Drm is a technology aims to improve sound quality of am transmission below 30 mhz and to reduce interference common in medium wave environment . new compression technologies known as mpeg4 advanced audio coding ( aac ) and spectral band replication ( sbr ) are employed to offer sound quality comparable to that of fm transmission 它是针对30mhz以下的调幅（ am ）广播而设计，大大提高了音质，并改善了中波广播较易受干扰的情况；系统采用最新的压缩技术mpeg4advancedaudiocoding （ aac ）和spectralbandreplication （ sbr ） ，音质足可与fm广播媲美。
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Drm is a technology aims to improve sound quality of am transmission below 30 mhz and to reduce interference common in medium wave environment . new compression technologies known as mpeg4 advanced audio coding and spectral band replication are employed to offer sound quality comparable to that of fm transmission 它是针对30mhz以下的调幅am广播而设计，大大提高了音质，并改善了中波广播较易受干扰的情况系统采用最新的压缩技术mpeg4 advanced audio coding aac和spectral band replication sbr ，音质足可与fm广播媲美。
