FAQs

ADSL Filters

Details

Parent Category: Broadband

Written by Administrator

It’s a common question. What are they, where do I put them, how many do I need?

What are they?

When you have ADSL enabled on your phone line, you are now running voice and data along the same piece of copper wire. The voice and data operate at different frequencies. But without filters you can hear the data noise when you use the phone. So the filter will literally “filter out” that data noise when you are on the phone.

Where do I put them/how many?

You need to put a filter into a phone socket wherever you intend to plug in some equipment. So every socket where you are going to use a phone, you will need a filter.

You will also need a filter where you plug in your ADSL modem or router, whether you are connecting a phone at the same place either.

Also don’t forget other devices like Sky which use analogue modems they will need a filter as well, and any answer phones etc.

Too many filters

Don’t get caught out by this one. A common mistake is to put too many filters in a chain. This normally happens when people are using phone socket extensions to extend the reach of their telephone
line as they don’t have a socket close enough.

This is a normal set-up where distance is not a problem:-

Telephone Wall Socket - ADSL Filter - ADSL Modem/Router

But your modem might be located further away from your phone socket and the supplied RJ11 lead might not be long enough. So just use a standard telephone extension cable available from Argos, Currys, etc etc.

Firstly this is the wrong way to do it.:-

Telephone Wall Socket - ADSL Filter - BT Telephone extension cable/reel - ADSL Filter - ADSL Modem/Router - PC/Xbox

That just won’t work because you have two filters in the loop. This is the way to do it:-

Telephone Wall Socket - BT Telephone extension cable/reel - ADSL Filter - ADSL Modem/Router - PC/Xbox

You only need to filter once, so try to do it as close to your modem/router as possible.