home theatre 101
What you need to know to achieve the best cinematic experience
Home Theatre has been around longer than you may think. It began back in the 1920s and 1930s when Hollywood’s elite built screening rooms so they could watch movies they had just produced, directed, or starred in. Even though they were luxurious, early home theatres were complex and intimidating. The moguls who enjoyed them kept technicians on staff to run the noisy and cantankerous projectors of the day. Technology has come a long way since. Now, home theatre systems are far more convenient, far more accessible, and far more reliable. And, thanks to the efforts of literally thousands of engineers, designers, and installers, they’re far more capable, too. A good home theatre system will provide hours of enjoyment for you and your family as it literally immerses you in sights and sounds once available only at the finest first-run movie houses. A home theatre system can also help create just the right environment in which to enjoy your favorite movies by adjusting lighting, closing the drapes, even turning on the popcorn machine! For the music lover, a home theatre system can also do double duty and reproduce your favorite music recordings with startling clarity.
Consider what kind of a home theatre system you really want. It might be a full-scale dedicated theatre room with custom seating, lights that dim automatically when you press “Play”, curtains that sweep into place to block distracting sunlight, an extensive loudspeaker array, and the latest super high-resolution front projector; in other words, the kind of system that can provide a fully immersive sensory experience. Or perhaps you would like a simple solution that you can hook up yourself in an hour or so and yet will still offer much improved performance over the speakers built into the TV.
If you’re like most people, you’re probably aiming at something between these extremes. That means a component system – one composed of separate yet complementary sources like a Blu-ray DVD player, a cable or satellite box for broadcast television, a streaming video source, all connected to a surround processor or a capable A/V receiver.
We’ve chosen to limit our offerings to just a few really outstanding audio/video components – price point based products may seem to offer everything, but unfortunately something must give as the price drops. That “something” is the most important thing of all – sound quality! Paper specs can be fudged to the point where they are close to meaningless (and frequently are). The simple truth is sound critical stages are cost intensive and we just won’t skimp there. Our attitude may seem uncompromising… because it is! Your home theatre is likely to be the center of your home entertainment for years. As you consider an investment in a new home theatre, we encourage you to think in those terms. Day in and day out, it will either disappoint or delight you. Our all-in-one receiver, the RSX-1562 rivals most separate components. Our RSP surround processor models, when combined with our multi-channel theater amplifiers, offer a level of immersive cinematic sound that will take movie watching to a new level of involvement.
Whether you choose a Rotel receiver or an RSP and an array of amplifiers, we recommend you discuss the installation services offered by all Rotel dealers. They understand room acoustics, system matching and the multitude of details that can make the installation of a home theatre a gratifying experience from start to finish, leaving you only needing to make some popcorn and push play!
THE TYPICAL HOME THEATRE
While there is no such thing as a ‘standard’ home theatre, we can generally break up the system into a few key categories, which we will cover in greater detail below.
A relatively standard home theatre setup might consist of a few sources such as a Blu-Ray player and Cable TV set top box, a TV, a Surround Receiver such as the RSX-1562, 5 speakers and an Active Subwoofer.
What does “5.1” and “7.1” mean?
This term is used quite frequently in Home Theatre, so we’ll discuss it briefly here.
The first number is used to indicate the number of full range channels of audio in the system (full range meaning the full range of audio frequencies, from high treble frequencies to low bass frequencies). So in a 5.1 system this would represent:
2 front speakers
1 center channel speaker
2 side surround speakers
A 7.1 system would include the same 5 channels as the 5.1 system, plus an additional 2 rear surround speakers.
The second number represents the Low Frequency Effects (LFE) channel, which is another word for the subwoofer channel. This channel is dedicated to purely bass frequencies below 120Hz, although there might be plenty of bass directed to the main speakers, too. The LFE channel is designed to provide that extra “boom” when the movie requires it.
A typical 5.1 or 7.1 system would include the 5 or 7 full range speakers, plus one (or more) subwoofers for the LFE channel.
Home Theatre Sources
The source material for your Home Theatre can come from a wide variety of places. However, it is good to keep in mind what types of sources you plan on using to ensure your system has all the appropriate connections to handle them.
Some of the most common sources are listed below.
- Offers excellent high-definition video and sound quality and sound in a disc format. Blu-ray players are also backwards compatible to DVDs and CDs, and sometimes support other more esoteric disc formats like SACD.
- What you need to play it – A Blu-Ray player.
- The disc format that preceded Blu-ray and is still widely used. Offers good video quality and sound, but not at the same quality level as Blu-Ray.
- What you need to play it – A DVD Player.
