VDSL/ADSL Filter Is an electronic device that isolates the ADSL and voice bands. ADSL in-line filter/splitter maximizes the performance of your ADSL (Asynchronous Digital Subscriber Line) service. It allows you to connect an ADSL modem and telephone device to the same ADSL port. It creates clearer voice communications and prevents interference by separating high frequency ADSL transmissions from phone signals. This filter is required whenever you connect a computer to the internet using Broadband over a standard telephone line.  This filters divide the signals on the telephone line between the high pitched computer modem sounds and the lower pitched human voices and hence clearer voice.