Speaker System Rf Modulator AH40-00175A Genuine OEM. This is a Genuine OEM part. This RF modulator (part number AH40-00175A) is for speaker systems. RF modulator AH40-00175A sends and receives audio signals to the receiver. Because the speaker system contains capacitors that can retain a lethal electr... - Speaker System Rf Modulator AH40-00175A Genuine OEM.