User manual AEA R88

[. . . ] Our ribbon transducers are tensioned very lightly, so that coupled air damping provides excellent transient response. To help ensure a long life and consistent sound keep the microphone stored vertically whenever possible to prevent "sagging" that may occur during long term horizontal storage. Using a correctly wired cable and a decent phantom power supply, there is little danger of damaging the microphone with phantom power. [. . . ] This means that the microphone can operate with very low distortion throughout a huge dynamic range. However the passive design also means that a large amount of gain is often required at the preamplifier stage. Low preamp noise specs are desirable, since the preamp will often need to be operated at its highest gain settings. As a starting point, here are a few specs to look for in a mic preamp to use with your R88: - Abundant gain (at least 60dB of clean gain, quiet recordings may require up to 70dB) - Low noise (EIN -127dB or better) - High input impedance (we suggest at least 1. 5 kOhm for good bass performance) Coincident Stereo Microphone Techniques The R88 is a coincident stereo microphone system. Coincident microphone techniques use two or more microphones placed as closely together as possible, but aimed in different directions. Coincident stereo recording systems have phase coherence between the stereo channels. This means that an incoming sound wave arrives at roughly the same time to both of the microphone transducers. The R88 may be used with "Blumlein" or "M-S" stereo techniques. There are other stereo recording techniques generally referred to as spaced stereo techniques, where the microphones used are physically separated in order to produce timing differences between the microphones. One advantage of phase coherence is that when listening to a mono sum of the stereo mix, or to a stereo playback in the "far field, " a phase coherent recording will exhibit much less of the coloration known as comb filtering. Comb filtering occurs because spaced microphones necessarily capture different phase information depending on the difference in path length from each sound source to each microphone. When the stereo channels are added together comb filtering will appear as "holes" in the frequency response. Moreover these aberrations in frequency response depend on the angle of sound incidence, so equalization alone cannot correct comb filtering problems. Some engineers prefer spaced stereo recording techniques regardless of potential mono summing problems, because of the impression that the stereo field produced is "wider" and more "enveloping. " Obviously any singlehousing stereo microphone system employs a coincident (or near-coincident) micing technique. [. . . ] M-S decoding is very easy to implement in software, and several developers offer M-S decoding tools in popular plug-in formats. NOTE: This is a working document. For the latest revision of the R88 Users Manual please visit: http://www. wesdooley. com. Copyright © 2004, Audio Engineering Associates. References and Recommended Reading: BASIC STEREO MICROPHONE PERSPECTIVES - A REVIEW, first published in the AES Journal, vol. [. . . ]