ResonantLive Sound Archive

Equipment file · Cardioid dynamic microphone

MD 409 microphone

Sennheiser · 1960s

Evidence status · documented

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

The Sennheiser MD 409 is a flat-faced cardioid dynamic microphone designed for close-miking loud instrument amplifiers; its shape let it hang directly in front of a speaker cone. Sennheiser lists 50–15,000 Hz response and 200-ohm impedance.

Introduced
1960s
Category
Cardioid dynamic microphone
Intended use
Guitar amplifiers and vocals
Production
Sennheiser; succeeded by the BF 509 and e 609

Why it mattered

  1. 01

    It became known as one of the best guitar-cabinet microphones of its era and was also used for live vocals.

  2. 02

    Its flat front led to Sennheiser's later guitar microphones such as the e 609.

Engineering record

Frequency response
50–15,000 Hz, cardioid[1]
Sensitivity and impedance
1.18 mV/Pa at 1 kHz, 200 ohms, XLR[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

Pink Floyd's live vocal microphone, seen in Live at Pompeii[2]

Manuals & original documents

Sources

  1. 1MD 409 U-3 Dynamic MicrophoneSennheiser · manual
  2. 2From the MD 409 to the e 609Sennheiser · archive

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