A.降低整體增益; B.降低低頻增益; C.降低高頻增益; D.增加高頻增益; E.增加低頻增益。
A.3:1; B.1:3; C.1:1.5; D.1.5:1; E.2:1。
A.10~15mm; B.15~25mm; C.25~35mm; D.0.15~0.25cm; E.0.25~0.35cm。