Would it be best to:
Use the filter used for voice to run to:
a) a phone port on a laptop for it's fax modem
b) a stand alone facsimile unit or all-in-one
run a 'raw' line to these units and let their own filtering circuitry handle the out of band signals
is the answer dependent on the brand of fax machine / modem card?
It seems a little obvious that the filter would be preferred as the faxing does use the voice bandwidth.
QUESTION ANSWERED - USE A FILTER FOR YOUR FAXING