Understanding Home Theater Speakers: Part 1

3d1I’m continually reminded of how those of us who consider ourselves home theater enthusiasts often forget that many of those around us don’t get into it like we do. Recently, I had a couple of non-enthusiasts remind me that they didn’t understand woofers and Blu-ray players. Which is great, because that’s the business I’m in: Teaching regular middle class people about confusing consumer tech.

Speakers are arguably the most important part of any home theater setup. They’re certainly where one should invest the bulk of one’s money. You’ll keep good speakers a lot longer than any other home theater gear, especially AV receivers, disc players, and streaming media boxes.

The following is an excerpt from my Kindle book Home Theater for the Internet Age. In the next blog post, we’ll discuss the all-important center channel (which carries the bulk of the spoken dialog of the actors in a TV show or movie) and the booming low-frequency subwoofer—thus rounding out the basic speaker positions in a six speaker, 5.1 home theater surround sound configuration.

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Curt Robbins


Dynamic Loudspeakers & Drivers

The most common type of speaker, from a technical perspective, is the dynamic loudspeaker. The term “speaker” can mean a few things, but is generally a reference to a single unit, in the form of a box-like enclosure, that contains one or more drivers. Drivers feature a cone (visible from the front of the speaker) made from a variety of materials—cheap ones being paperboard and nice ones being Kevlar or metal (typically aluminum or titanium). Behind the cone resides a mechanism involving a coil (sometimes called a voice coil) and a magnet. This coil, magnet, and cone-based driver is responsible for the extreme weight of good speakers (generally speaking, higher-quality speakers are heavier because they feature larger, more powerful magnets in their drivers).

Woofers & Tweeters

Dynamic loudspeakers feature the familiar and onomatopoeic woofer and tweeter combination, where the woofer carries the low and maybe some mid-range frequencies and the tweeter projects the high-end sounds. The most basic loudspeakers feature a single driver, whereas more sophisticated models include multiple woofers and midrange drivers, a powerful tweeter, and maybe even one or two acoustic resonance ports. Technically, with the exception of resonance ports, these are all “drivers,” or coil/magnet/cone devices capable of emitting sound. Thus, a speaker with a woofer, midrange, and tweeter has three drivers.

Form Factors

Each type of speaker that composes a full surround system plays a particular role in creating an immersive audio environment and dealing with particular types of sounds that are projected from specific areas of your room. These different roles manifest themselves in distinctly unique form factors, from the tall floor standing models flanking your display panel to the lone center channel that carries mostly movie dialog.

Floor Standing

Floor standing speakers, also called “mains” or “towers,” are typically the largest in your home theater and play a prominent role in delivering the impact of action movies and music. They carry the lion’s share of the sound in a surround mix, and are sometimes the only source of sound if you’re playing a stereo music CD (and don’t apply a special DSP field to turn it into artificial, or matrixed, surround).

Floor standing speakers are the bridge between the old world of “stereo systems” and the new world of surround sound. You’ll inevitably want to use your home theater to listen to music. If you’re really into music and, for example, you’re going to spend 50-80% of your time listening to it, and only the minority watching TV or movies, it makes sense to invest most of your speaker budget on the best towers possible. This may involve even going a bit downmarket for your rear speakers (but it’s highly advised that your three front speakers are from the same series). As you’ve learned, some people skip the subwoofer entirely so they can afford the best possible floor standing models while pursuing their dream stereo system.

Bookshelf / Surround

What are sometimes called “bookshelf” speakers (in a two-channel stereo configuration) are often labeled “surrounds” in a home theater. They’re basically junior models of the large floor standing models. They’re not necessarily lower quality; they simply feature less power and fewer drivers than their floor standing big brothers.

There are two options for the rear speakers in your surround system: Standard front-firing bookshelf speakers or dedicated multi-directional models. Dedicated surrounds create a more immersive effect. The design you choose depends on your personal tastes and room dynamics. Both good and bad examples of each approach are readily available. It’s more important to get a quality speaker with a wide frequency response and low distortion than to labor over the differences between these two designs.

