How Speakers Work

A little about how speakers work  
Sound is simply vibrating air. So it makes sense that for a speaker to produce sound, it must make the air around it vibrate. That in a nutshell is what a speaker does. But how it makes air vibrate is a bit more involved. Since a little inside knowledge about sound and speaker design can be helpful when selecting speakers for your home entertainment system, let’s take a closer look. I promise it won’t be too complicated.

Show and tell 
A speaker makes sound by vibrating the air around it. Here’s a fun experiment. Take a metal ruler and hold it securely on the edge of a table with about 9-10 inches of the ruler hanging free. Now, pluck the free edge of ruler with a finger like you would pluck a guitar string. The ruler will vibrate up and down. Place your ear near the vibrating ruler; you should hear a distinct tone. Next, shorten how much of the ruler hangs over the edge of the table. Pluck it again. Notice how the tone is higher pitched. If you experiment with different lengths, you’ll notice how the pitch changes each time.

We can learn three things that apply to speakers from this little demonstration. First, a vibrating object creates sound. Second, a large vibrating object creates a low-pitched sound. Third, a small vibrating object creates a higher pitched sound.

Woofers, tweeters, and other animal sounds
In a speaker system, the objects that vibrate are called the drivers. From our experiment, we learned that it takes a large object to produce low-pitched tones and a small object to produce high-pitched tones.

If a speaker system has only one driver and it’s large, it will only accurately reproduce the low tones. The high tones will be lacking. Similarly, if a speaker system has only one small driver, the high tones will be crisp and clear, but the low will be lacking. The solution is to have both large and small drivers, each a specializing in a particular range of sounds.

The big driver is called the woofer (a large dog’s woof can be very low pitched). The little driver is called a tweeter (you can probably figure that one out). Some speaker systems can have even more drivers; each one specialized for a particular range of sounds. But the woofer and tweeter are probably the most important.

As we have learned, the size of the woofer helps determine how well the speaker produces the deeper low tones, or as we call it, the bass. That’s why larger speakers usually sound fuller and richer than smaller ones.

The crossover
There’s one more important part of a speaker that needs mentioning. It’s called the crossover. Think of it as a traffic cop. Like a cop directing traffic left, right or straight ahead, the crossover directs the high sounds to the tweeter and the low sounds to the woofer. It’s a very important part of the speaker and greatly influences the system’s overall sound performance.

Talk to the experts
Now that you know a little bit more about speakers, it’s time to listen to a few. You will notice how some tend more towards the low tones, and some more towards the high tones. And what about the sounds in the middle? Do they sound natural and clear? Let your Sound Advice systems designer be your guide. Choosing speakers can be fun and enjoyable if you know what to look for. So call us or click for a Free In-Home Consultation so we can help you find the perfect speakers for the room, your taste, and of course, your budget.