Desk Top “Noise Away “ Amplified DSP noise cancelling Speaker User Manual bhi Ltd DSP noise cancellation products for radio and voice communications 1067-105D iss B
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bhi Desk Top “Noise Away” amplified DSP noise cancelling speaker 2. Introduction The bhi Desk Top “Noise Away” amplified DSP noise cancelling speaker greatly improves the clarity and intelligibility of speech in radio and voice communication systems. It is suitable for use in base station applications where background noise and interference mean that you cannot clearly hear what is being said. The speaker will enable the user to listen and concentrate “stress-free”.
. Installation The speaker is supplied with a mounting bracket that can be left on in case of permanent fixing, or removed altogether depending on personal choice. Connect the 3.5mm mono lead supplied to the extension speaker socket of your equipment and the 4mm black and red plugs into the corresponding red and black sockets on the rear of the speaker. Connect the fused DC power lead supplied to a power supply capable of providing 12 18VDC @ 300mA. (The centre pin of the 2.
7. Setup mode To change the number of DSP levels or listen to the demonstration modes, it is necessary to put the module into the setup mode. To do this, ensure the module is switched off. Press and hold the DSP level button. Turn on the module and a 2 tone beep will be heard indicating that the module is in the set up mode. Releasing the button after the first 2 tone beep will enter demonstration mode 1. Releasing after the second 2 tone beep will enter demonstration mode 2.
9. Demonstration modes. Demonstration mode 1 The module switches the noise cancellation on for 1.5 seconds, then off for 1.5 seconds. It will then move to the next level and repeat the process. This mode is particularly effective at demonstrating the different DSP levels. A lternatively pass a clean audio signal through the module to see hear how little the DSP alters the speech. Demonstration mode 2 The module switches the noise cancellation on for 3 seconds then off for 3 seconds.
10. Specifications DC Power DC input voltage Current consumption 12 to 18 Volts DC 300mA Audio Input Impedance Minimum input level Maximum i/p audio Terminated with approximately 8 Ohm load 50 mV – 500mV 5 Watt Audio output Output load Audio bandwidth Controls Indications Connections 2.5W 8ohm 50 – 4.3KHz Power bypass/Function button Power ON/ FUNCTION 2.1mm DC power jack (Centre +ve) 3.
types of output sockets is not enough for the speaker electronics to process the signal effectively. bhi have another product that will work with these levels of signal, the NEIM1031MKII (DSP Noise Eliminating In-line Module). Please contact bhi for more information. See end of operating manual for contact information. Sometimes there is a short delay before the noise cancellation is active: • This is due to the time the DSP takes to start processing the signals.
bhi Desk Top “Noise Away” Speaker Dis-Assembly and Audio Adjustment Procedure The Speaker is set up to operate with a wide audio input level range. But under certain conditions, like using the speaker with a shortwave receiver, you may need to adjust the audio settings of the amplified DSP module to obtain optimum performance. Note: This procedure should only be carried out by people with the relevant skills. 1.
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