BHI In-line module - 5W Amplified DSP Noise Canceling Inline Module

The bhi DSP Noise Canceling In-Line Module cleans up noisy signals and works on most radios and receivers. It features the latest bhi DSP noise canceling technology which offers better audio quality to the listener when operating in noisy conditions on all radio bands. As a result, the audio is clearer and more intelligible.

Easy to connect in line with your radio

The In-Line module has a 5W audio amplifier and connects between the radio and the speaker. Speaker audio is muted when headphones are connected, and when the unit is turned off the audio bypass function routes the signal directly to the speaker.

Simple control of all features

The In-Line module is powered by a suitable 10 to 16V DC power supply and has a three-position switch that turns the unit on and turns noise cancellation on and off. The "Status" LED lights red when power is applied and turns green when noise cancellation is active. The unit has an audio input overload LED, an audio output level adjustment control and is supplied with a 3.5mm mono cable, a DC power cable with fuse, a user manual and 4 small pins Rubber.

Characteristics

• 8 levels of noise cancellation from 8 to 40 dB
• Tone reduction up to 65 dB
• Customized 5W audio amplifier
• Audio bypass function when turned off
• Speaker output connection 3.5 mm mono jack socket
• Headphone socket 3.5mm mono jack socket
• Audio input overload indicator
• DC power supply 10 to 16 VDC (500 mA min)
• Compact unit, 135mm x 65mm x 46mm, weight 0.3kg

What's inside the unit

The In-Line module uses a powerful programmable DSP audio processing chip that takes advantage of bhi's DSP noise cancellation technology. This high-performance chip delivers exceptional sound quality and incorporates a complete audio signal chain with 16-bit A/D converters and digital interfaces to accept the signal through the fully flexible digital processing architecture at analog line level.

The audio amplification stage is provided by a Texas Instruments TPA3111D1PWPP 10W Filter-Free Mono Class D audio power amplifier chip with 94% efficiency, which eliminates the need for heat sinks and saves PCB space.

Main features of the audio DSP chip

• A complete DSP-based mixed audio system, consisting of a fully programmable 16-bit Dual-Harvard DSP core, a patented high-resolution block floating-point WOLA filter bank coprocessor, and an input/output processor ( IOP) along with several peripherals and interfaces that optimize the architecture for audio processing.
• Built-in converters and powered output
• Extremely low power consumption: less than 5 mA at 20 MHz to support advanced operations; supply voltage 1.8 V
• “Intelligent” power management: including low-current standby mode that requires only 0.05 mA
• Excellent fidelity: 88 dB system dynamic range, exceptionally low system noise and low group delay.

DSP Noise Cancellation:

The DSP noise cancellation in all our products uses techniques that study signals in both the time and frequency domains simultaneously. The algorithm searches for signals with speech and noise characteristics. Signals with modulated speech characteristics pass through, and other sounds with modulation frequencies higher or lower than speech are removed depending on the selected filter level (8 to 40 dB). There is virtually no distortion of the speech signal, even for extremely low signal-to-noise ratios of 0 dB and below, and the technology automatically adapts to changing noise environments, so no noise filter training is required. If the signal-to-noise ratio is extremely low and/or a high level of noise suppression is selected, the system may produce artifacts in the form of slightly robotic speech. Customers can adjust the noise suppression level according to their needs.