Electro-Voice RE20
A broadcast dynamic that behaves like a condenser, weighs as much as a small hammer, and refuses to be moved off-axis.
Overview
The RE20 weighs 737 grams - a pound and ten ounces - and that is the first thing anyone notices when they pick one up. The weight is not decoration. The case is steel, and inside it Electro-Voice built a hum-bucking coil alongside the element. The company rates hum pickup at -130 dBm in a 60 Hz field of one millioersted. Next to a monitor wall or a studio full of CRT displays, that shielding is the difference between a usable microphone and a paperweight. E-V credits the steel housing and a mechanical nesting concept for the RE20's handling-noise rejection and its reputation for surviving professional abuse.
The element is dynamic, and the RE20's whole pitch is making a moving-coil microphone act like something it isn't. E-V's own documentation describes a large Acoustalloy diaphragm paired with an exceptionally low-mass aluminum voice coil. It claims the resulting transient response is comparable to the finest condenser cardioids, with no phantom power needed and effective immunity to overload. A condenser will distort when the SPL exceeds its electronics. The RE20 keeps working, and E-V specifies that it will continue to function in high humidity and elevated temperatures that would degrade phantom-powered condensers.
The frequency response is specified as 45-18,000 Hz, and the shape of that curve is why the microphone became a broadcast fixture. With the filter switch off, the manual describes the RE20 as essentially flat from 80 Hz to 6 kHz, with a broad 2.5 dB rise between 6 and 14 kHz, nominally down 3 dB at 18 kHz, and down 3 dB at 45 Hz below the 80 Hz mark. That presence lift is why voices cut through a mix without equalization. Flip the switch on and an integral passive network tilts the low end down 4.5 dB from 400 to 100 Hz. It is a bass-tilt-down control intended for long-reach situations or any application where the bottom needs trimming. Sensitivity is 1.5 mV/Pascal, nominal impedance is 150 ohms balanced, and pin 2 goes positive referenced to pin 3 under positive diaphragm pressure.
The pattern is a true cardioid, and E-V is specific about what that means. Rejection is greatest at 180 degrees off axis, directly to the rear. It exceeds 15 dB from 45 Hz to 10 kHz and exceeds 13 dB above 10 kHz. The manual also states that response at any angle away from the major axis is essentially similar to the on-axis response, uniformly attenuated by the amount appropriate to that angle. E-V's phrasing is a cardioid of revolution, with virtually no off-axis coloration. A show host who turns their head while talking, or a vocalist who won't stand still, gets the same sound either way.
Then there is Variable-D. The RE20 uses a dual-ported, continuously Variable-D design, and the point of it is to kill the proximity effect, the bass boost most directional microphones produce when worked close. E-V's documentation is direct about the result: the RE20 can sit very close to a source without losing clarity or definition. Singers can close-talk with lips nearly touching the grille. An integral blast and wind filter covers every acoustic opening and handles the P-pops and sibilance that would otherwise ruin the take. That same filter also shock-mounts the internal element, reducing vibration transfer from stands and booms. The mic works inside a bass drum, on an acoustic guitar, and in a voice booth.
Physically, the RE20 measures 216.7 mm long, 54.4 mm at its widest diameter, and 49.2 mm at the body. The finish is a nonreflecting fawn beige. A shield keeps dust and iron particles off the diaphragm. An 81715 stand clamp ships with the microphone. The optional 309A shock-mounted stand adapter is the one to hunt for if the mic lives on a floor stand or a recording boom. Shipping weight is 1,474 grams.
The archive does not have a documented production start date, an original list price, or independent lab measurements for the RE20. The available manufacturer documentation carries a 2006 Telex Communications copyright, which means the design was still in catalog then but says nothing about when it began. The secondary market is active and pricing varies, so this archive does not quote a number it cannot verify. Contemporary coverage in the audio press, such as Mix (January 1998, p.174), discussed specialized drum microphones like the Electro-Voice N/D868.
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