Identifying and Fixing PA Speaker Problems – Expert Advice
You might be giving a speech and suddenly, your loudspeaker fails. Maybe you’re just setting up a PA system and the speakers disappoints. There’re many reasons why a loudspeaker may fail. Before looking at these problems, it’ll help to understand how these speakers work.
Basically, these speakers work by amplifying sound from the connected component device. Most of these speakers have a woofer, mid-range drivers and a tweeter. They vary in size, power, and design.
However, they work the same way. As sound moves into the speaker through a cable, the sound is directed to the appropriate driver. The input frequency is converted into mechanical movement. Consequently, the cone moves accordingly, pushing the air around it to produce sound.
With that said, here’re some tips on identifying and fixing PA speaker problems.
What May Go Wrong With A Public Address Speaker?
Public address speakers often fail as a result of improper use. Some of the most common issues with these speakers include:
- A damaged enclosure that exposes internal components to damage
- A blown electrical fuse
- A blown thermal fuse
- Faulty voice coil
- Faulty crossover network
- Damaged solder connections
- Faulty cables
- Improper cable connections
- Damaged driver cone
- The speaker might not be in phase
- Broken level controls
Although some of these problems may be shocking, they’re all repairable. Read on to know how.
How to Identify PA Speaker Problems
Tip 1– In case the loudspeaker is not producing any sound, check whether the source component is properly connected and is adjusted properly. If the components are well connected, you’ll need to disassemble the cover. First, power it off from the mains power before any disassembling. Check the fuse for any signs of damage. In case the fuse is blown, replace it.
Tip 2– If there’s no sound from the drivers, try testing the fuse, drivers, and crossover wiring. Replace any damaged part. If possible, you can test the components on another similar speaker. If you still fail to get sound, the receiver may be faulty.
Tip 3– In case one driver is not producing any sound, you’ll need to test it. You can press the cone lightly with your finger to check for any vibration. In case it’s not vibrating, then you should replace the driver.
Tip 4– If you’re getting distorted sound, try flexing the sound cable at low volume. If the sound changes while flexing the cable, clean the connectors and replace the cable. Also, check whether you’ve connected the cable properly. If no sound, press the cone with your fingers repeatedly. In case it’s not moving smoothly, replace the cone.
Tip 5– If the loudspeaker sounds noisy, the voice coil may be damaged. You’ll need to check it for any signs of damage such as holes. In case you find a hole, seal it with rubber cement. If the damage is major, replace the driver. If the cone has no signs of damage, try cleaning the volume control using an appropriate electronic contact cleaning agent.
Tip 6– In case you’re getting intermittent sound, check whether all connections are fixed properly. Also, check the coil and test the fuse.
Tools Needed For Fixing PA Speaker Problems
You’ll need these materials and tools to repair your loudspeaker:
- Replacement component
- Speaker repair kit
- Rubber cement
How to Repair the PA Speaker
Step 1- Turn off the mains power and unplug the power cable. If it’s not powered by AC, unplug any speaker cable.
Step 2– Next, start disassembling the speaker. Remove the grille to expose the drivers and crossover. Depending on the make of your loudspeaker, the grille may be secured with screws, snaps or glue.
Step 3– Detach the drivers. Some drivers are screwed while others are sealed. In case it’s sealed, use a sharp knife or blade to detach it. When reattaching the driver after repair, use an appropriate sealant in case it was sealed in place.
Step 4– Lift the speaker driver to expose wire connectors. Remove the connectors carefully with a pliers. Some connector wires may be soldered in place.
Step 5– Remove the crossover if necessary. Most crossovers can be accessed easily from the front while others can only be accessed after removing the main driver.
Step 6– Test the fuse using a multimeter.
Step 7– Using the multimeter, test the resistance on the crossover network, terminal block and the driver. The resistance of most drivers is written on the back in ohms.
Step 7– Replace any damaged component and reassemble the unit.
Repairing a Damaged Cone
In case you found a small hole or tear on the cone, you’ll need to seal it. Apply some rubber cement on either side of the hole. In case the tear is extremely large, the cone may need replacement.
How to Obtain the Correct Polarities (Speaker Phasing)
In case you have wrongly attached the speaker cable, you’ll get poor sound or no sound at all. Thus, you need to ensure that the speaker is in phase. This means that the terminals should be properly connected. The positive terminal is usually red in color whereas the negative terminal is black.
However, if your cable is not colored, ensure the positive terminal of the source is connected to the positive terminal on the loudspeaker. The negative connector should go to the negative terminal. This way, you’ll get rich sound.
While identifying and fixing PA speaker problems, you might wonder whether to repair or replace some components. It’s often inexpensive to replace the fuse, cables and sealing tiny holes on the cone.
However, replacing the driver might be a bit more expensive depending on the brand. If it’s beyond your budget, you can have the driver re-coned. If an issue is beyond repair or replacement, consider buying a new PA speaker.