Choosing a sound system for your event or venue can be a difficult task if you don’t speak the lingo.
Descriptions and specifications of audio products can sometimes be difficult for novice buyers to understand, even with the Web at their disposal.
Fortunately, AudioLinks has compiled a glossary of audio terminology featuring handy definitions of essential audio terms to help you decide exactly which sound system fits your needs.
From our glossary, here’s a sample selection of 8 audio terms you need to know when choosing a sound system:
Apart from decibels (see number 4 in this list), the watt is the most commonly used term to describe the power of a system. Specifically, it refers to the power that an amplifier delivers to a speaker. As a measure of the volume of a system, it’s meaningless without knowing more about the speakers, but in general it’s safe to assume that the more watts a system offers, the louder it sounds.
Headroom is the amount of power (in watts) that an amplifier holds “in reserve” to deal with brief spikes in signal. Headroom is why you always want to overestimate the wattage you need, in case the system encounters a sudden surge (for instance, from someone plugging in a microphone without turning down the volume).
For maximum headroom, and safety, choose a PA system with double the amount of power you think you’ll need for your event.
Clipping is the popping, distorted sound that means an amplifier is exceeding its power output. When clipping occurs, especially for an extended period of time, odds are you’re damaging your amplifier, speakers, or both!
Again, choosing an amp with adequate headroom (and speakers rated for the proper wattage) will help alleviate this problem.
Named after Alexander Graham Bell, a decibel (dB) measures the relative loudness of a sound as it arrives at the eardrum. As stated in our glossary, “a difference of approximately 1 dB is the minimum perceptible change in volume, 3 dB is a moderate change in volume, and about 10 dB is an apparent doubling of volume.”
In general, a whispered conversation registers around 15 to 25 dBs. Add 10 dBs 10 times, doubling the volume each time, and you get to 120 dBs, which is the approximate volume of a loud rock concert! It’s easy to see why, at this stage, you need to take steps to protect your hearing.
5. Dynamic Range
Technically, the dynamic range of audio content is the difference in decibels between the loudest and softest moments. In audio, it refers to how big of a change the amplifier (or other component) is able to reproduce before it distorts.
Dynamic range shouldn’t be confused with frequency range, which measures a speaker’s ability to reproduce both low and high sounds. However, for both metrics, the wider the range the better the system sounds.
Gain is the ratio of the input signal to the output signal. In short, it’s a fancy word for volume: increase the gain, and the sound gets louder.
On PA systems, the gain control functions the same as a volume knob for an input source such as a microphone. Turn up the gain on your mic, and you will turn up the mic’s volume. Though, if you increase the volume too much, you’ll get feedback.
Feedback is the screechy sound that occurs when a microphone gets too loud or gets too close to the output speaker. The output gets “fed back” into the microphone, is amplified through the speaker, gets picked up again, and the process continues until the all-too-familiar feedback squeal kicks in.
Or, to quote AudioLinks’ glossary: “A signal is received by a microphone, amplified and passed out of a loudspeaker. If the microphone can then receive the sound from the loudspeaker, a looping effect will be created. If too much sound looping occurs, the signal will ‘run away’ and quickly degrade into an oscillation at some frequency. The resulting sound is a ‘squeal’, ‘howl’ or a combination of both.”
Impedance is a measure of electrical resistance specified in Ohms.
When choosing speakers, it’s important to match the impedance of the speaker to the rating of the amplifier for maximum performance. In the case of some impedance mismatches, you can damage your gear, so it’s critical to pay attention to this specification.
Fortunately, manufacturers such as Fender, Samson and Yamaha offer prepackaged PA systems to minimize confusion and maximize convenience. Selecting a fully-compatible system from one of these manufacturers is a safe (and easy) option.
The AudioLinks Glossary Is Here To Help
Whether you’re choosing a delegate microphone unit, a tour guide system, or a PA system, the AudioLinks glossary will help you navigate through the jargon to find the system that fits your needs!
Have a suggestion for something you’d like to see covered in our glossary? Leave it in the comments below!