How to Tell If You’ve Blown Your Subwoofer

Blowing a subwoofer is more common than you might think, especially if it’s been pushed past its limits. Whether you’re a bass head or just someone who enjoys clean low-end sound, knowing how to diagnose a blown sub can save you time, money, and frustration.

In this article, we’ll walk you through the most common signs of a blown subwoofer and how to test it yourself.

Common Signs Your Subwoofer Might Be Blown

1. No Sound or Weak Output

One of the most obvious signs is silence. If your subwoofer suddenly stops playing, or it sounds extremely weak and distorted, something’s not right. Make sure it’s getting signal and power before assuming it’s blown.

2. Distortion at All Volumes

If your sub is crackling, popping, or distorting even at low volume levels, there’s a good chance the voice coil or cone is damaged.

3. A Burnt Smell

A blown voice coil often leaves a telltale sign: a strong burnt smell. It may smell like burning plastic or electronics. If you notice this after your sub has been cranked up, the coil may have overheated and burnt out.

4. Stiff or Unnatural Cone Movement

Gently press on the sub’s cone with your fingers. It should move smoothly and evenly. If it feels scratchy, stuck, or uneven, the voice coil might be misaligned or damaged.

How to Test Your Subwoofer

You don’t need fancy tools to test your sub. Here are a few simple methods:

1. Visual Inspection

Remove the sub from the enclosure and inspect:

• The cone for tears or cracks
• The surround for separation
• The terminals and wires for damage or burns

If you see burnt marks or broken components, that’s a red flag.

2. Multimeter Test

A digital multimeter is your best friend when diagnosing subs.

• Set it to ohms (Ω).
• Touch the probes to the sub’s terminals.

Results:

• A reading between 1 to 8 ohms (depending on your sub’s rating) is normal. Check what your sub is supposed to be reading on the sticker normally on the back of the subwoofer.
• A reading of 0 ohms or OL (open loop) means the voice coil is likely blown.

3. The Battery “Pop” Test

This is a quick trick to test your sub without equipment.

• Grab a AA battery.
• Briefly tap the battery’s positive and negative ends to the sub’s speaker terminals.

What to expect:

• A healthy sub will make a soft “pop” sound, and the cone will move slightly.
• If there’s no pop or movement, the sub may be damaged.

Warning: Only do this briefly. Holding the battery too long can damage the sub further.

Tips to Prevent Blowing Your Sub

• Avoid excessive bass boost or gain on your amplifier.
• Make sure your sub is in the right enclosure for its specs.
• Use a clean, undistorted signal—clipping is a speaker killer.
• Don’t underpower your sub—too little clean power can be just as bad as too much.

Still Not Sure?

If you’ve done these tests and still aren’t sure what’s going on, it might be time to visit a car audio pro. If you are located in the Tallahassee area Boom for Your Buck Mobile Audio Installations, can help you diagnose, repair, or replace your subwoofer and make sure everything is dialed in for long-term performance.