AudioChainsDB
Sennheiser

HD 550

headphones

$229

Used market: $180*

Manufacturer datasheet

Specifications

4 of 7 values have a recorded source
Connector
3.5 mm + 6.35 mm adapter·
Form Factor
Over-Ear·
Is Closed Back
no·
Impedance ohms
150✓
Transducer Type
Dynamic·
Detachable Cable
yes·
Sensitivity dB V
106.7✓

Expert Audio Engineering Commentary

Tonal Profile

150 Ω open-back with a stated SPL to one decimal place — Sennheiser is the only maker in this batch that publishes sensitivity that precisely, and it does so per volt, which is the reference that actually matches how a source is specified.

Amplification Warning

150 Ω draws little current but wants voltage: about 0.3 V for 100 dB, which a laptop jack manages and a weak phone output may not with quiet recordings. This is the impedance at which the answer stops being «anything drives it» and starts depending on the source.

* Estimated with the depreciation fallback (~79% retained value). · checked on 8/5/2026