Expert: Cleggsan - 5/30/2011

Question
My Tannoy subwoofer stopped working although the fuse is fine (the light comes on, but no sound).  I opened it, played with the connections.  When  I connect the center wire of a male RCA plug to the center wire in the speaker (I took apart the RCA plugs, so connecting directly to the wire in the speaker to the wire in the cable), the speaker vibrates.  However when I also connect the outer wire from the RCA plug to the outer wire in the subwoofer, no vibration is produced.  Could you pls explain why this is happening?  I assumed both pos and neg wires had to be connected.

Answer
Yes, you are correct - under normal conditions both wires must be connected to compete the circuit path for current to flow.  However, it seems, based on your explanation, the Tannoy has developed an internal short from speaker/amp connection to ground of the metal parts.  Do you have an ohmmeter/vom?  In the states we find in most hardware stores a small vom (volt-ohm-meter) for about $USD10$ (6 Pounds Sterling).  This can be used to check for shorted condition between either wire connection on the woofer to the metal basket, the amplifier, the jack  or other metal connections of the cabinet or other ground wires.

That is where I would start looking.  It is not an uncommon thing to happen.

But, let me know if we are on the wrong track and we will jump to another solution pathway.

Cheers.

PS: If you need further suggestion, please give me the model number of your sub.  Maybe the TS10?