in itself; learning how to best shop for your home theater speakers as well as how to watch out for sales rep tricks when it comes to speaker listening tests during your speaker shopping process is essential for the best results.
We discuss the basics of how to shop around for the best speakers for a successful surround sound implementation in our article 'Shopping Tips for Home Theater Speakers.'
Speaker Placement
Choosing the correct speakers in a surround sound setup is important but it is not enough... you need to watch out on your speaker placement. Correct speaker placement plays a crucial role in any multi-channel audio, including stereo listening.
But in the case of multi-channel surround sound, speaker placement gets even more demanding to achieve a convincing soundstage. As we further explain in our article, 'Home Theater Speaker Placement', there are very specific speaker placement requirements associated with different multi-channel surround sound speaker setups to achieve a truly realistic listening experience. Not only, speaker placements vary also between music listening and movie watching.
More information is available here.
Understanding Speaker Specifications
Our discussion on home theater speakers would not be completed without explaining the different speaker specifications one would come across when selecting and buying audio speakers for a home theater set-up. Why?
There is no better way to avoid costly mistakes than to research your speakers before you buy. But you cannot do this without having an understanding at least of the most common speaker specifications in use today.
For an explanation of the different speaker specifications, please refer to our article 'Understanding Speaker Specs.'
What about Single-Speaker Surround Sound Systems?
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There are quite a number of single speaker surround systems such as the Polk Audio SurroundBar 50 surround system featured here that can do a fairly accurate job in creating an immersive soundstage. These single speaker surround sound solutions are normally adequate for people with very small rooms who for some reason, do not want either to get surrounded with speakers, or want to avoid the clutter and installation hassle associated with multiple speaker systems. |
While one may opt for a wireless speaker set-up to reduce the cable clutter for the surrounds and even for the subwoofer, a single speaker surround is much simpler to set-up than a hybrid wireless speaker solution.
Single speaker systems rely on virtual surround technologies - based on powerful digital signal processing techniques that can simulate the enveloping soundstage created by a 5.1-channel home theater surround sound loudspeaker system, over a two-speaker setup.
The Polk Soundbar 50 makes use of a Polk's proprietary SDA (Stereo Dimensional Array) technology in an attempt to simulate the effect of side and rear speakers. But there are others technologies as well and including the Dolby Virtual Speaker and SRS TruSurround.
Virtual surround technologies manipulate audio signals with sonic spatial cues by applying varying delays and phase-shifts between the different channels, based on extensive room-modeling technologies, to reproduce the sonic spectrum and dynamics of a properly placed 5.1 speaker system in a typical room environment.
But...
1] The expansive soundfield produced by single-speaker systems is limited to a rather restricted sweet spot.
2] Single speaker systems are best complemented by a compact powered subwoofer as their bass response is quite lacking. One such interesting option which can complement the Polk Audio Soundbar 50 featured above is the Polk Audio PSWi225 Wireless Subwoofer. Despite its compact 1 cu. ft design and 100W continuous power rating, the PSWi225 is capable of delivering exceptionally deep bass and the convenience of wireless connectivity.
3] While single speaker surround sound systems produce more than just an expansive soundfield, their performance comes nowhere close to that of a true multi-channel surround sound speaker setup. In other words, they provide the convenience of zero clutter at the expense of audio performance.
More information on virtual surround sound is available in our article 'Virtual Surround Technology.'
Amplifiers: Power, Sound Quality and Speaker
Loudness
 Onkyo TX-SR707 7.2-Channel A/V Surround Home Theater Receiver |
Like home theater speakers, AV receivers and power amplifiers are an integral part of a surround sound setup. It is not the scope of this series of articles to go into the details of AV receivers, but it is very important to have an understanding of what makes a good amplifier, whether that comes in the form of an AV receiver or a power amplifier. As we explain in our article 'Understanding Amplifier Specs', factors like amplifier power rating, distortion levels, amplifier dynamic headroom, and signal-to-noise ratio impact a power amplifier's ability to deliver adequate audio power and sound quality. |
Equally important is determining the amplifier power required to match your expected level of loudness. Amplifier power is a much debated issue and a grossly misunderstood term. In particular, many relate amplifier power directly with speaker loudness - which is not exactly the case.