You already know that you should purchase your surround speakers from the same series as your mains. Speakers from different series, and especially different manufacturers, can feature tonal discrepancies (different timbre) that will degrade the quality of your audio. A mismatched set also won’t look as nice sitting in your living room. That said, it’s sometimes better to have good speakers from different series than lousy units from the same line. Utilizing speakers from different series or manufacturers isn’t a cardinal sin and won’t necessarily produce bad sound; it’s simply not optimal.

If your home theater resides in a relatively small room or you’re on a tight budget, one option is to use robust bookshelf speakers for your mains also. While this may decrease your music listening pleasure (particularly at higher volumes), it will still sound good for movies if you purchase nice models, especially those that hit relatively low frequencies. Down the road, when you have the cash for proper floor standing mains, you can demote those front bookshelf speakers to center surrounds in a 7.1 system. (Often, the home theater of your dreams is not a matter of having a pile of cash to blow at one time, but rather being patient, planning intelligently, and building your system over years.)


Curt Robbins is author of the following books from Amazon Kindle:

You can follow him on Twitter at @CurtARobbins, read his AV-related blog posts at rAVe Publications, and view his photos on Flickr.

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Home Theater: Surround Sound Basics

3d1Today’s blog post continues our look at home theater, following yesterday’s Home Theater Basics. Below you’ll find an excerpt from my new book, Home Theater for the Internet Age, regarding surround sound. Most people understand that surround sound involves a speaker arrangement in your living room or dedicated home theater that “surrounds” you (duh).

This is a pretty radical departure from the common arrangement to which most of us (unless you’re a millennial) are acclimated: Sound that emanates from in front of us—typically from the display device, the TV, itself. The old method of projecting sound from the display was rife with deficiencies. First, the speakers built into even the best, most expensive, TVs suck. Period. There’s no physical room in a relatively thin panel for real speakers.

Modern home theater has introduced a more complex audio arrangement in which dedicated, much higher quality, speakers are positioned to the sides or even behind viewers. Because the sound is being projected from locations other than the display panel and is generated by real speakers, surround sound is the cornerstone of true home theater. However, because there’s so many types of surround sound arrangements, the topic can quickly become confusing for non-enthusiasts or those new to home entertainment.

Today we’ll address surround sound configurations. These are the physical layouts of speakers and the logical dispersion of audio channels from TV shows and movies. What’s 5.1? What do the “5” and the “1” mean? Why does your buddy at the office lust for 9.1? Read on to eliminate your confusion.

Also check out Home Theater: More Surround Sound and Home Theater: Surround Sound Formats.

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Curt Robbins


Surround Sound Configurations

As you’ve learned, there are several different physical configuration standards for surround sound, ranging from five to twelve speakers (and sometimes more). Arrangement shorthand is indicated by a decimal number, such as 5.1. This indicates five surround speakers and a single subwoofer. The number of subwoofers is always indicated to the right of the decimal (5.x). A 5.1 AV receiver is capable of outputting to a maximum of five speakers and a single subwoofer. A high-end 9.2 receiver, on the other hand, is capable of driving nine speakers and two subwoofers. If a friend says she has a 6.1 system, you know she has seven speakers total and that one of them is a sub. While uncommon, it’s possible that someone might have, for example, a 5.3 system, in which they have a basic surround complement and three subs (yes, some videophiles install multiple subwoofers).

You’ve already learned the basic role of a subwoofer, or “sub.” In surround sound, the sub carries the LFE, or Low Frequency Effects, channel. Most movies and some TV programming feature an LFE channel (identified as such on your AV receiver). Capable of emitting ultra-low frequencies below 80 Hz, subwoofers are as much about what you feel as what you hear. This low frequency speaker plays in the zone where sound goes from audible to tactile. If a movie indicates that it features “x.1 audio,” it means there’s a dedicated LFE channel (regardless of whether you have a subwoofer to bring this channel to wall-shaking life).

Typically, surround configurations range from 2.0 to 11.2. The most common config is 5.1 (although 2.1, while not providing any surround effect, is also very common). Try not to get surround envy. 9.1 and 11.1 systems are very rare and, arguably, complete overkill for the average consumer. Also, relatively few films and basically no TV shows are encoded in a standard above 7.1 (although this is rapidly changing). Thus, even if you had a fancy 9.1 system, a small percentage of the content you consumed would support it, making it a very expensive upgrade. (I have a 5.1 system and rarely lust for the two additional rear speakers of a 7.1 configuration. If I was going to upgrade, based on the size and layout of my living room, I’d probably never go beyond a 6.1 layout.)

