The No.1 Website for Pro Audio


The Type 44-BX Velocity Microphones (MI-4027-B, -D, -H, -J and -K) are high-fidelity micro*phones of the ribbon type that are specially designed for broadcast studio use. They are constructed to withstand mechanical shocks, and to retain sensitivity and frequency response regardless of changes in temperature, humidity, and barometric pressure. Their essentially flat frequency response (50 to 15,000 cycles) is suitable for reproducing both voice and music. The moving element of the micro*phone is a thin corrugated aluminum ribbon sus*pended be*tween the poles of a strong Alnico magnet. The moving air particles that constitute sound waves vibrate the ribbon in the magnetic field. This motion causes an alternating voltage to be generated in the ribbon, the amplitude of which is pro*portional to the velocity of the air particles. The output voltage and the electrical impedance of the ribbon are raised to a value suitable for transmission of the signal to an amplifier, by a transformer built into the micro*phone case. The transformer is well shielded against stray magnetic fields by multiple shields of mu-metal and copper. Directional Pattern One of the most useful properties of a velocity micro*phone is its bi-directional or figure-eight directional characteristics. As shown in the directional patterns (figures 2 and 3), the output of the micro*phone is maximum for sounds originating directly in front of or behind the micro*phone, and minimum for sounds originating at the sides, top or bottom. This characteristic is valuable for both vocal and musical pickup. For vocal pickup, its chief value lies in the fact that it enables participants in dialog to face each other across the micro*phone. For musical pickup, it makes it possible to obtain different effects by arranging orchestral instruments about the micro*phone so that the sounds of some instruments are attenuated and others are accentuated. The directional pattern also makes it possible to eliminate acoustic feedback from loud*speakers, which occurs frequently in sound-reinforcement work. In addition, the directional pattern reduces pickup of background noise and reflected sounds. For the same ratio of reverberatory to direct pickup, a sound source can be placed 1.73 times as far from a bi-directional micro*phone as from a non-directional micro*phone.


2009: Show us your mic locker.

Not shown: Neumann CMV-563, Ela M-251, RCA 44BX, Royer 121, one of my MD409U3s, my MD409N, about twelve D19c / D19b / D24 / D119s, plus SM57s.

View Post

Why use ribbon mics?

First off, not all ribbons are created equal. In a sparse arrangement, an RCA 44bx can capture acoustic guitar in a huge, intimate and very pleasing way. Check out Peter Mulvey's latest. Recorded at Ani Difranco's home studio, U47 on vocals, RCA44 on guitar: Are You Listening? by Peter Mulvey on Apple...

View Post

Songs of Leonard Cohen

Thank you very much for sharing. I'm attempting to build my bedroom studio here with analog gear - DAW's and me can't get along! So I got a TEAC tape deck and have been playing into that, been too much fun. Now I'm just looking into tube preamps, eyes focussed on the LA 610 mkii....

View Post