Repair by replacing speaker in system
Many loudspeaker systems have two or may be three individual speaker drive units in them, each one typically covering a different frequency range. In general the smaller the drive unit, the higher the frequency range it covers.
Replacing a drive unit in a loudspeaker system is relatively straightforward and can be undertaken with only a few tools and a few precautions.
The first stage is to identify the loudspeaker that is causing the problem. It may be that one loudspeaker does not work, or alternatively one may sound distorted. Listen carefully to each speaker in the loudspeaker system with music playing as this is the easiest way to detect distortion.
Once the individual unit that is faulty has been located the next stage is to gain access to the speaker system to remove it.
In larger systems there is a front board for the protective speaker cloth. This can normally be removed by simply easing it off to reveal the loudspeaker drive units.
In some loudspeaker systems, access fort he repair or replacement needs to be gained via the back - unscrew the back and open the enclosure out - it may be necessary to move or remove some sound absorbent material to see the speaker.
Once access has been gained to the speaker, it can be unscrewed and removed. It will be attached via two wires. These may be pull off connections or they may be soldered. Remember or note the polarity of the connection. Typically one wire is red and the other black and there are similar marks on the speaker. This is to ensure the correct phasing.
Once removed the new unit can be selected. Fortunately hole sizes and screw fixing positions seem to be fairly standard across a wide number of units, so you may be able to select a replacement unit with the same fixing positions. Performance is also important - select a unit with a very similar performance and then the balance of the system can be maintained.
Consider also replacing any capacitors in the cross-over network. They may be old and their performance reduced. Also consider replacing the sealing foam used to seal the cabinet around the speakers. The enclosure needs to be airtight.
When the replacement unit and possibly cross over capacitors and foam have arrived, these can all be fitted into place, ensuring he phasing of the speaker is correct.
Assembly is the reverse of the disassembly, so it should be fairly straightforward. Once assembled it can be tested and the newly repaired loudspeaker can be enjoyed as it has been returned to its former glory.