CABLE OR SATELLITE TV
- Most broadcasts now offer HD video as well as high quality digital audio.
- What you need to play it – A cable or satellite set top box.
- There are a large variety of different streaming services available, both with standard and high definition video.
- What you need to play it – A streaming video player such as AppleTV, Roku or a “smart” TV with streaming services built in. Many Blu-ray players, smart TVs and game consoles also support streaming services.
What sort of display will you be using to watch your movies? Will it be a dedicated theatre with an overhead projector and film screen? Or is this your living room with a 60” LED TV? Do you need 3D? Choosing the right display to show your video is another critical step in the process, and requires careful consideration. At the time of this writing, almost every current display will utilize the HDMI connection to display the video. Your choice will be influenced by a variety of factors, from décor to ambient light levels.
While choosing the right display is certainly important, there are many resources to help you decide the best fit for your system, not the least of which is your local Rotel dealer.
Most Home Theatre systems will stick to a 5.1 or 7.1 channel arrangement, although there certainly are systems that utilize far more than this number of speakers.
Let’s stick with 7.1 for now and quickly summarize the roles of each speaker:
Front – your main speakers, these will typically be the workhorses of the system, producing most of the sound effects and some dialogue that occurs on screen during a movie.
Center – the center channel speaker’s primary role is dialogue, and the speaker is usually placed directly below or above the display to anchor the sound to the screen.
Surrounds – these two speakers handle ambient sounds or effects that are intended to be around the listener.
Center Back Surrounds – these two speakers provide a more precise portrayal of sounds that move from front to back of the sonic landscape, such as flyovers.
Subwoofer – The subwoofer is used to deliver much of the impact and “thump” from the system, so if you really want to feel the sound as much as hear it don’t skimp here!
Speaker Placement Guidelines
Here are some broad guidelines for home theatre loudspeaker placement. These recommendations are not cast in stone, as almost every system and every room has some eccentricity that requires a bit of modification. However, if you stray too far from these guidelines, you will probably create more problems than you’ll solve.
These speakers should flank the display and subtend an angle of 45 degrees when viewed from the main viewing/listening position. Most loudspeakers sound best when placed away from the front and side walls of the home theatre room. Make every effort to place both speakers on the same plane. This means they should be at the same height as each other, preferably with their tweeters at ear level when you’re seated in the prime location. They should also be placed at the same distance from that prime viewing/listening location.
The center channel speaker must be as close to the TV screen as possible. Of course, different display types may require different approaches to get the best placement. Here are some suggestions.
Place the center channel speaker so that its tweeter is at the same height as the left and right channel tweeters. Ideally, all three tweeters will be at seated ear level. If your room doesn’t allow for this ideal placement (and many won’t), place the center channel speaker immediately below (preferred) or above the display’s vertical centerline. Make sure you choose the location (above or below) that places the tweeter closest to an imaginary line drawn between the tweeters of left and right main speakers. Make sure you “aim” the center channel speaker at the seated ear level of the primary viewing/listening position.
In general, place the main surround speakers well above ear level on the side walls. They should be slightly behind the main listening/viewing position and above ear level so that the speakers’ radiation patterns avoid excessive localization, which can prove distracting while watching a movie. Avoid aiming directional surround speakers directly into the prime listening/viewing area. In some cases, bouncing surround information off a rear wall before it reaches the ears of those in the audience might be advisable.
Center Back Surrounds
Mount the additional rear surround speakers high on the rear wall at approximately one-third intervals. Thus, the left rear surround speaker should be placed about one-third of the way across the wall from the left corner, while the right rear surround speaker will be best placed about one-third of the way across the wall from the right corner.
When setting up your home theatre, proper bass management is a key step to making sure your system sounds as good as it possibly can. Not every loudspeaker is designed to be able to reproduce deep bass frequencies. It can take a fairly large speaker and woofer to really hit the low notes effectively, and asking a small bookshelf speaker to try and reproduce some of the more demanding bass effects on a movie soundtrack can sometimes result in distortion or even damage to the speaker if it isn’t designed to handle those frequencies. Fortunately, most home theatre receivers and surround processors offer some settings to allow you to specify whether your speakers should be played as “Large” full range speakers, which can handle deep bass signals, or if they should be designated as “Small” speakers which will have their deep bass signals rerouted to the subwoofer. This way you can let your smaller speakers play the way they were intended while letting the subwoofer handle the heavy lifting which it was designed for.
