Speaker Trouble?

How do I know if my speaker needs to be repaired or replaced?

Sometimes the answer to this question is quite obvious just by examining it. Is the paper torn? Is the cone damaged? Is it bent out of shape?
These are sure indicators that the speaker needs replacement or repair.

If this is not the case, try this simple test:

If there's no sound at all and you want to see whether it's the amp or the speaker's fault, open your hand and apply a little pressure on it (but not on the cone) to make it move in and out. If it makes a scratching sound, it has been submitted to exess heat.

If too much power has been sent to the speaker in one great surge, or if it has been in operation for a long period of time at high volume, the coil will overheat causing it to deform and/or burn out. The reason you are hearing this scratching is because the coil is rubbing against the magnet. This should not happen and you'll know for sure that the speaker is at fault.

Another speaker test:

Step 1 (optional)
If you have an ohmmeter, switch it to its finest setting and check the resistance of the coil. Depending on the speaker this measurement can vary, but anything under about 10 ohms (but not exactly zero) means the coil is OK. Hopefully you'll notice that the speaker makes a ticking sound when you touch both terminals. This means that it works. If there's no ticking or the ohmmeter reads exactly zero (i.e. short circuit) or infinite resistance (i.e. open circuit) you can try step two, but chances are, it's blown and you'll need a new one.

Step 2
Take a 6 or 9 volt battery and connect it directly to the speaker (positive and negative does not matter here), as you do so, the speaker should make a ticking sound. If it doesn't make any sound it's not working.

One last check:
Although this is not so common, check to see if the wires on the underside of the speaker terminals are making contact or have been disconnected or broken off for any reason (while handling a screwdriver or another tool or object that fell into the back of the speaker itself, for example). This can sometimes happen with combo amplifiers because the back of the speaker is not protected from things falling inside it. If this is the case, just solder it back into place and away you go!

By the way, I would really like to know if any of this info is helping you guys get some insight into the wonderful world of DIY repairs! If you have any comments or suggestions, please make a post here or email me at rubencardos2@hotmail.com.