Introduced in 1994, the Audio-Technica AT4050 represented an important development in the company’s professional studio microphone range. Following the success of the AT4033, introduced in 1991, Audio-Technica developed the AT4050 to provide greater versatility through selectable polar patterns while retaining the precision engineering and acoustic performance associated with the established 40 Series. The microphone was introduced at the 1994 European Audio Engineering Society convention in Amsterdam by musician, engineer and producer Alan Parsons, who became closely associated with its promotion.
The Audio-Technica AT4050 was developed at a time when high-quality large-diaphragm condenser microphones were becoming increasingly important in both professional and project recording studios. By combining multiple directional characteristics within a single microphone, Audio-Technica provided recording engineers with a flexible alternative to using several fixed-pattern microphones for different applications.
At the centre of the Audio-Technica AT4050 is an externally polarised, or DC-biased, dual-diaphragm condenser capsule. Unlike permanently polarised electret designs, the capsule receives its polarisation voltage from the microphone’s internal electronics. The dual-diaphragm configuration enables the microphone to provide three selectable polar patterns while maintaining accurate directional characteristics across its operating frequency response.
The capsule employs precision-manufactured, vapour-deposited gold diaphragms that undergo an ageing process designed to stabilise their mechanical properties. Audio-Technica developed this construction to maintain consistent sensitivity and polar pattern definition throughout the microphone’s operating life. The symmetrical capsule arrangement also contributes to the microphone’s acoustic performance by maintaining the relationship between sound arriving from different directions.
One of the defining characteristics of the Audio-Technica AT4050 is its selection of three polar patterns: cardioid, omnidirectional and figure-of-eight. These patterns are selected using a switch on the microphone body, allowing the recording engineer to adapt the microphone’s directional response to different instruments, acoustic environments and recording techniques.
In cardioid mode, the Audio-Technica AT4050 provides maximum sensitivity to sound arriving from the front of the capsule, with reduced sensitivity to sound from the sides and rear. This configuration is particularly suitable for close vocal recording, guitar amplifiers and individual instruments where separation from surrounding sound sources is required. The cardioid pattern also provides directional control when recording multiple musicians within the same acoustic space.
Selecting the omnidirectional pattern allows the microphone to capture sound arriving from all directions. This configuration is useful for recording acoustic instruments and ensembles where the surrounding room ambience forms an important part of the performance. Unlike directional patterns, the omnidirectional configuration does not exhibit the conventional proximity effect, allowing more consistent low-frequency reproduction when the microphone is positioned close to a sound source.
The figure-of-eight pattern provides sensitivity to sound arriving from the front and rear of the microphone while rejecting sound from the sides. This characteristic makes the Audio-Technica AT4050 suitable for recording techniques such as Mid-Side stereo, where a figure-of-eight microphone is combined with a forward-facing directional microphone to capture adjustable stereo information. It can also be used for recording two performers positioned on opposite sides of the microphone.
The Audio-Technica AT4050 incorporates transformerless output circuitry designed to minimise low-frequency distortion and preserve the accuracy of rapidly changing acoustic signals. By eliminating a conventional output transformer, the microphone avoids the magnetic saturation characteristics that can occur in transformer-coupled designs. This contributes to the accurate reproduction of instrumental transients and complex musical material.
The microphone’s frequency response extends from 20Hz to 18kHz, providing broad coverage of the audible spectrum. Audio-Technica designed the AT4050 to combine clear upper-midrange reproduction with extended low-frequency response, making it suitable for both vocal and instrumental applications. Its acoustic characteristics allow it to capture the detail of stringed instruments, the complex harmonic structure of piano and the transient behaviour of percussion.
For vocal recording, the Audio-Technica AT4050 offers the flexibility of selecting a cardioid pattern for focused pickup or an omnidirectional pattern when a more open acoustic presentation is required. The figure-of-eight configuration provides additional options for recording two vocalists or using the microphone as part of a stereo arrangement.
