A distributed filter, or micro-filter, is a small electronic component that fits between your phone line and a regular voice device, such as a phone, a fax, or any device with a regular modem such as a cable box, alarm system or digital TV. When DSL (ADSL) is provided over voice lines, all devices in the house except the DSL modem must be connected through filters. The filter protects the devices from high frequency noise. They are low-pass filters.
The filters supplied with your DSL kit are used to channel the DSL signal directly towards the DSL modem. Without the filters in place, your DSL signal would travel and interact with every telephone device in your house before getting to the DSL modem. This would result in either a loss of synchronization with the DSL signal or very poor performance. Make sure you have all phone lines with devices attached filtered, EXCEPT for the line connected to the DSL modem from the wall jack.
You can plug your modem into micro-filters (ADSL side because otherwise you won't get sync), not in-line filters. On a wall mount filter, the DSL goes in "Line" if it has two. Examples of the two:
|Wall mount filter|
If you need to purchase micro-filters, I recommend Excelsus Technologies
A splitter at your NID recommended if you have 4+ phones in your house.
Feedback received on this FAQ entry:
- I just found out that I've been installing the in line filters backwards for years! Does this really matter or is a passive device that works either way despite the markings on the filter? In NYC, it's rare to find the place where the cable comes from the wall because it's always behind furniture that cant be moved from some reason. I've been connecting them inline at the phone. Same thing with wall phones, hard enough to squeeze the filter in there without having to have reversing cables in there. I've never heard anybody complain about noise on phone or bad dsl service, so I wonder if it really matters or not.
2011-10-25 21:30:38 (mikemercury )
- If you don't use filters on your phone devices, you may experience static when you use your phone. You may also experience some degradation on your DSL service. Slows speeds and loss of synch on the DSL modem are common examples of this.
2008-11-27 18:34:55 (Meteor Dive )
- This comment:
"The filters supplied with your DSL kit are used to channel the DSL signal directly towards the DSL modem. Without the filters in place, your DSL signal would travel and interact with every telephone device in your house before getting to the DSL modem"
Can you provide a little more explanation? Particularly, can you answer what effect an unfiltered phone might have on the DSL signal?
by speedaemon91 edited by redxii
last modified: 2003-03-27 08:43:45