Broadband Speeds are shockingly dreadful!
I'm slightly confused 
So, you have a filter in the NTE5 faceplate with the phone/modem connected and an extension cable running from the back of the faceplate? What is that feeding?
That suggests an extension cable from the back of the faceplate is causing (noise) problems and needs a filter, if there is something connected to it, or just disconnecting if not in use. Replacing the NTE5 faceplate with a filtered faceplate and, if it is in use, connecting the extension cable to the filtered connectors on the back (but not the bell wire) should reduce/cure internal problems - no additional filter should be needed. If you have anything on the extension that doesn't ring without the bell wire connected, just use a plug-in filter which will have a bell circuit inside.
After that, problems should be "not of your making"
Quote from: shiobi12 We have a cable that connects into the master socket that goes somewhere around the NES5 Split Faceplace and we plug the ASDL filter with the phone and broadband line into the NE5 Split faceplace.
So, you have a filter in the NTE5 faceplate with the phone/modem connected and an extension cable running from the back of the faceplate? What is that feeding?
Quote from: shiobi12 But because the internet is dreadful with the cable plugged into the Master socket, we plug it in the test socket of the master socket in order to get average speed although it still disconnects.
That suggests an extension cable from the back of the faceplate is causing (noise) problems and needs a filter, if there is something connected to it, or just disconnecting if not in use. Replacing the NTE5 faceplate with a filtered faceplate and, if it is in use, connecting the extension cable to the filtered connectors on the back (but not the bell wire) should reduce/cure internal problems - no additional filter should be needed. If you have anything on the extension that doesn't ring without the bell wire connected, just use a plug-in filter which will have a bell circuit inside.
After that, problems should be "not of your making"