tolien said:It's not guaranteed that the SNR margin will change - if you've got decent extensions it doesn't matter. It is, however, worth trying, and seeing if there's a change.
If there is, yep, go through installing a new filtered master faceplate. Only possible with NTE5 though, older sockets need a visit from your friendly BT engineer.
Isnt it actually illegal to tamper with the master socket itself? As its BT property?
Thats one of the reasons I had BT install mine (already had a NTE5).