Bilingual edition: English is preserved and Chinese follows each unit. Terminology uses the confirmed v20260916 glossary; automated semantic review remains traceable.
中英双语版：英文原文完整保留，中文紧随对应单元；术语采用 v20260916 确认表，自动语义审校结果可追溯。

Tape Recording Process

磁带录音过程
This is an active graphic. Click any part for further details.
这是一个动态图形。点击任何部分以获取更多细节。
 Index

Sound reproduction concepts

Tape recording concepts

Reference
Rossing
Science of Sound
Ch 21
索引 声学再现概念 磁带录音概念 参考 Rossing 声学科学 第21章
 
HyperPhysics***** Sound
HyperPhysics ***** 声音
R Nave
 Go Back
返回








Erase Head

擦除磁头

Before passing over the record head, a tape in a recorder passes over the erase head which applies a high amplitude, high frequency AC magnetic field to the tape to erase any previously recorded signal and to thoroughly randomize the magnetization of the magnetic emulsion. Typically, the tape passes over the erase head immediately before passing over the record head.

在经过记录头之前，磁带会先经过擦除头。擦除头施加一个高幅值、高频的交流磁场到磁带上，以擦除之前记录的信号，并彻底随机化磁性乳胶的磁化。通常，磁带在经过擦除头之后立即经过记录头。

The gap in the erase head is wider than those in the record head; the tape stays in the field of the head longer to thoroughly erase any previously recorded signal.

擦除头的间隙比记录头的要宽；磁带在头的磁场中停留更长时间，以彻底擦除之前记录的信号。
Tape recording process
磁带录音过程
 Index

Sound reproduction concepts

Tape recording concepts

Reference
Rossing
Science of Sound
Ch 21
索引 声学再现概念 磁带录音概念 参考 Rossing 声学科学 第21章
 
HyperPhysics***** Sound
HyperPhysics ***** 声音
R Nave
 Go Back
返回
















Biasing

偏置

High fidelity tape recording requires a high frequency biasing signal to be applied to the tape head along with the signal to "stir" the magnetization of the tape and make sure each part of the signal has the same magnetic starting conditions for recording. This is because magnetic tapes are very sensitive to their previous magnetic history, a property called hysteresis.

高保真磁带录音需要将高频偏置信号施加到磁带头上，同时与信号一起作用以“搅拌”磁带的磁化，确保信号的每个部分在记录时都有相同的磁化初始条件。这是因为磁带对先前的磁化历史非常敏感，这一特性称为磁滞。

A magnetic "image" of a sound signal can be stored on tape in the form of magnetized iron oxide or chromium dioxide granules in a magnetic emulsion. The tiny granules are fixed on a polyester film base, but the direction and extent of their magnetization can be changed to record an input signal from a tape head.

磁化声信号可以以磁化铁氧化物或铬氧化物微粒的形式存储在磁带中。这些微粒固定在聚酯薄膜基底上，但其磁化方向和程度可以被改变以记录来自磁头的输入信号。
Tape recording process
磁带录音过程
 Index

Sound reproduction concepts

Tape recording concepts

Reference
Rossing
Science of Sound
Ch 21
索引 声学再现概念 磁带录音概念 参考 Rossing 声学科学 第21章
 
HyperPhysics***** Sound
HyperPhysics ***** 声音
R Nave
 Go Back
返回








Tape Playback

磁带播放

When a magnetized tape passes under the playback head of a tape recorder, the ferromagnetic material in the tape head is magnetized and that magnetic field penetrates a coil of wire which is wrapped around it. Any change in magnetic field induces a voltage in the coil according to Faraday's law. This induced voltage forms an electrical image of the signal which is recorded on the tape.

当磁化了的磁带经过录音机的播放头时，磁带头中的铁磁材料会被磁化，该磁场穿透围绕其缠绕的线圈。根据法拉第定律，磁场的任何变化都会在线圈中感应出电压。这个感应电压形成一个电图像，该图像记录在磁带上。

Problem: The magnetization of the magnetic emulsion is proportional to the recorded signal while the induced voltage in the coil is proportional to the rate at which the magnetization in the coil changes. This means that for a signal with twice the frequency, the output signal is twice as great for the same degree of magnetization of the tape. It is therefore necessary to compensate for this increase in signal to keep high frequencies from being boosted by a factor of two for each octave increase in pitch. This compensation process is called equalization.

问题：磁性乳液的磁化与记录的信号成正比，而线圈中的感应电压与线圈中磁化变化的速率成正比。这意味着，对于两倍频率的信号，相同磁化程度的磁带产生的输出信号强度是两倍。因此，必须对这种信号增强进行补偿，以防止高频信号因音调（pitch）每升高一个八度而被放大两倍。这种补偿过程称为均衡（equalization）。
Tape recording process
磁带录音过程
 Index

Sound reproduction concepts

Tape recording concepts

Reference
Rossing
Science of Sound
Ch 21
索引 声学再现概念 磁带录音概念 参考 Rossing 声学科学 第21章
 
HyperPhysics***** Sound
HyperPhysics ***** 声音
R Nave
 Go Back
返回