Impedance
AC resistance — mismatch costs highs
Related
Impedance is the total opposition to alternating current, combining resistance, inductance and capacitance. In audio the common issue is matching input and output impedance: a high-impedance instrument such as a guitar needs a high input impedance, or it loses highs and thins out.
It differs from resistance: resistance applies to DC/low frequencies, impedance varies with frequency; it differs from level too: impedance does not set loudness, it decides whether the signal transfers correctly. The usual mistake is to think bigger impedance is always better — matching matters more than size; the input impedance of a DI and preamp exists for exactly this.
Read deeper → DI box
Sources
- 阻抗匹配与乐器信号的通行原则，参通行录音教材；本文为原创表述
Used for fact-checking only; all prose is original.