In the audio industry, many audio companies are actively displaying their own line array speaker systems or their own agents. When evaluating these line array systems, do you know what standards should be adopted? Let's take a look at the "correct listening posture of the line array".
One, hit far
The ability of the speaker system to "reach far" is the ability to deliver the original sound signal to the last row of audience areas without distortion and accuracy.
Generally speaking, the place of use of the line array is outdoors, even if it is not outdoors, at least it has to face a relatively large listening environment. It is also the main reason why many projects choose line arrays.
Stand at the place furthest away from the speaker and experience whether the sound still feels "in front of you".
The "distance" is completely audible. When you walk away from the speakers, if you feel that the sound clarity is lost, such a system can't reach the distance. Note that "speech intelligibility" is another very important concept. It is different and not equivalent to "sound pressure level".
The thing to pay attention to here is the high pitch, if the high pitch is not too far, it will fail. Everyone knows that the wavelength of high frequency and ultra high frequency is very short, and the air absorbs high frequency very quickly, which causes outdoor sound reinforcement. This is a natural phenomenon. Therefore, large-scale sound reinforcement and long-distance sound reinforcement need to solve the high frequency distance. Transmission problems. This is very important for the selection of high-frequency horns and the overall coupling between the cabinet modules. If the far-field can only be used for midfield and near-field audiences, it cannot serve far-field audiences to hear the same sound quality. Basically, only mid-range, mid-low and ultra-low frequencies are left for back-field audiences, so the front and back frequency characteristics cannot be evenly covered. , This is definitely a failure!
2. Straight frequency response
Is the frequency response curve of the audio system or speaker products required to be straight? Many people argue on this issue, and the focus of the argument is often that what sounds good is not necessarily straight, and what is straight is not necessarily good. The actual situation is the same, but the sound quality is very subjective, you think it sounds good, others may not think it. However, in the test sound field of the line array, the flat frequency response is certain. As mentioned earlier, the line array usually faces a relatively open listening environment. No matter where the audience is, the sound they hear should be the same. Big.
Therefore, the line array requires sound transmission to have a flat frequency response and coverage regardless of the near, middle, and far fields of the venue. Always changing the frequency response of the mid/high frequencies indicates poor coupling in the vertical plane.
You can listen to the sound performance while walking from the near field to the far field.
3. Horizontal coverage
The high frequency dissipates quickly, and the high frequency is viewed from the far distance, and the horizontal coverage also depends on the high frequency. In fact, the horizontal coverage angle of the high frequency can be said to be the horizontal coverage angle of the system. The higher the frequency, the sharper the direction and the more difficult it is to handle into a wider angle.
While walking from left to right in front of the array, listen to whether the sound feels "in front" everywhere, and feel the "speech clarity" of the system at the maximum expansion angle. After the maximum angle, the sound is There is a feeling of "roll-off", like a "roll-off" similar to the frequency response curve. The actual sense of hearing of most arrays is not correct with the parameters on paper. Generally, they are more "beautiful" on paper, but in reality it is far from the case.
The combination of conventional speakers will definitely talk about acoustic interference. Although the linear array reduces the interference when the speakers are stacked, it is unavoidable to face this problem, because the linear array has always been combined with many units, so the acoustic interference If the problem is not solved well, it will produce a strong tree-like filtering effect and other sound quality deterioration. The appearance of this kind of sound coloring cannot be adjusted and corrected with the equalizer and the phase. Therefore, there is serious acoustic interference in the middle and high frequencies, and the linear array must fail.
5. MF/HF direct sound
There will never be MF/HF direct sound below the array. If any MF/HF sound appears in the lower area of the array, then this is very undesirable. These poorly coupled "edge" sounds are heard in the lower area. The same amount of energy is bounced down and also bounced up to the ceiling.
Stand under the array to listen to the sound. The mid-frequency/high-frequency sound conveyed to the audience should only be the sound reflected from the room.
Other attention issues:
Inadequate control of the horizontal and vertical angles is also a failure. The linear arrays are hung vertically, so the high frequency part of the vertical angle is controlled by the high frequency horn and the overall precise seamless coupling, while the intermediate frequency and low frequency (coupling is a very complicated matter, the frequency is different. The coupling characteristics It is not the same) by direct coupling between the speaker units. The more modules, the smaller the vertical angle, but the horizontal angle coverage is another science, it depends on the key to your cabinet design.
Of course we hope that the larger the horizontal angle of the line array, the better, but this is impossible, but it must be accurately and uniformly covered in a relatively wide range. Generally, a good line array can be between 90-110 degrees. The level of coverage. The coverage of the horizontal and vertical angles is even, so that the audience can fairly enjoy the same frequency characteristics. If this is not possible, it will violate the original intention of the larger listening environment of the linear array.