Showing results for 
Search instead for 
Did you mean: 

ADSL crosstalk noise.


ADSL crosstalk noise.

Since ADSL was added to our BT line, the audio quality has suffered very badly. Whether we use the PlusNet supplied USB modem or our 3-com router, when locked to the ADSL carrier, the level on the audio section of the line drops 3 or 4dB, and significantly increased noise and mush makes phone calls tiring and unpleasant.

All the obvious potential causes have been checked and eliminated - for instance, with just one phone connected and using the PlusNet-supplied combination of modem and filter, the audio is degraded as soon as it locks to the carrier,. The installer who recommended PlusNet to us also supplied the router and the extra splitter/filters, and he tells us that this problem is not uncommon, and that in other similar cases, he has never been able to get a significant improvement in audio quality despite hassling BT and demanding a level check etc.

Can you help?

ADSL crosstalk noise.

Hi there,

Welcome to the forums.

Noise on your line can be caused by dodgy wiring, poor quality or defective filter(s) or some types of DECT phones. Remember to ensure that any Sky boxs are also filtered.

If you are confident that everything is fine with your equipment I would raise a voice fault with BT. Do not mention adsl when talking to BT retail if possible and simply get them to check the voice side of things.

If that does not resolve the issue, then raise a ticket to support and get them to have the adsl side checked.

Ensure that you have checked and double checked everything at your end before raising an adsl fault. If it is found to be your internal wiring or equipment at fault, BT may levy a charge.

See the tutorial here for further info and advice.

Let us know how you get on.
Community Veteran
Posts: 6,983
Thanks: 8
Registered: 10-04-2007

ADSL crosstalk noise.

It may also be well worth trying some better quality filters to see if this reduces the noise. Excelsus Z-420UK-P2J Microfilter would fit the bill and are available on line from many places an example is here

Try removing any extension cabling

Do you have any extension telephone sockets wired into the master socket?

I had a similar problem. Telephone callers could hardly hear us, and we could hardly hear them. Two different microfilters made no difference to our problem.

It turned out to be the old aluminium wiring used for telephone extensions from the master socket.. Once I unscrewed the front of the master socket and plugged the filter (and telephone and modem) directly into that socket the problem was gone. So very shortly afterwards was the old extension cabling...and the extra 10 db attenuation on the ADSL line it was causing. I guess it's copper or nothing in the brave new ADSL world.

ADSL crosstalk noise.

Been away for a week and just returned to find ske1fr v. helpful suggestion. Will investigate at earliest opportunity, and many thanks for the tip.