AEA KU4 Unidirectional Ribbon Microphone AEA

The KU4’s supercardioid polar pattern enables it to capture direct sound from a vocalist or instrument without room tone. This is an advantage when tracking musicians live in the same room or when used live on stage. With most figure-of-eight patterned ribbons, mic positioning can require a finesse to avoid other sources using the microphone’s nulls. The KU4 has none of these limitations.

Being a near-field ribbon microphone, the microphone was designed to be positioned between one and 18 inches from the source. The mic’s proximity effect kicks in six inches away from the sound source. It can be placed close to an instrument while retaining a balanced frequency response.

Unlike most traditional ribbon mics, think the KU4’s placement should be thought in terms of inches instead of feet. Of course, the KU4 can also be positioned at some distance from the sound source. It will just have a more balanced sound from up close.

The KU4 can handle 140+ dB SPL at 1 kHz. That means it will not be hurt by loud sound sources.

A REINVENTION OF A CLASSIC MOTION PICTURE MICROPHONE

The KU4 is a redesign of the legendary RCA KU3A, a unidirectional microphone originally designed for boom use in Hollywood motion picture studios. It was RCA’s most expensive ribbon microphone and fewer than 600 units were ever manufactured.

The KU3A combined the smooth ribbon sound of the classic RCA 44 with a unidirectional pattern, a wide sweet spot, and reduced proximity bass boost. It expanded the engineer’s range of placement choices and became a standard at film studios throughout the world.

Today, the KU3A is a rare collector’s item and only a handful of studios or rental houses own them. Original KU3As are notorious for their sonic inconsistencies due to production tolerances that included the use of the thick hair of English cows as a damping material.

At AEA, we engineered our KU4 from the ground up in order to recreate this seminal design while ensuring flawless consistency from unit to unit.

Since the KU4 is a classic passive ribbon microphone, the preamp is critical for optimum performance. Preamp gain should be at least +60dB or higher and the preamp should have a very high impedance. It’s the same requirement with all passive ribbon mics.

To guarantee consistent, full-range ribbon sound, we recommend AEA’s RPQ2, RPQ500 and TRP2 preamps, which were specially designed for ribbon microphones. However, preamps with above a 5K ohm impedance found in many live soundboards are adequate for guitar amps and other louder instruments. On quiet sound sources or for distance recording, an AEA preamp is highly recommended.

KU4 MICROPHONE OVERVIEW