ResonantLive Sound Archive

Equipment file · Cardioid dynamic microphone

MD 421 microphone

Sennheiser · 1960

Evidence status · documented

Identity and core specifications are documented; some historical fields remain unavailable.

The Sennheiser MD 421, launched at the 1960 Hannover Fair, paired a large dynamic capsule with a closed housing that kept its directional pattern however it was held, plus a hum-compensating coil and a multi-position bass roll-off.

Introduced
1960
Category
Cardioid dynamic microphone
Intended use
Broadcast speech, recording and live vocals and instruments
Production
From 1960; capsule design largely unchanged for decades

Equipment photographs · 2

Sennheiser MD 421 ks01

1 / 2 · Sennheiser MD 421 ks01

Sennheiser MD 421 ks01·Kreuzschnabel·CC BY-SA 3.0

Why it mattered

  1. 01

    Its sealed body avoided the pattern loss that rear-ported directional microphones suffered when gripped.

  2. 02

    Its level handling and bass filter made it a standard for toms, guitar cabinets, brass and vocals on tour.

Engineering record

Frequency response
30–17,000 Hz[1]
Rejection and filtering
At least 16 dB front-to-back ratio, low-frequency roll-off filter and hum-compensation coil[1]

Original pricing

No reliable period price located

2026 equivalent

Not calculated without a reliable original price.

Public price evidence was not sufficient to publish a defensible original figure.

Use in the field

No named deployment could be tied to this exact item by a checked source yet. Know of one? Suggest it on the contribute page.

Manuals & original documents

Sources

  1. 1Sennheiser MD 421-U specification sheetSennheiser (archived) · manual
  2. 21960: Sennheiser MD 421Mix · reference · 2011
  3. 3Audio History: The Sennheiser MD 421 Microphone (1960)FOH · reference · 2024-10-03

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