Professional speakers are the mouthpiece of the entire sound system, and the correct selection of speakers is essential. When buying speakers, there are two points that must be understood: First, the purchase of speakers must be a compromise between price and performance, or a consideration between quality level and cost. The price of a single professional speaker can range from a few hundred yuan to tens of thousands of yuan, and there are also imported high-end speakers that sell for hundreds of thousands of yuan. Of course, the performance of these high-end speakers is much better than ordinary mass-produced products. Simple comparison; the second is thinking about methods and uses, that is, choose different speakers for different purposes.
1. Choose a good performance index
First, check the relevant technical parameters in the speaker clarification book, such as effective frequency range, impedance, flexibility, rated power, directivity, distortion, etc. When consulting the clarification book, it should be noted that the effective frequency response range has strict rules in the international IEC standard, but some manufacturers only mark the frequency response range, and do not provide the change of the frequency response curve or clarify the frequency response range. It is measured according to which standard, so the frequency response parameters provided in this way are meaningless. For example, there is a pair of speakers marked with a frequency response range of 30Hz~20kHz, but in practice, the low frequency is significantly attenuated below 70Hz, and may have been attenuated by 20dB at 30Hz, and the high frequency can only be smoothly extended to 14kHz. On the contrary, the frequency range of the other pair of speakers is marked as 40Hz~16kHz±3dB. Although it seems that the frequency response range of the latter pair of speakers is not as wide as the previous pair, in fact the latter pair of speakers is better than the previous pair, due to its frequency. The response curve indicates that it only changes within ±3dB, so it is much flatter. In addition, attention should be paid to the rated power index. Countries and even factories often have very different power calibrations, and some indicate the short-term maximum noise power. , Peak receiving power, music power, instantaneous receiving power, so the value is often many times larger than the rated power. And the measurement methods and regulations of various countries are often lenient and strict. For example, the Japanese JIS norms are often wider than the international IEC norms. Therefore, it is necessary to know what standard test is used when purchasing, indicating the rated power or the peak received power, and the power of the speaker.
The rate should consider the size of the listening hall and a certain amount of power storage. Under the same conditions of other elements, high-power speakers are usually selected. Because such products have power margins, they are not easy to cause distortion during high-power playback. The speaker impedance should be matched with the amplifier. It is not good to be too large or too small, especially not too small to prevent damage to the equipment. The flexibility of the speaker should not be too large or too small; the sound pressure level of about 100dB/W/m or higher is more suitable. The frequency response of the speaker should mainly be the lower limit, because the high frequency can reach the standard, but the bass can reach the standard. It is more difficult, so you should choose below 40Hz as the lower limit specification.
2. The relationship between speaker flexibility and power
There are three important factors in determining the output sound pressure level of a speaker: the efficiency of the speaker, the receiving power of the speaker and the output power of the amplifier. Everyone knows that the higher the efficiency of the speaker, the less effort it will be to push the amplifier. The most popular PA speakers in outdoor concerts are high-efficiency speakers, and their volume is surprisingly loud. In a space of 800m3, the sound pressure level of the speakers must be at least 110dB. If the flexibility of the speaker is 95dB/W/lm, the amplifier must also have an output power of 2000W to enable the speaker to deliver such a large sound pressure level. In contrast, if the speaker is replaced with a flexibility of 105dB/Wilm, the amplifier only needs 200W of power. Compared with the former, the minimum output power request of the amplifier and the receiving power of the speaker only require one very much of the former.
3. Definitely good investment ratio
Due to the important position of the speaker in the sound system, the investment ratio to it should also be the largest. If I combine the sound, the investment of the speaker accounts for 30%~50% of the investment of the sound system, so as to ensure the sound quality.
4. Definitely like the sound according to its use
There are many types of speakers, and the tone characteristics of speakers in different countries are not the same.
5. Carefully check the appearance
The appearance of the speaker should be serious and generous, not too fancy. After selecting the model, carefully check the appearance to see if there are scratches or cracks, and also check whether the wiring sockets are strong and whether the protective net cover is loose or not.
6. Listen carefully
You should listen carefully to the speakers you choose. It is best to use the amplifier that you plan to match with it to advance the audition to obtain first-hand material. During the audition, you should play the music records you are familiar with. There can be more types, such as orchestral music, vocal music, electronic music, etc., to see which type of music is better for playback.