I've had a look through all the forums and could not find an answer to my question, so am hoping somebody can help

I have extremely high line attenuation 63.5db

Is there anyway to reduce the attenuation noise as i'm sure this is what is slowing down the sync speed. Or speed up the Sync to nearer the 3.5MB?

Netgear WG834PN
UKONLINE 8mb (capped at 3.5mb to give stabilty)
Modem plugged directly into the BT test port
New ADSL Nation microfilters (but have tried the modem with no phones connected)
Down Sync 2100kbps aprox
Up Sync 768kbps aprox
BT phone line to Reading South Exchange
Haven't got the noise margins at the moment

Looking forward to somebody being able to help