I posted this in the XDSL group, but that group is too quiet.
Recently, I had a new phone service installed, shared with ADSL. I used the filters shipped with the DSL device, but I'm getting lousy sound on my old cordless phone, Sony SPP 2000, a 1.7 Mhz instrument. Yes, I know that such phones were always inadequate and readily overheard, but the handset is cool looking, it has swappable sealed lead acid batteries which means the handset is never recharged in the base. It's survived being dropped quite a lot.
Anyway, do these require a different filter than the one that came in the box?