In Uganda, and not only here, many people choose speakers by their watts. Some time back a pastor came to my office looking for 25,000 watt speakers. He had 2,000 watt speakers and wanted louder sound, so I assume he expected speakers that were more than ten times louder.
In the local market, shops sell speakers by watts, yet the key word is the one above: louder. Not watts, and not size.
So what should you look for when you buy speakers?
- How loud it can be.
- How good its sound is.
Here are the answers.
1. Loudness is measured in decibels (dB), as SPL (sound pressure level). Most manufacturers test and publish a speaker’s sensitivity like this: xx dB at 1 W / 1 m. What does that mean? It means that when the speaker gets 1 watt of power and you measure it 1 metre away, this is how loud it is: xx dB.
To compare apples with apples, check each speaker’s sensitivity measured the same way, at 1 W / 1 m. Some manufacturers confuse buyers by publishing only the maximum SPL and a few other figures, so I recommend you always look for the 1 W / 1 m figure.
For example, one speaker can give 96 dB at 1 W / 1 m, while another with the same or even higher wattage gives only 81 dB at 1 W / 1 m.
Think of energy saving bulbs. A 5 watt bulb can give more light than an old 60 watt bulb. Do you care about the power (watts) or the light? By the way, the brightness of a bulb is measured in lumens, not watts. I will explain that another time.
You should look for the louder speaker, just as you look for the brighter bulb, not the one that consumes more power. And don’t forget: the higher the consumption, the higher your electricity bill, or the bigger the generator you will need.
2. How good the sound is. We learn this from the speaker’s frequency response. What is that? In simple terms, it is the treble and the bass, the range of sound the speaker can reproduce.
Without going too deep into the technical side, you need to know that the wider the frequency range, the better the speaker.
The full range of human hearing is from 20 Hz at the low end to 20,000 Hz at the high end. You can find speakers that cover the full range or only part of it. The lower it goes at the bottom and the higher it goes at the top, the better.
For subwoofers you only need the low frequencies, so the lower the sub goes, the deeper its sound. Then again, it depends on your application and preference. For example, the bass you want for jazz and the bass you need for hip hop are not the same.
These are only the basics of how to select and compare speakers. There are more things to look at, such as impedance, intelligibility and a few more, and I will be writing about those soon.
