Effects of flat surface near the 1st reflection point

（中文在後）
The effects of a flat surface, here a door, near the 1st reflection point of a speaker are quite visible in the first impulse-response chart. Asking a person to walk over and stand in front of the door makes immediate, visible differences as in the 2nd chart.

喇叭的側方第一反射點附近的平滑面的影響，可以在第一個 impulse response 圖明顯看到。請一位朋友站在門前，就立刻造成第二圖裡明顯可見的差異。