Intrinsic Advantages of Mono Cartridges: Low THD%

Two MC cartridges of the same model, one a mono and the other a stereo version, are measured here using the same 1000 Hz sine-wave test track. The mono version (1st chart below) shows a much lower THD% .

One can argue that, since the test track is in mono with only lateral modulation, any vertical movement of the stylus, which could be from imperfect record cutting, etc., is counted as distortion. A mono cartridge will pass on most if not all of the vertical movement, hence the measured distortion will be smaller than a stereo cartridge.

Mono 唱頭的好處之一，是THD% 測起來會比立體頭低很多。因為失真率是以 mono 的 1000Hz 訊號測出的，這代表立體頭在播放 mono 音軌時會付出較高失真的代價。所以，用 mono頭聽 mono 唱片，應該是有失真較低的優勢。

所有mono 唱片，不管是以前用老mono刻片頭或是近代立體刻片頭刻出來的，溝槽難免會有一些垂直向的立體運動成分。但既然原始訊號裡沒有立體資訊，這些都算是刻片的失真。用 mono 唱頭播放，感應不出這些不該有的失真，理論上會比較接近原來母帶，也是一種好處。

以下兩個圖，是同一型唱頭的 mono 與立體版本，裝在同一唱臂/唱盤。測量出的失真率。可以看到相當明顯的差異。