At the 2010 San Francisco AES show AEA unveiled the KU4 unidirectional ribbon microphone.
The KU4 is AEA’s modern interpretation of the original RCA KU3A, which many engineers consider to be the best ribbon microphone ever made.
The increased rear rejection of the supercardioid pattern reduces the amount of room sound, which is often desired in modern production applications, particularly vocal recording.
The KU4 celebrates the legendary RCA unidirectional KU3A, a highsensitivity microphone designed for the Hollywood movie studios. Also known as a M-10001 for its manufacturing number, it was RCA’s most expensive ribbon microphone. Fewer than 600 were ever manufactured.
The KU3A combined the ribbon sound of a 44 with a unidirectional pattern, a wide sweet spot and less proximity bass boost, expanding an engineer’s range of placement choices.
Although condenser mics became the new standard by the end of the 1960s, ribbon mics are still appreciated today by experienced music recording engineers. However the KU3A is a rare microphone, a collector’s item, and few studios or rental houses own them. Opportunities to work with a good KU3A are limited.
We are proud to expand your opportunities with the AEA KU4 featuring an RCA ribbon, interchangeable KU3A parts and consistent performance.
The KU4 is different from other ribbon microphones in a number of areas. The suppressed rear lobe is useful when the back of a figure-of-eight would pick up undesirable sounds and reduced proximity bass boost facilitates closer micing.
Additionally, its low-tuned ribbon delivers solid, undistorted bass. These characteristics make the KU4 well suited for modern studio production.
Its lightly-tensioned, ultra low mass ribbon has a frequency response out to 40 kHz and fast, accurate transients. The KU4’s ribbon is well protected and its field-tech replaceable pole piece and ribbon assembly is a ideal should an accident occurs.
Operating Principle: Velocity microphone
• Frequency Response: Below 30 Hz to above 20 kHz
• Maximum SPL: 140 + dB SPL above 200Hz for 1% third harmonic
• Output Sensitivity: 2.8 mV/Pa into unloaded circuit
• Output Impedance: 300 Ω nominal
• Recommended Load: 1.2 KΩ or greater
• Phantom power: Not required or recommended
• Polarity: Pin 2 high for positive pressure at the front of the microphone.
• Connector: XLR-3M wired to a 1.5 meter captive cable
Off Axis Response:
• Polar Pattern: Supercardioid
• Relative Output at 180° (dB): -12
• Angle of Maximum Rejection: 135°
Transducer element
• Ribbon Thickness: 1.8 microns ( .0000018 meter ) of pure aluminum
• Ribbon Width: 0.082” (2.1 mm)
• Ribbon Length: 1.25” (28.6 mm)
Accessories:
• Included: Custom storage/shipping case, stand adapter, manual and
attached 1.5 meter microphone cable
