Professional audio basic knowledge classic

　　1. What is the withstand power of professional audio speakers?

　　As the name suggests, the withstand power of professional audio speakers means "the input speaker will not be damaged if it does not exceed the marked power, and it will be able to withstand it."

　　There are several ways to express the withstand power of professional audio speakers, which can easily cause misunderstandings by users and cause damage to the speakers due to improper use. Some of the parameters of professional audio speakers are marked with rated power, that is, long-term power, which means that they will not be damaged under this power state for long-term use. The factory tested the rated power at a constant temperature of 20°C, using pink noise signals for 48 hours of continuous work. The use environment in the KTV private room is relatively harsh, and the music contains many large dynamic peak signals. It is recommended that the input power is lower than the rated power by more than 20% to use the speaker, which will be much safer. Some speaker parameters are marked with peak power, which is 3-4 times the rated power. For example, the power label of GAEpro brand KS-10 is 450W with peak power. The speaker's ability to withstand peak power is conditionally limited. The time setting is 1 second, and it can only be repeated 10 times. If it exceeds it, it may be damaged. The speakers with peak power should be used with special care. It is recommended that the power does not exceed the peak power. 1/4 of power.

　　2. What is the rated output power of the power amplifier?

　　The rated output power of the power amplifier refers to: "the long-term output power under the condition of no distortion (generally the output distortion does not exceed 1%)". In this state, the power amplifier is safe and reliable. In fact, there are several prerequisites: one is that the mains voltage is required to be the standard 220V. If the mains fluctuates, the output power of the power amplifier will also change; the other is that there are impedance requirements for the load (speaker), such as 2 *150W (8Ω) power amplifier, under 4Ω load, the output power may reach about 230W. The ambient temperature of the third factory during the output power test of the power amplifier is 20℃. If the heat dissipation is not good when used in the KTV audio room, even if it is working under the rated power condition, the power amplifier may be damaged. The rated power of the four power amplifier Power refers to the undistorted output power. It does not mean that the power amplifier can only output this power. If the power distortion is allowed to increase the output (increase the volume knob), the output distortion power is very large, far exceeding the rated power. For example, the maximum output voltage of a 150W (8Ω) power amplifier without distortion should be less than 35V (power=voltage2/resistance). When distorted, the output voltage may rise to 40V, and the distortion power at this time will reach 402/8 =200W.

　　3. How to match the power when choosing professional power amplifiers and professional audio speakers?

　　When choosing professional power amplifiers and speakers, we recommend that the rated power of the professional power amplifier should be slightly larger than the rated power of the speaker, generally 20-30% is appropriate, and at least it should be equal. The rated power of the professional power amplifier must not be less than the rated power of the speaker. Small horse-drawn cart". A small horse-drawn cart will cause the entire system to perform softly and weakly, and the dynamic and music performance levels will deteriorate. If the user increases the bass tone knob or the volume knob too much in this case, the output will be distorted. Pedestrians often say "clipping", resulting in direct current output (under normal circumstances, the output waveform of the power amplifier is an alternating current sine wave, and after distortion, it will "clipping" to form an approximate direct current). In the case of DC output, the power amplifier can no longer control the speaker, so it will burn. When the power of the power amplifier is greater than the power of the speaker, it is necessary to control the output of the power amplifier not to be too large, so as to ensure that the power amplifier has enough "power reserve", has good dynamic performance, and will not damage the speaker.

　　4. Why do you often "burn the tweeter"?

　　The tweeter is the weakest link in the speaker. When the speaker is damaged, the tweeter is often the first to be damaged. Of course, improper use will also burn the woofer.

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