DSL Micro Filters

Filters are used to separate the ADSL signal on the telephone line from all devices besides the ADSL modem. If you do not install microfilters on all sockets which have devices plugged into them, this may result in ADSL performance problems, loss of service or interference on your telephone.

What is a microfilter / splitter and why do I need one?

There are two types of microfilters which may be used to filter your broadband enabled telephone line.
1) An Inline filter (supplied with all new OntheNet modems)
2) Splitter filter

Inline Filter
An inline filter is used to connect a single phone or fax through your ADSL enabled telephone line on an individual port or through a double adapter.
These filters must be connected to each socket which has any device connected to it, on the line the ADSL service is enabled for even if you will not connect the ADSL modem / router to that socket.

Ensure the ADSL modem is not running through a microfilter as this will *filter out* the ADSL signal to the modem.


Inline Filter

Filter Splitter
A Splitter is a small device that plugs into your normal telephone socket and splits the line into both a standard telephone socket and a ADSL broadband socket.  This removed the need to use a double adapter if you wish to use the phone and ADSL modem on the same socket.
A Splitter is basically a microfilter and double adapter in one.


Splitter Filter

Please note: Panasonic Cordless Phones may require a special Telequip filter as the regular filters dont seem to cut the well enough.  These are avaliable in both inline filters or splitter filters



If you have an alarm system that uses the telephone line or Foxtel digital, it is important not to forget this needs to be connected through a microfilter also.

Example Diagram

Below is a diagram showing a basic example of a phone and filter setup in a standard home: