AKG Acoustics
AKG C 391 B
Small-diaphragm condenser, cardioid: the SE 300 B powering/output module with the screw-on CK 91 capsule (Blue Line modular system)
Power Phantom, 9 to 52 V (IEC 61938).
- Type
- Condenser (electret)
- Pattern
- Cardioid
- Sensitivity
- −40 dBV/Pa
- Among 204 condensers: more output than 33%
- Among 311 mics: more output than 53%
- Self-noise
- 17 dB(A)
- Among 258 condensers: quieter than 40%
- Among 272 mics: quieter than 41%
- Max SPL
- 132 dB SPL
- Among 277 condensers: takes louder sound than 26%
- Among 343 mics: takes louder sound than 24%
- Rated range
- 20 – 20k Hz
vs 75 end-address condensers
More output than 20% of 75 end-address condensers.
Each stripe is one end-address condenser with a published sensitivity, and each bar counts them; further right means more output. This mic is in blue.
vs 104 end-address condensers
Quieter than 43% of 104 end-address condensers.
Each stripe is one end-address condenser with a published self-noise, and each bar counts them; further right means quieter. This mic is in blue.
vs 110 end-address condensers
Takes louder sound than 17% of 110 end-address condensers.
Each stripe is one end-address condenser with a published max SPL, and each bar counts them; further right means it takes louder sound. This mic is in blue.
Proximity effect: the bass it gains up close
From the manual, p. 21.
"Frequency Response Curve"; relative dB. Distance, field and smoothing not stated.
Dashed: outside the rated range, or simulated (other angles and distances). Hover or tap the graphs for values.
Polar pattern
From the manual, p. 21.
"Polar Pattern"; 125 Hz to 1 kHz on the left half, 2 to 16 kHz on the right; 0° at the bottom, rings every 5 dB, centre -25 dB.
In practice
All specs
| From the manual | ||
|---|---|---|
| Capsule | CK 91 cardioid capsule on the SE 300 B module (bayonet mount, interchangeable) | p. 14 |
| Sensitivity | −40 dBV/Pa (10 mV/Pa)at 100 Hz (as printed). "Field open loop gain (sensitivity) at 100 Hz: 10 mV/Pa - 40 dBV"; every language says 100 Hz, where 1 kHz is usual. | p. 20 |
| Self-noise | 17 dB(A)IEC 60268-4, A-weighted | |
| Max SPL | 132 dB SPL1000 Hz. "Sound pressure limit: 80 Pa (132 dB) for 1000 Hz"; no distortion figure given. | |
| Signal-to-noise ratio | 77 dBre 1 Pa, A-weighted | |
| Output impedance | 200 ohm | |
| Rated load impedance | 1000 ohmrecommended | |
| Rated frequency range | 20 Hz to 20 kHz± 2 dB from the nominal curve | |
| Powering | phantom, 9 to 52 V (IEC 61938) | |
| Current draw | 2 mA"Current consumption: 2 mA" (the sign before 2 is lost in the PDF text; probably "<"). | |
| Low cut | off, 75 Hz; 75 Hz; 12 dB/octave"The filter slope is approx. 12 dB/octave with the corner frequency (-3 dB point) lying at approx. 75 Hz"; p. 14 says the onset is at about 100 Hz. | p. 16 |
| Pad | −10 dB"Integrated, switchable 10 dB attenuation of gain". | p. 14 |
| Connector | XLR-3 male"Type XLR-3 acc. to IEC". | p. 20 |
| Weight | 115 gnet, approx. | |
| Dimensions | 19 × 147 mmDiameter × length. | |
| Finish | mat grey (brass housing) | |
| Supplied accessories | W 90 foam wind guard; SA 60 universal stand connectorScope of supply. | p. 14 |
| Acoustic working principle | Pressure gradient receiver | p. 20 |
| Operating conditions | -20 °C to +60 °C; relative humidity 99% (+20 °C), 95% (+60 °C) | |
| Output stage | Transformerless | p. 14 |
| Other capsules for the SE 300 B | CK 92 omni, CK 93 hypercardioid, CK 94 figure-eight, CK 97C miniature cardioid, CK 98 short shotgun | p. 17 |
| Optional accessories | A 91 articulated joint (±90°), B 18 battery supply, H 30 elastic suspension, ST 45 / ST 46 / ST 305 table stands | p. 15 |
Documents
- C 391 B / SE 300 B user instructionsGerman, English, French, Italian, Spanish, Portuguese
Copies kept by Mic Archive (manufacturers move and drop their documents). Each is © AKG Acoustics, unchanged, with its original address.