It should be noted that all of these surround configurations are backward compatible, meaning that a 7.1 or 9.1 soundtrack will play just fine on a 5.1 system (or even a 2.0 system) or via headphones. That’s part of the magic of Dolby and DTS and modern home theater receivers.

2.1 & 5.1

Because this book defines home theater as having a minimum of five speakers, a 2.1 setup involving three speakers (two mains and a sub, with no rears) isn’t covered in detail. This type of configuration includes soundbars (see the Soundbars & Theater-in-a-Box section of the Speakers chapter for more info). While this setup doesn’t provide “surround” sound, it can—with even basic equipment—greatly enhance your time with music, TV, movies, and games. It will perform remarkably better than your TV speakers (those built into even high-end display panels are basically an afterthought, producing really crappy sound).

5.1 systems involve two mains (typically floor standing models, but sometimes bookshelf units), a center channel, two rear surrounds (called the left side surround and right side surround), and a subwoofer. Sometimes consumers opt to skip the subwoofer to save money (or because they underestimate the effect it will have during Blu-ray movies). Most videophiles consider 5.1 the entry-level setup for true home theater. If your AV receiver supports 7.1 speaker outputs, a 5.1 system gives you room to grow; simply purchase two additional speakers and you’re in business. While your front three speakers should always be from the same series to ensure timbre-matching, it’s less important for your rear and side surrounds to be from the same line (but still preferable for a variety of reasons).

6.1 & 7.1

Moving up the ladder, more complex surround configurations are 6.1 and 7.1. These involve one or two additional rear speakers, positioned directly behind the viewers, called the left back surround and right back surround—not to be confused with the left side surround and right side surround positions in a 5.1 or larger system. Should you go the extra mile and install one or two extra speakers between your existing surround positions? If you’re a big movie buff and your room is large enough to justify it, maybe. You won’t have trouble finding movies to fill this many speakers; most films today deliver a minimum of 7.1 surround audio channels (even some high-res music albums feature a 6.1 surround mix).

Remember that your AV receiver must support the number of speakers to which you want to expand. If you have a receiver capable of only 5.1, you’ll not only have to purchase one or two additional back surround speakers, but also a new receiver (as you’ve learned, this isn’t cheap, especially if the unit produces clean, robust amplification).

9.1 & 11.1

The average home theater owner probably shouldn’t pursue a 9.1 or larger surround sound configuration. However, it’s important to know one’s options. For very large rooms—or hyper-hobbyists who are pursuing the most realistically surrounding audio environment possible—one of the layouts involving more speakers than a 7.1 system might be appropriate. Of course, it will cost you. You’ll either have to increase your speaker budget or downgrade the quality of your candidates. Those additional speakers—especially if they match your other models—don’t come cheap.

A 9.1 system adds front height channels to the mix (the left height and right height positions), giving—as the name indicates—a taller and seemingly wider front soundstage than a 5.1 or 7.1 system can deliver. 9.1 is the first standard to address the expansion of the front soundstage (whereas 7.1 adds audio imaging to the rear area). Not only would you need to purchase additional speakers to satisfy the needs of a 9.1 system, but you’ll probably need to upgrade your AV receiver to handle the additional amps and terminals. And it hardly makes sense to upgrade without pursuing a few more watts or maybe going Class D. Cha ching.

An 11.1 system goes even further by adding left wide and right wide speakers, positioned at roughly 60 degrees from a forward-facing viewing position (to the left and right of the front height speakers, but closer to the central seating position). This setup results in seven front and four rear speakers. While relatively few movies have been released in 11.1, some of these leading edge films include Rise of the Guardians, Man of Steel, The Croods, Elysium, Turbo, Ender’s Game, Mr. Peabody & Sherman, and How to Train Your Dragon 2.


Curt Robbins is author of the following books from Amazon Kindle:

You can follow him on Twitter at @CurtRobbins, read his AV-related blog posts at rAVe Publications, and view his photos on Flickr.