Maybe a lot of musicians have such a habit, like watching some studio show videos, on the one hand, others can feast their eyes on various equipment, on the other hand, they can learn some knowledge more or less. Well, if you have such a habit, you may have noticed that everyone's placement of speakers is roughly divided into two types: horizontal placement and vertical placement. So the question is, how should the monitor speakers be put? What kind of benefits and problems will the two methods bring?
1. Frequency division design
To answer this question, we must first briefly understand the design of the monitor speakers. The monitor speakers we see daily are mainly divided into two-way and three-way speakers. Generally speaking, there is a difference between two units or three units in a speaker (note that this statement is not rigorous).
Then why adopt such a design? Can't one unit work?
There are only one-unit speakers, but these speakers are usually smart speakers with a price-performance ratio, and the sound quality is often not what they are after.
The main sound quality "smart" speaker, Apple's HomePod, it also has many built-in speaker units of different specifications. The reason is that when you only have one unit, the frequency band that the speaker can reproduce is limited. This is unacceptable for monitor speakers. Although you cannot reproduce the low frequency of 20Hz, your high frequency At least 20kHz.
For this reason, the frequency division design came into being-the frequency range of the human ear is divided into multiple pieces, and different speaker units are used for playback. The two-way speaker divides the frequency range into two parts, and the three-way frequency divides into three parts, and the rest is the same. But this kind of crossover design will bring new problems. To a certain extent, this is the reason why two-way speakers are generally placed vertically-the problem of phase cancellation at the crossover point.
2. Phase cancellation
The frequency division design mentioned above is realized by the filter circuit. Although the slope of the ideal filter is infinite, that is, it is cut straight across, but there is no such filter in real life.
Take a simple two-way speaker as an example. You will find its crossover point in the user manual. We assume it is 1.8kHz. Ideally, the low-frequency unit of this speaker should reproduce a signal from 20Hz to 1.8kHz. The high-frequency unit will reproduce the signal from 1.8kHz to 20kHz, and the two complement each other but do not overlap each other.
But in fact, the signal reproduced by the low frequency unit contains a signal slightly higher than 1.8kHz, and the signal reproduced by the high frequency unit also contains a signal slightly lower than 1.8kHz. There is an intersection between the two. This part will cause the problem of phase cancellation.
The two-way speaker is designed to be placed vertically because it can ensure that when the listener is off-center, the distance between the high-frequency unit and the low-frequency unit reaching the listener’s ears is almost zero. This is broken when the crossover speaker is placed sideways.
At this time, if you move left and right, the distance difference between the tweeter and the woofer to your ears will no longer be 0. The original two sounds with a phase difference of 0 may become 180 degrees at a certain point, that is, cancel each other. As a result, the sound has a huge change.
Logically speaking, this problem also occurs on three-way speakers, but why can three-way speakers usually be placed sideways? This is because the crossover point of a three-way speaker is different from that of a two-way speaker. I know that everyone does not like mathematics, so we only talk qualitatively and not quantitatively.
The double-frequency speaker assumed above has a crossover point of 1.8kHz, and the sound wavelength in this range hovers around 18.9cm, that is to say, when the distance between the two speakers and our ears is 9.45cm (18.9/2) , It will produce a phase difference of 180 degrees, the 1.8kHz signal will be cancelled out, our ears can't hear it at all.
To achieve the above-mentioned distance difference, how far do we need to deviate from the center horizontally?
For a normal monitoring distance, we only need to deviate from the center by about 15 to 25cm, which means that if you twist your head and reach for the nearby instrument or effector, the sound you hear will change dramatically.
However, the crossover point of the bass unit and midrange unit of the three-way speaker is generally around 400Hz. At this time, the wavelength is close to one meter, which is nearly 5 times longer than the 18.9 cm at 1.8kHz. At this time, you are slightly around. Move, even if the movement is a little louder, the sound will not change much. This is why three-way speakers are usually ok and recommended to be placed sideways.
So, should the monitor speakers be placed vertically or horizontally?
The standard answer to this question is to check the user manual of the model you are using, and place it according to the manufacturer's suggested placement method, which is the most trouble-free way.