Solder fault symptoms

I spent some time recently adjusting speaker positioning and experimenting with primary connection to HF vs LF etc. Speaker cable is NACA5, dealer soldered into an F configuration. Cable and solder is probably a good 10 - 12 years old and has been moved around a fair amount during that time.

As a result of my experimentation I appear to have have killed the music ! Trouble shooting points to a problem with one cable rather than the amp or speakers (fortunately). One is fine, smooth and musical and the other is hard and shouty. I have removed heat shrink and there is nothing obvious. Is this typical of cracked/dry solder or could it be something else such as broken strands ? I don’t want to have it re-soldered only to find the same problem…

A dry soldered joint looks completely different from a properly made one, sort of grey and crystalline with the solder obviously not flowed properly and solder is most unlikely to crack because tin/lead is quite flexible. If the NAC A5 had been inadequately tinned, then you could I suppose have a joint that looks ok from the outside but where there is lack of contact with the cable inside. I would expect to be able to feel some slight movement between the cable and the plug in that case. There should be no movement at all of course.

As to broken strands, one or two wouldn’t make such a difference and if it were a lot then again I would expect to be able to tell that the cable felt more flexible there.

You haven’t explained how you determined that it was a cable rather than a loudspeaker or equipment. But if it were me, I would run those tests again. I know myself how difficult this sort of fault-finding can be.


if you have found the problem to be a speaker cable - cut off the speaker cable ends and get them professionally re soldered surely is the way to go.

Tests were just listening tests. Swapped cables at the speaker and the poor sound moved to the other speaker, eliminating a speaker issue. Then swapped cables at the amp and the poor sound stayed with the same speaker, eliminating a faulty channel in the amp. Poor sound could be moved to each speaker and from each channel but always on the same cable.

What does a poor connection sound like typically? Not poor enough to completely break the connection obviously, just enough to reduce the integrity somehow. Does hard/shouty/brittle higher frequencies make any sense ?

That is what I plan to do, I was just wondering if the sound is typical of symptoms of a bad/weak connection…

I’m not sure I have ever heard it knowingly, but I would expect there to be distortion which could come across as hard or brittle. Since it’s pretty well certainly the cable from the tests you have done, getting the cable resoldered would be a good plan as Mick says, preferably with new plugs too I suggest.


This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.