SA-300

Stage Amplifier

Q.I understand that the SA-300's anti-feedback setting can be made quickly and automatically. How does this actually work?

A.The SA-300's Anti-Feedback function is a unique Roland design, and is very easy to use. After setup, simply press a button to generate a short series of test tones, and the system calibrates itself automatically.

Anti-Feedback Calibration

Fixed microphone position

Use the following procedure to calibrate the Anti-Feedback function when you're using a mic in a fixed location during your performance (e.g., mounted on a mic stand):
  1. Set up and connect the SA-300 and your mic.
    • Set up the SA-300 and mic in the positions where you want to place them.
    • Adjust the height of the mic stand and the angle of the mic.
    • Set the SA-300's VOLUME knob to the volume that you will use while performing.
  2. Press the ANTI-FEEDBACK [ON/OFF] button so its indicator lights.
  3. Press and hold the ANTI-FEEDBACK [SWEEP] button for one second or longer. The indicator will flash, and a series of test tones ("pi, pi, pi-pi, piuun") will sound. The test tones are set automatically according to the position of the mic and the volume setting.
    • Be aware that if the volume is raised, this process will produce a fairly loud sound.
    • To ensure an accurate calibration, please keep the environment as quiet as possible during this process.
    • Don't stand in front of the mic during the calibration process.
    When measurement and analysis are finished and feedback prevention processing has been completed, the indicator will change from flashing to lit solid.

Handheld mic

If you'll be holding the mic in your hand during your performance, the acoustic response of the mic (in relation to the environment) will be constantly changing. Use the following procedure to calibrate the Anti-Feedback function for a handheld mic:
  1. Press the ANTI-FEEDBACK [ON/OFF] button so its indicator lights.
  2. Set up and connect the SA-300 and your mic.
    • Set the SA-300's VOLUME knob to the level that you will use while performing.
    • In order to analyze the response of the mic as accurately as possible, locate the mic position as shown in the following diagram, either by holding it in your hand or by using a mic stand.
      During this setting, be aware that feedback will occur if the mic is pointed at the speaker (or too close to it).
      (1) Angle: directly in front of the SA-300
      (2) Distance: about 50 cm
      (3) Height: at least 120 cm (the height for actual use)
      (4) Mic direction: horizontal in the direction of the SA-300

  3. Press and hold the ANTI-FEEDBACK [SWEEP] button for one second or longer.
    The indicator will flash, and a series of test tones ("pi, pi, pi-pi, piuun") will sound. The test tones are set automatically according to the position of the mic and the volume setting.
    • During calibration, don't allow your body or any object to come between the mic and the SA-300.
    • To ensure an accurate calibration, please keep the environment as quiet as possible during this process.
    When measurement and analysis are finished and feedback elimination processing has been completed, the indicator will change from flashing to lit solid.
    Circumstances that will cause the calibration to fail
  • If a mic is not connected or if the volume is too low when you press the [SWEEP] button to begin calibration, an error tone will sound and the analysis will be halted. If this occurs, please check the connections and settings.
  • If there is too much noise in the environment or if the mic is too far away when you press the [SWEEP] button to begin calibration, an error tone will sound and the analysis will be halted. In this case, the SWEEP indicator will not light.
  • If you press the [ON/OFF] button while the SWEEP indicator is lit, the indicator will go dark and the Anti-Feedback function will be turned off. However, when you press this button again, the compensation settings will return to their previous state.

    Notes about the Anti-Feedback function
  • The SA-300's Anti-Feedback function applies only to the MIC inputs on CH 1 and CH 2 (it does not work on the LINE inputs).
  • The calibration settings are discarded when you turn off the POWER switch.
  • The operating panel will not respond while the SWEEP test is being performed. (If you operate the panel during the SWEEP test, the results will be applied after the test has ended.)
  • Applying the Anti-Feedback function will slightly affect the tonal character.
  • In some situations, feedback may not be suppressed even if the feedback prevention process initiated by the SWEEP button has been completed.

(2006/03/27)

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