What is an ADSL Filter?

An ADSL filter is a small device that is installed between your telephone and your wall socket. A filter is used to seperate the ADSL signal from your telephone line.

A filter is required for two reasons:

  1. The modem may create noise or static on the phone line.
  2. The ADSL connection may not connect, drop out or slow down.

All telephone devices on an ADSL enabled phone line will require a filter to be installed. This reduces the chance issues will occur with your home phone and internet services.

Note: Your ADSL modem does not need a filter to operate.



Where will I need to connect a filter?

An ADSL filter is required for all telephone devices that connect to your ADSL enabled phone line.

Below is a list of the most common telephone devices requiring a filter.

  • Corded/Cordless Telephones
  • Answering Machines
  • Fax Machines
  • Back to Base/Monitored Alarm System
  • Foxtel
  • Medi-alarm
  • Any other devices connected to your telephone wall sockets

How do I connect an ADSL Filter?

Connecting an ADSL filter is a quick process.

Most filters have 3 ports:


  • Wall Socket/Line
  • Phone
  • ADSL Modem

Step 1

Connect the phone line from the telephone wall socket to the 'Wall Socket/Line' port on your filter.

Note: Some filters have a cable fixed to the line port, in some cases this cable can not be removed.

Step 2

Connect your telephone handset to the 'Phone' port on your filter.

Step 3

Connect your ADSL modem to the 'ADSL Modem' port on your filter.

Filters should be connected up in the configuration below:

Repeat steps 1 and 2 above for each telephone device connected around your home.

Note: Telephone devices in different parts of the house will also require a filter/splitter to be installed. Try not to forget telephone devices in a garage, study or semi-attached unit.