Assessments - 2, GPA: 3.5
(
)
)
|
Facilidade de uso
2.1: How a feedback loop is created A feedback loop is created when a microphone signal is first reproduced on an amplifier, and is then picked up again by the same microphone (with the same phasing). Then, it is amplified and reproduced again. This feedback loop may, under certain circumstances, keep on occurring and could escalate out of control. With P.A. applications, there are two major types of setups in which feedback can occur: ▲ Front mix (also called F.O.H. = “front of house”) refers to the mix being created when a signal from a mixing console is amplified by one or more power amplifiers and is fed into loudspeakers facing the audience. ▲ Monitor mix refers to the mix that also originates in the mixing console but ends up driving one or more stage monitors. Unlike FOH speakers, a stage monitor makes the music program audible to individual musicians. Please bear in mind that high volume levels can damage both your hearing and your equipment. Be sure to always select an appropriate volume level. 3. CONTROL ELEMENTS AND CONNECTIONS 3.1 The front Fig. 3.1: Control elements on FBQ2496’s left side IT! LEVEL METER The LEVEL METER lets you monitor the input level. Eight LEDs are available per channel. If the Clip LED lights up, digital distortion may occur on FBQ2496’s input. In this case, reduce the input level. l~2~l LEARN button A quick tap on the LEARN button (LED lights up) gets you into the lEaRN mode. The FBQ2496 will immediately start looking for critical frequencies and will deploy as many Single-Shot filters as necessary (of course, music or noise has to be present in the room for this to work). Besides, using the wheel \W\, you can manually determine the number of Single-Shot filters (max. 20 per channel). See ch.4.1. If you keep the LEARN button pressed for longer than one second (LED blinks), the FBQ2496 generates progressively louder impulses to generate feedback. The feedback thus created enters the FBQ2496 at its input, where it is recognized and suppressed. This mode is called AUTOLEARN (ch. 4.1). m PANIC If unexpected feedback starts occurring during a performance, pressing the PANIC button can help. As long as the button is kept pressed (for a maximum of 1 second), your FBQ2496 rapidly searches for feedback frequencies and suppresses them. m SPEECH Pressing the SPEECH button increases the sensitivity of feedback suppression; the FBQ2496 recognizes critical frequencies sooner and deploys a filter that cuts in appropriately. Unlike with feedback caused by a distorting guitar, human speech seldom produces signals that can mistakenly be identified as feedback. Therefore, this mode is ideal for situations in which only speech is being transmitted. Therefore, your P.A. system will be substantially louder. I~5l FREEZE Once a particularly good FBQ2496 setting is achieved, you can keep this setting by pressing the FREEZE button. All Single-Shot and automatic filters are kept at their settings until you press FREEZE again. l~6l FILTER LIFT The so-called “Filter Lifting Time” informs you about how long an adjusted automatic filter can remain inactive before its values are reset again. You can set this time by first briefly pressing the FILTER LIFT button and then turning the wheel. The following time lengths are available: 0 min, 1 min, S min, 10 min, 30 min, 60 min. 3. CONTROL ELEMENTS AND CONNECTIONS S FEEDBACK DESTROYER PRO FBQ2496 nn RESET If you briefly press the RESET button, all automatically set filters are erased. If you keep the RESET button pressed longer, Single-Shot filters are erased as well. In PEQ mode, briefly pressing the RESET button erases the selected filter. Keeping the RESET button pressed longer erases all the parametric filters all at once. rsi SssSii&sS Fig. 3.2: Status display and the LED display on the FBQ2496 C8] STATUS DISPLAY The FBQ2496 features a total of 40 filters, i.e. 20 filters per channel. They can be monitored and controlled on the STATUS DISPLAY. A constantly lit LED signalizes: ▲ A filter was deployed: It already suppresses an instance of feedback. or: ▲ A filter is in the Parametric EQ mode (PEQ), whereby gain has to be set to a value either higher or lower than 0 dB. A LED that only periodically blinks signalizes the selected filter in the PEQ mode. I~9~l LED DISPLAY The three-digit numeric display indicates the absolute value of the parameter you are modifying. How individual parameter are adjusted is explained in ch. 4. Hz or kHz is lit when you change the mid frequency of a filter. The min display is lit when you are adjusting the filter lift time. The 1/60 LED is lit when you select a filter value smaller than 0.1. In this case, you can select the following values: 1/60, 2/60, 3/60, 4/60 and S/60 (6/60 = 0.1). The df LED is lit when you adjust a filter gain value. The MIDI display briefly lights up as soon as the FBQ2496 receives MIDI data. Fig. 3.3: Control elements on FBQ2496’s right IT01 GAIN In the PEQ m...