Excellent earphone sound should have the following characteristics

The second feature is the low frequency of the headset.

The lower low frequency (40Hz-20Hz) and ultra-low frequency (below 20Hz) are perceived by the body, and the human ear is not sensitive to these frequencies. The earphone can reproduce the low frequency perfectly, but because the body cannot feel the low frequency, 

1. The sound is pure, without any unpleasant "hiss", "buzz" or "boo".

2. The balance is good, the timbre is never too bright or too dark, the energy distribution of high, medium and low frequencies is uniform, and the fusion between frequency bands is natural and smooth, without abrupt and burr.

3.  High frequency extension is good, delicate and smooth.

4. Low frequency diving is deep, clean and full, elastic and powerful, without any feeling of fat or slow.

5. The medium frequency distortion is very small, transparent and warm, and the voice is kind and natural, thick, magnetic, and not exaggerating the dental and nasal sounds.

6. Good analytical power, rich details, and small signals can be clearly replayed.

7. Good sound field description ability, open sound field, accurate and stable instrument positioning, sufficient information in sound field, no empty feeling.

8. Dynamic has no obvious compression, good speed sense, no distortion or little distortion at high volume.

Such a headset can perfectly replay any type of music, with good fidelity and sense of music. Long term use will not cause fatigue, and the listener can be immersed in music.

A headset with a completely flat low frequency often makes people feel that the low frequency is insufficient and the voice is thin. Properly raising the low frequency is also a common method used by the headset, which can make the sound of the headset appear full and the low frequency is deep. Light earphones and earplugs are the most commonly used means. They have small diaphragm area and cannot reproduce deep low frequencies.