System Problems

[Serial_Apologist]

When I first joined the Beeb I was sent to the old Camden Theatre as a back room operator on a live broadcast of Friday Night is Music Night, relieving an experienced operator in a change of shift. As he left, he pointed to one of the steel grey equipment bays, and said-- "If you go off air, kick it just there" I spent the whole evening staring at the spot petrified!

When I was a small boy, we had a black-and-white PYE TV set which would crash from time to time. Whatever the problem was was solved by giving the set a bash on the top. After a few such occasions, we found that all that was needed to get it back on again was to take a step or two towards the set, and it would automatically come back on. Then it would go off the moment we resumed out seats! My mother always insisted that the set knew a slap was coming, and was deliberately playing games with us!

[Conchis]

Sorry to continue with this very boring saga, but the advice I've been getting from you all has been very helpful thus far...

I've been in touch with Cambridge Audio, who have advised me that Mordant Short speakers are no longer being made. They put me in touch with an associate company based in Norwich, who have advised me that the speakers probably need replacing. I think this is nonsense and have said as much - all I asked was what type of adhesive to use on the rubber around the woofer.

[Dave2002]

Try phoning the Wembley LS company I mentioned earlier. It may not cost much to make the call, and at least they could hopefully give you some sensible advice.

[Gordon]

Try phoning the Wembley LS company I mentioned earlier. It may not cost much to make the call, and at least they could hopefully give you some sensible advice.

I'd endorse that advice re the Wembley people. My friend had some speakers that developed a similar fault and these people refurbished the cones and their mounts. His had perished badly!! The roll surrounds on some cones are of a type of rubber/soft plastic that does deteriorate with age - solvents leeching away, de-polymerisation - and the decay causes the cones to droop and thus cause the voice coils to rub against the magnets. The clearances there are very small in order to get the strong magnetic field required and so it takes very little to get the grating sound to occur. Another cause of sound deterioration is physical distortion of the voice coil assembly due to overheating ie playing too loud for too long!!

As an amusing aside our kids had a space hopper which our hamster, who was given free run in the garage in the winter, ate the ears off!!! Keep your hamsters away from your speakers!!

[MrGongGong]

I have another thought, which I slightly hesitate to suggest... I once had a fault with an amplifier. I took the amplifier for a little drive of a few miles. When home again it worked fine. It's an easy thing to try...

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If you are a virgin and it's a full moon then this is bound to work every time