Get Your Hair Blown Back: All About Speakers for Your Home

Remember that famous advertisement for Maxell cassette tapes -- the guy sitting in his armchair getting his hair blown back by the sound from his stereo speakers? This classic image is often mentioned by our clients to describe what they'd like their new sound system to deliver (or at least be capable of delivering).

Although flat-panel video displays are all the rage, quality sound is still critical for a true "home theater" experience. But what's involved?

Power Up

First, a speaker needs amplification (or at least most do -- some are self-powered). But how much power? The subject can get very technical, and long, but here's a brief overview.

The classic "watts per channel" (WPC) rating is often used, but taken in isolation it is of little value. Why? Because some less-scrupulous manufacturers give WPC figures that don't cover the full bandwidth of human hearing (you should look for ratings based on 20-20,000 Hertz [Hz]), making them look more powerful than they are. Also, a speaker's "sensitivity" -- how loud it sounds given a set amount of power -- has a large impact. A speaker with higher sensitivity will sound comparatively louder, not necessarily "better".

The bottom line may surprise some people: A clean (meaning low total harmonic distortion) 10-40 WPC is typically plenty for normal listening in moderately-sized rooms. Many receivers and amplifiers have much more -- 80 WPC and higher -- so they can handle momentary peaks: like a loud cymbal crash or an explosion in a movie. One last thing: All things being equal, you must double the WPC to audibly hear a difference in perceived loudness.

Boxes, Subs and Satellites

What's complicated things beyond power requirements are the many, many different types of speakers now available. Your choice used to be "big, bigger, and biggest" -- wooden boxes that took up some, more, or a lot of space. That's all changed.

Now, you can buy tiny "sub/sat" systems, in-wall or in-ceiling models that virtually disappear, or the new-ish "on-wall" speakers designed to complement flat-panel displays. And you can still buy the big floor-standing models, which arguably still produce the best sound.

Why the mushrooming number of choices? The subwoofer.

How Low Can You Go?

A subwoofer is designed to do one main thing: play the lowest frequencies audible to humans -- typically 20-100 Hz. Because recreating these low frequencies requires the movement of a lot of air, speakers that can produce them by definition require a large enclosure. Thus a "do-it-all" speaker -- one that can reproduce the entire audible frequency range -- needs to be large. But if you have a single speaker (the subwoofer) solely focused on the lowest frequencies, all of the other speakers in a system can be much smaller.

Thus, "sub/sat" systems appeared (a subwoofer with typically five very small speakers called satellites), and have become very popular. And for good reason. A subwoofer -- now also becoming smaller, thanks to advanced electronics (usually around one foot square) -- is placed in the room. Placement is flexible, as the lowest frequencies are less directional, so placements behind a couch or under a table is possible. Then the front, center, and surround satellites, which are often only 5" or so tall, are placed appropriately. The result: good to very good sound, without the big speaker towers.

Keep it Hidden

Because of subwoofers, in-wall and in-ceiling speakers (which used to be a joke if you wanted quality sound), are now a real option. Also called "architectural" speakers, these used to be synonymous with thin, tinny sound -- mainly because a speaker that is mounted in a wall or ceiling by definition just can't be that large -- limiting their ability to create the lower frequencies. But augmented by a subwoofer, speaker manufacturers can focus on having their in-wall/in-ceiling speakers create quality sound in the middle and upper frequencies -- sounds that don't require moving a lot of air and thus big boxes. Properly configured, better-quality architectural speakers can provide the best of both worlds: full, rich sound, with no visible boxes in the room. They are an especially good choice if you're building a new home or performing a major remodel, as the wiring necessary can be installed before the walls are hung.

Subwoofers themselves can be hidden. There are models designed to be installed into walls themselves, although this requires some advanced planning, as the wall's framing must be suitable and the wiring must be planned carefully. Easier still is hiding the subwoofer in a cabinet or window seat. Vibrations must be controlled, however.

This Must Be The Place

Where do these speakers go? As we said, subwoofer location is flexible but the placement of the remaining speakers is important. For the best stereo imaging, the front left and right speakers should be placed such that the prime seating position is at the tip of an equilateral triangle, with the speakers at the other ends. The center speaker, which for movies and TV is the most important (it plays the dialog), should be placed directly above or below the display. The primary surround speakers should be located to the sides and slightly behind the primary seating area, approximately 7' off of the floor.

Now, are you ready to have your hair blown back?