Amplifier power has to be seen in the light of both your home theater speaker efficiency and the room environment. All three are equally important and need to be taken into account when planning a home theater audio set-up. For more information on amplifier power, please refer to our article here.
One final aspect we discuss under this section relates to AV receivers and multi-channel surround sound amplifiers settings, more specifically the issue of correct time delay setting in surround sound. Correctly set delay settings in surround sound playback systems can lead to dramatic improvements in your listening experience. More information of this subject is available in our article here.
Tips for Better Home Theater Sound
We conclude this series of home theater surround sound related articles by presenting our easy-to-follow tips to a better home theater sound.
Whether you are in the process of purchasing a new set of speakers or wish to make the best out of your present audio set-up, knowing what to do and how to setup your sound system to get a better sound is a basic step towards an enjoyable listening experience.
As we will show you in our article, in most cases it just takes a few inexpensive improvements to an existing home theater sound system to achieve a dramatic improvement in the audio quality of your surround sound.
In particular, achieving the correct sound balance between the different channels in a surround sound setup is a first essential step; you would need an inexpensive sound meter such as the Galaxy Audio CM130 SPL Meter, and a home theater calibration disc as further detailed in our Guide to Home Theater Calibration Discs here.
Home Theater Sound - Main Section Index:
Articles appearing under this section
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Surround Sound Formats Dolby Sound Systems are synonymous with surround. For many, Dolby is the king of surround sound, yet very few home users have a real understanding of the different Dolby audio formats available on most home theater receivers. Topics covered include:
DTS Surround Sound formats represent the second most popular lineup of surround formats available today. In this guide to DTS sound, we look at the different surround sound formats, from DTS Digital Surround to the latest DTS-HD audio solutions: High Definition Audio for Music Listening covering DVD-Audio and Super Audio CD (SACD) - including DualDisc and Hybrid SACD. Items discussed include:
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Home
Theater Speakers Home Theater Speaker Systems Basics: An introduction to multi-channel speaker systems. Speakers for Multi-Channel Audio: Discussing the requirements associated with each of the different surround sound speakers, as well as the type of speakers available - from floor-standing tower speakers to powered subwoofers and in-wall speakers. Home Theater Speaker Choice: Tips on how to shop for the best speakers for a successful surround sound implementation. Speaker Placement in Multi-Channel Audio: Correct home theater speaker placement plays a critical role towards achieving a seamless ‘enveloping’ sound so important in the overall home theater experience. Understanding Speaker Specs: Explaining the different terms associated with audio speakers. |
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AV Receivers and Amplifiers What makes good amplifiers - Understanding Amplifier Specs: Explaining how amplifier power rating, distortion levels, amplifier dynamic headroom, and signal-to-noise ratio impact a power amplifier's ability to deliver adequate audio power and sound quality. Amplifier Power: Matching the amplifier power output to your expected level of loudness is important both for an enjoyable listening experience as well as to avoid frying your speakers as a result of not enough amplifier power. Time Delay Setting in Surround Systems: Correctly set delay settings in surround sound playback systems can lead to dramatic improvements in your listening experience. |
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Additional Articles: Tips for Better Home Theater Sound: Often, all it takes are just a few inexpensive improvements to an existing home theater sound system to achieve a dramatic improvement in the quality of your surround sound. Dolby vs. DTS - Which is better? Many argue that DTS can deliver better sound than its Dolby counterpart. In this article, we discuss the differences between these surround sound formats to help you better understand why this Dolby vs. DTS controversy prevails. THX Home Cinema - An Overview: Many do not have a true understanding of what THX is all about. This short guide to THX Home Cinema explains this certification system, the different THX certification logos, and related technology; in the process, we show you how all this relate to surround sound and home theater. |
