Bosch LBB 1968 User Manual download pdf

Communications Systems | LBB 1968/00 Plena Feedback Suppressor

LBB 1968/00 Plena Feedback Suppressor

www.boschsecurity.com

u Patented feedback suppression algorithm

u Suppresses feedback before it occurs

u Automatically adapts to the acoustical situation

u Up to 12 dB additional gain before feedback occurs

u Balanced line or microphone input with phantom

supply

The Plena feedback suppressor uses a powerful DSP

with a patented algorithm to suppress acoustic

feedback. It actively filters out unwanted room

reverberations using an echo-cancellation and de-

reverberation algorithm. By adding masked (inaudible)

noise to the output signal or by shifting the frequency

of the output signal by five hertz, the Plena feedback

suppressor is able to detect the reverb component of

the signal and remove it before feedback occurs. This

leaves the original signal intact.

Functions

The adaptive filter can be switched between fast mode

and accurate mode. The fast mode is for situations

where the microphone position changes over time,

such as in a discussion system with multiple switching

microphones. The accurate mode is for situations with

a fixed microphone position, such as on a pulpit where

the acoustical environment is more stable. The

adaptive filter is allowed to converge more slowly,

suppressing reverberation components even more

effectively. Depending on the acoustical environment

and the chosen mode of operation, up to 12dB of

additional gain is possible before acoustic feedback

occurs.

The Plena feedback suppressor also features a built-in

automatic mixer for the two microphone inputs. In

many situations, such as on a rostrum, a pulpit or a

conference table, two microphones are used to

capture the voice of a moving speaker better, even

though this increases the risk of acoustic feedback. To

counter this, the automatic mixer in the Plena

feedback suppressor reduces the gain of the

microphone with the lowest signal input and increases

the gain of the microphone with the highest signal

input. This way, it tracks the moving speaker for

optimum speech intelligibility, while maintaining a

maximum feedback margin by keeping the combined

gain constant. The automatic mixer function remains

operational even when the feedback suppressor is

deactivated.

Certifications and approvals

Safety acc. to EN 60065

Immunity acc. to EN 55103-2

Emission acc. to EN 55103-1

Region Certification

Europe CE Declaration of Conformity

1 2 3

Summary of Contents

Page 1 - Region Certification

Communications Systems | LBB 1968/00 Plena Feedback SuppressorLBB 1968/00 Plena Feedback Suppressor www.boschsecurity.com u Patented feedback suppr

Page 2

Installation/configuration notesLBB 1968/00 back viewParts includedQuantity Components1 LBB 1968/00 Plena Feedback Suppressor1 Power cord1 Set of 19“

Page 3 - Ordering information

Ordering informationLBB 1968/00 Plena Feedback Suppressora powerful DSP with a patented algorithm to suppressacoustic feedbackOrder number LBB1968/00

Bosch LBB 1968 User Manual

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Bosch LBB 1968 User Manual

Browse online or download User Manual for Security access control systems Bosch LBB 1968. LBB 1968/00 Plena Feedback Suppressor

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More documents for Security access control systems Bosch LBB 1968

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