I installed a master filter at a friends house yesterday (they have structured cabling) while the sync rate didn't change (appears to be ADSL1 max) the speed tests did. The downstream attenuation dropped by around 2dB (20 -> 18).
I'd expect better speeds than what is being delivered considering the sync rates etc but I do note they are getting all that Chorus SAT says they should:
Based on Chorus SAT:
This address is in an exchange area where the exchange has been upgraded with faster broadband equipment.
Exchange: Massey
Network upgrade scheduled:
- RBI Broadband > 1 Mbps by Jun-2013
I did the following tests using my setup of a Draytek 120 and a Asus RT-N16. I note it is only ADSL1 (G.DMT) but down the road a bit is cabinetised is this inflating the sync rate?
Before filter install:
Speedtest:

Sync rates:

After filter installed
Speedtest:

Sync rates:

So based on the sync rates shouldn't the download be closer to 5Mbit than 1?
