Designed for volume and tone adjustment in audio devices, the BD37033FV, BD37034FV and BD37068FV for car audio systems and the BD34701KS2 for AV receivers signal an expansion of ROHM's BD37xxx and BD34xxx series of sound processors. Included in these products is a RF noise removal function, which ROHM claims is an industry first. The RF removal function has been developed using proprietary analog technologies, designed to minimize noise introduced in electrical equipment when receiving phone calls – by more than 10x.
The RF noise removal function cuts unpleasant noise introduced in audio equipment when receiving wireless phone calls – without the need for additional components or external counter-measures. Sound leakage is prevented when power supplies, which are attached to an external power amp (BD37034FV), are turned OFF to only 1/30th. Additional features include technology used to eliminate noise in the low-frequency region that cannot be reproduced through simulation, and a switching operationwhich minimises popping noises generated when adjusting the volume and/or tone for smooth, natural audio transition.
Digital and analog are the usual two methods for performing volume and tone adjustment in sound processors. With digital systems, however, there is concern over essential sound quality degradation caused by bit drops during volume attenuation, making analog the preferred method. ROHM has used its analog expertise to lead the industry in high fidelity sound processor development. With the increased demand for higher sound quality in audio devices and systems, alongside the widespread usage of mobile phones, it is much more important to minimize RF noise when receiving incoming calls. The devices fulfill this demand with features like the RF noise removal function for audio equipment that cuts noise generated by incoming phone calls, along with the audio leakage prevention function.