"The depth of the sound field" is the "depth sense" we often say. The "depth sense" is different from the "sense of layering" and "positioning", because the level and positioning are not much related to the sound field, but the sense of depth still belongs to The scope of the sound field. Like the "width of the sound field", many people will say that the depth of his family's sound field has long been broken out of the wall, so that it is to the street. This is of course just an adjective of self -satisfaction. The real "sound field depth" refers to the distance between the front line instruments and the last line instrument in the sound field. In other words, it is likely to refer to the distance between the violin and the drum and the fixed sound drum. "Wide to neighbors and deepen the street" should be included in the "sense of space". This problem needs to be discussed in the future. Some equipment or environments are too low or low -frequency, so the positions of big drums and fixed sounds will be ahead. At this time, the depth of the sound field is of course poor. On the other hand, the position of some sound fields shrinks backwards, and it is mistaken for the depth of the sound field. In fact, it is wrong. I don't think you have seen a band that will be scheduled into a vertical strip. As long as you grasp the concept of "the distance between the violin to the fixed sound drum and the drum", you will be able to accurately tell the depth of the sound field.