Glossary
Impedance
A headphone's electrical resistance to AC current, in ohms (Ω). Low-impedance (16–80 Ω) headphones run loud from any phone; high-impedance (250–600 Ω) need a dedicated amplifier.
Impedance determines how much voltage is needed to drive a headphone to a given volume.
Categories
- 16–32 Ω — IEMs, most consumer cans. Run loud from a phone.
- 32–80 Ω — premium portable headphones. Phone works; dedicated amp adds headroom.
- 150–250 Ω — studio/Hi-Fi (DT 770, HD 600 family). Need a real amp.
- 300–600 Ω — pro studio. Definitely need an amp.
Why high-impedance exists
Higher-impedance drivers can be wound with thinner wire, allowing tighter motor systems and more accurate transient response — at the cost of needing more voltage to drive.
Sensitivity matters too
A 32 Ω headphone at 85 dB/mW sensitivity may be quieter than a 300 Ω one at 110 dB/mW. Always read impedance + sensitivity together.
Where this matters
Categories that use impedance
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