Every loudspeaker has its own sonic characteristics that are determined by things like the materials used to construct the speaker, as well as the actual design of the speaker. The overall sound of the speaker is sometimes referred to as its “color” or “timbre”. When considering speakers for a home theater, another factor that should be considered is “timbre matching”. That is, you want all of the speakers in your system to sound more or less the same, so that when a sound effect pans across different speakers there is not a noticeable change in the sound. For example, if in a movie track a car were to drive across the screen the sound might originate in the left front speaker, transition to the center channel then exit from the right front speaker. Ideally, the sound should appear consistent across each speaker. For this reason it tends to be preferable when choosing a speaker system to stick with the same manufacturer and speaker series when possible, as this will ensure a matched sounding system from all channels.
The Electronics - The Surround Processor and Power Amplifier
Once you have your source material and selected speakers, you will need some electronics to connect everything up. The heart of a typical home theatre system can be broken up into two distinct sections – the surround processor and the power amplifier.
The surround processor acts as the control system for the entire theatre. The processors role is to allow you to switch between all of your various sources, and for each source the processor can decode the audio, provide volume control, bass management and route the decoded sound out to the power amplifiers and subwoofer. In many cases the processor also switches and routes the video signals to the display as well.
When choosing a processor, there are many factors to consider, one of the foremost being connectivity: can I connect up everything I want to listen to in my theatre? Most video sources today utilize the HDMI connection to pass both HD audio and video, so having enough HDMI connections is always important. However, you may have other sources to consider. For example, want to listen to some music on your iPod? A front USB connection will allow for this. Perhaps you have a Sonos Connect that you want to use to stream music to the system – an optical or coax digital connection would be ideal for this. Do you need 3D video? Make sure the processor can pass 3D video via HDMI.
After the surround processor is the power amplifier. The power amplifier has one job – to take the relatively low level audio signal from the surround processor, amplify it and send it along to the loudspeakers where it is produced as sound. While this seems simple enough, doing it well and with minimal distortion is what separates the poorly designed amplifiers from the quality ones. A well designed amplifier should be able to reproduce all the subtle nuances of a quiet passage of the movie soundtrack, then in the next instant be able to replicate all the slam and impact of a massive explosion or action scene without missing a beat.
In a typical home theatre each speaker should have one channel of amplification (there can be cases where a speaker uses more than one channel of amplification such as bi-amping, but that is beyond the scope of this article). So for a “standard” 5.1 home theatre that consists of 5 loudspeakers plus an active subwoofer you would need a 5 channel amplifier.
You will want to ensure that the continuous power output of your power amplifier is matched up or exceeds the recommended power handling specification of the speakers you will be using the amplifier with. This will ensure that your speakers are receiving the appropriate amount of power they need to operate. A poorly matched system can result in damage to the amplifier or speakers, so it is important to make sure your amplifier and speakers are appropriately matched. Also make sure the loudspeaker impedance is within the capabilities of the amplifier – the lower the impedance of the speaker, the more difficult it is to power.
Separates vs. a Receiver
When a surround processor and power amplifier are combined into one component it is called a surround Audio/Video receiver (AVR for short). An AVR can offer a cost savings, but at lower performance that you can get with a separate surround processor and amplifier. Some of the reasons for this are bill-of-materials cost, as manufacturers have to make compromises to keep the receiver at a certain price point, as well as simple physical limitations – it can get very tricky to design and lay out a complete circuit design that incorporates the surround processing, power supply and 5 to 7 amplifier channels, as well as any other features like a tuner or USB audio circuits, all within one chassis. It is much harder in an all-in-one AVR to make sure the audio signal path isn’t corrupted by noise from tightly packed circuits. That said, a well-designed AVR can be be a great compromise, offering excellent performance in a convenient single component.
Stepping up to separate components can yield many benefits, not the least of which is the ability for the design engineers to optimize the circuit designs without having to fit everything into one chassis. Another benefit is each component will have its own power supply, rather than having the processor and amplifier share the same power supply. The last major benefit is that you can upgrade in stages. The surround processor tends to be more prone to technical obsolescence than an amplifier.
Using Your Home Theatre for Music
Just because a system is considered a Home Theatre system doesn’t mean it can’t also pull double duty as a great music system. Our Home Theatre power amplifiers have more than enough finesse to reproduce all the nuances of demanding musical passages without missing a beat. Likewise, our Surround Processors and Receivers offer many features geared toward music performance such as a dedicated analogue bypass option should you wish to listen to your music in stereo with no additional processing, as well as front and rear USB connections for playing your digital music sources.
With a component system you can find the performance typical of the finest custom-installed theatres. From the sublime to the ridiculous, your theatre system can be limited only your imagination. Whatever your comfort zone, be sure to contact one of our highly skilled professional dealers for a demonstration that will knock your socks off! They know and understand all about sound and can confidently install a system designed specifically for your family.