Behringer user manual Setting up the B415DSP, Tweeter, How to avoid feedback, Off

EUROLIVE B415DSP

The TIMED TURNOFF switch activates the automatic turn- off function:

ON

When the switch is actuated (ON position), the automatic turn-off function is active. The loudspeaker is turned off automatically when it receives no signal for more than 3 minutes. As soon as a signal is received, the loudspeaker is switched back on.

OFF

If the switch is not actuated (OFF position) then the speaker remains switched on and can only be deactivated via the POWER switch .

A noise-gate allows you to eliminate unwanted noise during signal pauses. This is done by a circuit that mutes the output when the signal level drops below a preset threshold. Use the NOISE GATE control to determine the threshold below which the noise-gate closes.

The TH LED lights up as soon as the signal level drops below the threshold value adjusted with the NOISE GATE

control (the noise-gate closes).

The LED on the front indicates the following operating status:

Indicator	Operating status
BLUE light	The device is switched on
BLUE light	Device is on standby
(dimmed)	(if TIMED TURN-OFF activated)
	￿￿￿
VIOLET light	same function as CLIP LED
flashing RED	Device is overheating!
	Switch off the speaker until it cools down
Tab. 2.1: Frontal LED operating status

3. Setting up the B415DSP

The sound of your B415DSP largely depends on the room acoustics. Please observe the following hints to get the most out of your B415DSP.

3.1 Tweeter

High frequencies are the very part of the audio spectrum that ensure a clear perception of sound and speech intelligibility. Although these frequencies can be located most easily, they are also the first to be blocked acoustically. We therefore recommend that you set up your speakers on speaker stands (not included), so that the tweeter radiates its signals slightly above the heads of the audience. This will ensure both an optimum dispersion of the high-frequency content and a considerably improved speech intelligibility.

Fig. 3.1: B415DSP mounted on a stand

3.2 How to avoid feedback

Always place the microphones (viewed from the audience) behind the B415DSP, never in front of it (Fig. 3.2). When you wish to adjust the controls on the B415DSP while holding a microphone, please approach the loudspeaker from the rear to avoid feedback.

Fig. 3.2: Right and wrong positioning

Since the B415DSP can be placed on the floor at an angle as shown in the illustration below, you can also use it as a monitor speaker on stage. In contrast to PA speakers, stage monitors are used to direct sound towards individual performers on stage. When microphones are used, it is not easy to position the monitor speakers, since the microphones are moved around in front of them, often coming very close. To avoid feedback, it is recommended that you carefully select and direct the microphones used. Basically, you should use microphones with a high directivity, i.e. with a cardioid or hyper-cardioid polar pattern. Never hold a microphone so that its main pick-up area points directly towards the loudspeaker. When you hold it with its less sensitive side towards the speaker box, you can move closer to the speaker.

Microphones with a cardioid polar pattern should always be directed at a 90° angle to the axis of the loudspeaker (Fig. 3.3, left). Microphones with a hyper-cardioid polar pattern should always be positioned at an acute angle to the axis (Fig. 3.3, right).

Fig. 3.3: The B415DSP as a monitor loudspeaker

+If you encounter persistent feedback problems, consider using our proven FEEDBACK DESTROYER PRO FBQ2496 for line-level signals. For signals with line or microphone level, we recommend our BEHRINGER SHARK DSP110.

3. Setting up the B415DSP 7