How to Tell if a Sub Is Blown Without Hooking It Up?

A subwoofer is a precious part of any car audio system. And believe me, you can’t introduce yourself as an audiophile without a deep bass in your sound system.

However, subwoofers can only provide improved sound quality only if they are in good shape. Let’s talk about yours! If you think your subwoofer is blown, you may be wrong.

I believe there can be some audio settings problem. However, you can only confirm that after testing your subwoofer correctly. I can quickly tell if a sub is blown without hooking it up by following methods. Let’s dive in!

Is It Possible to Test a Subwoofer Without Hooking It Up?

Yes! It’s possible to detect a blown subwoofer without connecting it to your audio system (power source). However, it’s not entirely possible.

But there are some signs that you should look for while doing a manual test. Therefore, you must be very careful and active to pick up that sign instantly. Otherwise, you may still be confused about whether the sub is okay or not.

5 Methods to Test a Sub Without Connecting It Up:

You can quickly judge if a sub is blown without hooking it up by following methods:

1. Visual Inspection:

The easiest method to know the answer is a visual inspection of the targeted subwoofer. While inspecting the subwoofer, check for any visible signs of damage, such as tears or punctures on the subwoofer cone, surrounds, and/or dust cap.

If these components appear to be damaged in any way, it’s like the speaker has been blown out at some point. Let’s say your subwoofer is mounted in an enclosure.

In such a case, you will have to remove the subwoofer from its enclosure to check it from every angle. Ensure you look over all components like voice coils, spiders, and magnets for signs of wear and tear or overheating.

You may also be able to see if there are any cracks on the magnet assembly due to dampening material breakdown, which would indicate a severe problem with your speaker system.

2. Gently Push the Subwoofer:

Now let’s say you have checked the subwoofer visually, and it appears to be fine internally and externally.

Another efficient method you can follow is to push your subwoofer gently and notice any rattling or distorted sound. Follow the below steps for a successful assessment:

• Slowly push the subwoofer: You must carefully and gently push it down so that you won’t get it damaged. Moreover, you should take your ear closer to the speaker to notice any uneven noise.
• Look for rubbing or scratching sounds: If your subwoofer produces an unpleasant sound after pushing it, it shows that your sub is blown. The noise can be due to the voice coil being misaligned or damaged.
• Uneven movement: If your subwoofer moves unevenly or shows a freezing movement, it could also mean you have a blown sub because the voice is stuck between the magnet.

Note: If your subwoofer is frozen, you quickly unfreeze it by replacing your voice coil. However, you may need expert help.

2. Check the Resistance:

Come on! Not hooking it up with any device doesn’t mean you can’t use a multimeter for a legit test. A multimeter allows you to measure the resistance of the subwoofer’s voice coil, which can help determine if there is a problem with the components inside the blown speaker.

To check this, first, set your multimeter to measure resistance so it reads ohms (Ω). Touch both leads from your meter to one end of the voice coil; generally, it will be labeled “positive” or “in” on one end and “negative” or “out” on another end.

The amount of ohms should match what is listed in manufacturer specifications for that specific model – if not, then you could be dealing with a partially blown subwoofer.

3. Use 9V Battery (Make a Home Tester):

Yup! You read it right. You can also test your subwoofer using a homemade tester (without an external amplifier to play audio playback). The main component of the tester is a 9V batter.

Please note that this method only checks for basic functionality and cannot detect all possible faults. Here’s how you can make a basic tester for a subwoofer using a 9V battery:

• To make the tester, you must get a 9V battery and a length of wire with alligator clips on both ends.
• Just connect one end of the wire to the positive terminal of the 9V battery and the other end to the positive terminal of the subwoofer.
• Now briefly connect the negative end of the wire to the negative terminal of the 9V battery and the other end to the subwoofer’s negative terminal.
• If your subwoofer rattles or the speaker cone moves unevenly, it means you have a blown subwoofer. But if everything looks good, your subwoofer functions correctly.

5. Smell Test:

If you suspect your subwoofer might be completely blown, you can quickly know about it after a smell test.

If you detect a burning or acrid smell coming from the subwoofer, this could indicate a sign that either the voice coil or other components have overheated and are damaged.

In most cases, if a driver has been over-driven beyond manufacturer specifications, then heat can build up in different parts of the speaker, which will cause them to melt and eventually fail.

The excessive heat generated can also lead to smoke, with an unpleasant odor emanating from your subwoofer’s cone.

What Does a Blown Subwoofer Sound Like?

When you have a blown sub, it can produce a variety of strange noises, such as buzzing, hissing, popping, or scratching noises. High notes may become distorted. Crackling may occur due to faulty wiring in a used subwoofer, while low notes will simply vanish altogether.

These distortions are usually caused by components within the speaker that have burned out due to excessive heat and decreased airflow, resulting in physical deformation of parts such as voice coils inside the driver unit itself. The subwoofer blows if you use too much power.

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