The AKG D19 was a cardioid dynamic microphone manufactured by AKG in the 1960s. It is famous today for its use at Abbey Road studios during numerous Beatles recording sessions, most notably as a drum overhead mic for Ringo Starr. The AKG D19 has a mechanical high-pass filter which is continuous, ranging from 0 to -10dB at 50Hz.
The published frequency-response graph shows a nominally flat response from 70Hz–1500Hz, with a broad presence peak of +4dB from 3kHz–10kHz.
The D19 has a Cardioid pickup pattern which is relatively consistent below 1kHZ, with a -10dB drop in sensitivity at 90° below 250Hz. It is worth noting that although most microphones tend towards omnidirectional at low frequencies, the D19 instead becomes more directional. Rear rejection is strong at all frequencies.