The AKG Model C 451 B
Studio Cardioid Condenser Microphone
The C 451 B is an updated rerun of a classic AKG condenser microphone, the C 451 EB + CK 1. The new C 451 B, however, uses a fixed capsule to eliminate the mechanical problems of the original modular design. The microphone is the perfect choice for any application where sounds, particularly their transient content, need to be captured with maximum accuracy.
Owing to its extremely light diaphragm, the microphone is highly insensitive to handling noise. An all-metal body provides efficient protection from RF interference, and the microphone is rugged enough to give excellent results even under harsh conditions.
A switchable high-pass filter at 75 Hz or 150 Hz prevents low-end distortion that may be caused, e.g., by rumble or wind noise. The slope of the filter is 12 dB/octave and its corner frequency (3 dB down point) is selectable at 75 Hz or 150 Hz.
A switchable 10-dB/20-dB preattenuation pad increases the microphone’s SPL capability when close-miking high-energy sound sources or driving preamps or mixers with limited headroom.
The C 451 B is the latest model in the C 451 series that dates back to 1969. It is a cardioid only design with a permanently fixed capsule (a departure from the previous modular system). The acoustics of the original cardioid capsule, CK 1, are modeled and matched in the current version, producing the unique overall rising frequency characteristics. The rise is no more than 3 dB and is broadly centered around 12 kHz.
Its transformerless preamp uses surface mount technology and, therefore, is lighter, yet more rugged than its predecessor. Switchable 10 and 20 dB pads are now integrated. Maximum sound pressure levels in the range of 155 dB (in the 20 dB sensitivity position) can be attained with no greater than 0.5% distortion. A selectable low frequency, or bass roll-off option, provides 12 dB per octave attenuation below 75 or 150 Hz.
The C 451 B, like its predecessor, is most commonly used in studio and tour sound applications such as miking choirs, drums, percussion and acoustic guitars. It is available as a single piece or in computer-matched stereo pairs, and operates on all phantom voltages between 9 and 52 volts.
Text and illustrations are taken from the two downloadable documents that are available below.
Download the Description of this mic.
Download the Instructions for this mic.
(Multi-lingual, including English.)