In piano recording, the Audio-Technica AT4050 can be positioned to capture the instrument’s wide frequency range and substantial dynamic variation. Its selectable patterns allow the recording engineer to control the balance between direct sound and room ambience, while its high sound pressure level capability accommodates the powerful transients produced during louder passages.
The microphone is also suitable for drum overheads, percussion and guitar amplifiers. Its maximum input sound pressure level is rated at 149dB SPL at 1kHz with 1% total harmonic distortion. Engaging the integral 10dB attenuation pad increases this capability to 159dB SPL, enabling the microphone to operate close to powerful sound sources without exceeding its specified input level.
A switchable high-pass filter operates at 80Hz with a slope of 12dB per octave. This provides a means of reducing unwanted low-frequency information before the signal reaches the microphone preamplifier. The filter can be used to attenuate environmental rumble, mechanically transmitted vibrations and excessive low-frequency energy associated with close microphone positioning. It can also be bypassed to retain the microphone’s full low-frequency response.
The Audio-Technica AT4050 provides an open-circuit sensitivity of -36dB, equivalent to 15.8mV at 1Pa. Its published dynamic range is 132dB, with a signal-to-noise ratio of 77dB at 1kHz and 1Pa. These characteristics allow the microphone to accommodate a broad range of acoustic levels, from relatively quiet instrumental passages to high-level amplified sources.
The microphone’s electronics operate from standard 48V phantom power, drawing approximately 4.2mA. Its balanced output is provided through an integral three-pin XLR connector, allowing connection to professional microphone preamplifiers, recording consoles and audio interfaces equipped with suitable phantom-power facilities.
The Audio-Technica AT4050 features a substantial cylindrical metal housing with a protective grille surrounding the condenser capsule. The housing is designed to provide an open acoustic environment around the diaphragm assembly while maintaining the mechanical durability required for professional studio and live sound operation.
Measuring 188mm in length and 53.4mm in maximum body diameter, the Audio-Technica AT4050 has a conventional side-address studio microphone configuration. Its 510g construction provides a stable enclosure for the capsule and internal electronics, with the polar pattern, attenuation and high-pass filter controls incorporated into the microphone body.
The Audio-Technica AT4050 is supplied with an Audio-Technica AT8449a shock mount designed to isolate the microphone from vibrations transmitted through the supporting stand. The suspension system reduces the transfer of mechanically generated noise to the microphone housing, particularly during recording situations where floor movement or stand vibrations may be present. A protective carrying case is also included.
Each Audio-Technica AT4050 is hand-assembled and individually inspected as part of the company’s quality-control process. The precision-manufactured dual-diaphragm capsule, selectable directional characteristics and transformerless electronics reflect the engineering approach established during the development of Audio-Technica’s professional 40 Series.
The introduction of the Audio-Technica AT4050 in 1994 marked an important stage in the company’s development as a manufacturer of professional studio microphones. Endorsed by Alan Parsons and adopted for a broad range of recording applications, the Audio-Technica AT4050 expanded upon the success of the original AT4033 by introducing multi-pattern versatility. Its continued production reflects the longevity of the original design, which remains part of Audio-Technica’s professional microphone range more than three decades after its introduction.
Features
- Professional large-diaphragm multi-pattern condenser microphone introduced in 1994
- Externally polarised dual-diaphragm condenser capsule with precision-manufactured gold-coated diaphragms
- Three selectable polar patterns: cardioid, omnidirectional and figure-of-eight
- Dual-diaphragm design maintains accurate polar pattern definition across the operating frequency response
- Transformerless output circuitry for reduced low-frequency distortion and accurate transient reproduction
- Extended 20Hz to 18kHz frequency response suitable for vocal and instrumental recording
- Wide 132dB dynamic range for recording sources with substantial variations in sound pressure
- High sound pressure level handling up to 159dB SPL with attenuation engaged
- Switchable 80Hz high-pass filter and 10dB attenuation pad
- Hand-assembled construction with 48V phantom-powered operation and supplied AT8449a shock mount