What a load of rubbish. If you do not know FACTS don't try spreading false information.

1. Sockets without phones or telephony devices (modems, faxes &c) DO NOT need filters.

2. Wire 3 may be needed. Some phones that are still manufactured and available need a bell circuit and will not function if wire 3 (as you call it) is not connected.

Edited by MHC (Mon 09-May-11 09:21:39)

Many people need their broadband service carried to a different room in the house from the one containing the telephone master socket. Unless you are using wireless equipment this is done using a telephone extension of some type. It is vital that a microfilter is placed on all extension points on which telephone devices are attached

This is cut & paste from & current Plusnet doc, same advice can be found in BT settup docs.
I my case filtering empty sockets stopped dropouts & improved speed approx 20%
But every house setup is different so try with & without
Yes you are right some old stye phones will still need wire 3 ( ring wire )
Ps I have now removed all extension sockets & use DEC phones / powerline plugs
Best wishs Mike

This page I guess http://www.plus.net/support/broadband/help_and_setup...

It's out of date as it doesn't allow for the modern filtered faceplate.

The issue raised by the OP is specifically concerned with extensions coming from the already filtered connectors on the back of a filtered faceplate on the Master socket.

It is probably best not to cloud the issue ( especially for any newbies reading) with the more general case of unfiltered extensions.

In reply to a post by Copperking:

I my case filtering empty sockets stopped dropouts & improved speed approx 20%

Out of interest can you say what a filter plugged into an empty socket is filtering?