impedance matching 

Impedance matching is one of the key factors in selecting speakers. When the impedance of the speaker is equal to the output impedance of the amplifier, the two can work together to achieve optimal efficiency. If the impedance does not match, it may cause power loss and even distortion. For example, when the impedance of the speaker is less than the rated load impedance of the amplifier, it is easy to overload the amplifier, resulting in transient distortion of the signal; When the impedance of the speaker is greater than the rated load impedance of the amplifier, the amplifier may not be able to easily push the speaker to produce sound during high signal. Therefore, when selecting a speaker, it is important to ensure that its impedance matches the output impedance of the amplifier it is paired with.

Power adaptation

Power adaptation is equally important. When choosing a speaker, the corresponding power of the speaker should be selected based on the rated power of the amplifier. If the power of a speaker cannot meet the power requirements of the amplifier, the requirements can be met by connecting several speakers in series or parallel, so that the total power of the speakers is compatible with the power of the amplifier. For example, the impedance of speakers used in home audio equipment is usually 4-8 Ω, while the impedance of speakers in professional equipment is 12-16 Ω. If the output power of the power amplifier is 100 watts and the power of a single speaker is 50 watts, the power requirement can be met by parallel connection of two speakers.

Frequency characteristic selection

In order to achieve good sound quality, speakers with different frequency bands need to be used in combination. In the low frequency range, cone speakers are mainly used, which have stable performance and low price. Larger aperture speakers can be used to obtain rich bass, while smaller aperture rubber edge speakers can be selected to improve low-frequency characteristics. In the mid to high frequency range, ball top and flat panel speakers are mainly used, which have good frequency response, transient characteristics, and nonlinear distortion. In a three-way speaker, the same type of speaker should be used for both the high and mid tones to ensure a balanced tone quality.

Appearance identification and listening test

When purchasing a speaker, the first step is to conduct visual identification. Check the trademark of the speaker to confirm if the nominal impedance and rated power match the amplifier. At the same time, observe whether the speaker leads are intact, whether the paper basin is damaged, and whether the folding ring and basin frame adhesive are firm. When checking the speaker, gently press down on the paper tray with both hands, listen carefully for any friction sound, and be careful not to apply too much force when pressing the paper tray to avoid damaging it.

Trial listening is also an important step in selecting speakers. Connect the speaker to an amplifier circuit that meets the required impedance and power, and listen for any hoarse, harsh, or other unwanted sounds when the speaker produces sound. A high-quality speaker should produce sound that is layered, full, harmonious, clear, pleasant, and comfortable. It is best to choose music that you are familiar with during the listening test in order to better assess the sound quality of the speaker. For example, choosing a piece of music that contains rich low-frequency, mid frequency, and high-frequency elements, such as a symphony, can comprehensively test the performance of speakers in different frequency bands.