Just wanna clarify once & for all... Do you need to use a line filter on the jack where the modem connects to?Or just on the jacks where phones connect? Does it make any difference at all and if so how?Because currently we seem to be able to function with a filter only on the phones
No you dont. If you are using micro line filters (ie not a central filter) then you only need filters on each and every POTs (Plain Old Telephone) device such as a phone/fax/analogmodem/skybox, the ADSL modem itself does not need a filter and infact must connect directly to the phone line.
micro filters as you normally get with the modem and from high street stores with a BT plug input and a phone output socket and ADSL output socket actually just have a filter component on the phone output, the ADSL socket is just connected to the input plug.
For optimum operation I always recommend a centrally installed, this means you no longer need any other filters on pots devices, and you totally side step all manner of issues created by the house wiring that micro line filters cannot fix.
Yup i'd agree with Cyril7 as of right now im using a sinlge port filter for my phone and no filter at all for my adsl modem so no you dont need a filter on the jack point you have you modem plugged into unless you also have a phone connected to the same jack but you will need filters on any other jack that has a phone plugged into it