1. In the case of the same number of turns and volume, the "inductive reactance" value of Hollow inductor is generally lower than that of solid inductor, Hollow inductor is more suitable for the occasion with wider frequency, and solid reactance has serious frequency tendency; also That is to say, the hollow inductive reactance allows most audio or audio frequencies to pass, while the solid inductive reactance is selective and only allows a part to pass.

2. The reason for using these two kinds of inductances is mainly because of the needs of audio and audio frequency. In the frequency divider, hollow inductances are generally used in the front stage, theoretically allowing 20~20KHz audio to pass through. After the frequency division, only the audio signals after the frequency division are allowed to pass through 20~1KHz, 1K~10KHz, 10~20Hz, etc., so as to achieve the purpose of frequency division output. In fact, solid or Hollow inductors are There will be a lot of attention.