User manual AKG D 770

[. . . ] the wide frequency response of the D 770 slightly favors the midfrequency and treble regions and thus ensures good intelligibility. Having a cardioid polar response, the D 770 is most sensitive to sound arriving from in front of it, less sensitive to sound arriving from the sides, and least sensitive to sound arriving from the rear. this polar pattern is virtually the same for all frequencies ("frequency independent"). [. . . ] 1 Proximity Effect Please note that moving the microphone closer to the instrument will boost the bass range of the microphone signal. Using this effect, you can create your personal sound by varying the working distance. Feedback is the result of part of the sound projected by a speaker being picked up by a microphone, fed to the amplifier, and projected again by the speaker. Above a specific volume or "system gain" setting called the feedback threshold, the signal starts being regenerated indefinitely, making the sound system howl and the sound engineer desperately dive for the master fader to reduce the volume and stop the howling. to increase usable gain before feedback , the microphone has a cardioid polar pattern. This means that the microphone is most sensitive to sounds arriving from in front of it while picking up much less of sounds arriving from the sides or rear (from monitor speakers for instance). To maximize gain before feedback, place the main ("FOH") speakers in front of the microphones (along the front edge of the stage). Be sure never to point any microphone directly at the monitors, or at the FOH speakers. Feedback may also be triggered by resonances depending on the acoustics of the room or hall. With resonances at low frequencies, proximity effect may cause feedback. In this case, it is often enough to move away from the microphone a little to stop the feedback. For popular and jazz pieces, relatively short distances may be desirable (1 or 2 in. ), as the amount of wind and breath noise rises with decreasing working distance. In this case, blow a little below the microphone in order to avoid getting too much noise by blowing at it from an extremely short distance. For classical music, which calls for spatial reproduction, place the microphone about 4 to 8 inches away from the instrument and slightly above it. If you consider the noise produced by the keys as characteristic of the saxophone sound or the song, point the microphone at the middle of the instrument. However, if you want no key noise, direct the microphone toward the front outer rim of the bell. If you aim the microphone into the bell, you will get too much wind noise. [. . . ] If the two vocalists were to sing into the microphone from a wider angle than 35 degrees, you may end up bringing up the fader of the microphone channel far enough to create a feedback problem. SPL for 1 % / 3 % THD: Equivalent noise level: Environment: Connector: Connector pinout: dynamic pressure gradient microphone cardioid 60 to 20, 000 Hz; 20 to 20, 000 Hz at 1 cm 2. 5 mV/Pa (­52 dBV re 1 V/Pa) 600 2000 147 dB SPL / 156 dB SPL 22 dB (A) (DIN 45412) temperature: ­10°C to +60°C rel. [. . . ]