A speaker is a device that converts electrical signals into sound waves. The electrical signal is applied to the speaker’s voice coil, which vibrates back and forth. This vibration causes the speaker’s cone to move, which in turn creates sound waves.
The amount of power that a speaker needs to produce sound depends on its size and design. Larger speakers need more power than smaller speakers. Speakers with more bass also need more power than speakers with less bass.
An amplifier is a device that takes a low-level audio signal and increases its power so that it can drive a speaker. The amplifier does this by using transistors to amplify the signal. Transistors are semiconductor devices that can amplify electrical signals.
The amount of amplification that an amplifier provides is measured in decibels (dB). A typical amplifier will provide between 20 and 100 dB of amplification. The amount of amplification that a speaker needs will depend on the speaker’s sensitivity. Sensitivity is a measure of how loud a speaker can get with a given amount of power.
Passive Speakers
Passive speakers do not have an amplifier built-in. They need to be connected to an external amplifier in order to produce sound. Passive speakers are typically less expensive than active speakers, but they offer some advantages.
One advantage of passive speakers is that they are more modular. You can choose the amplifier that best suits your needs and budget. Passive speakers also tend to be more durable than active speakers.
Active Speakers
Active speakers have an amplifier built-in. This means that they can be connected directly to an audio source, such as a CD player or a smartphone. Active speakers are typically more expensive than passive speakers, but they offer some advantages.
One advantage of active speakers is that they are more versatile. They can be used with a wider variety of audio sources. Active speakers also tend to be more efficient than passive speakers, which means that they can produce more sound with less power.
Why Do Passive Speakers Need an Amplifier?
Passive speakers need an amplifier because they do not have the power to produce sound on their own. The amplifier takes the low-level audio signal from the source and increases its power so that it can drive the speaker.
The amount of power that an amplifier needs to provide for a passive speaker depends on the size and design of the speaker, as well as the type of music that will be played. For example, a pair of bookshelf speakers that will be used to play classical music will need less power than a pair of floorstanding speakers that will be used to play rock music.
How to Choose the Right Amplifier for Passive Speakers
When choosing an amplifier for passive speakers, there are a few things to keep in mind:
- The power output of the amplifier should be at least equal to the power handling capacity of the speakers. This will ensure that the amplifier does not damage the speakers.
- The impedance of the speakers should match the impedance of the amplifier. This will ensure that the amplifier is able to deliver the correct amount of power to the speakers.
- The amplifier should have the features that you need. For example, if you want to be able to connect multiple speakers to the amplifier, you will need an amplifier with multiple channels.
Conclusion
Passive speakers need an amplifier to produce sound. The amount of power that the amplifier needs to provide depends on the size and design of the speakers, as well as the type of music that will be played. When choosing an amplifier for passive speakers, it is important to consider the power output, impedance, and features of the amplifier.
