The car amp turns on but no sound from subs.
This is one of the many problems you may face in your journey of becoming a car audio enthusiast.
Car stereo systems are complex because they involve more than just one component. And oftentimes, failure of one of those component affects the performance of the others.
A car amplifier provides an amplified signal to your subwoofer. The speaker then converts this signal into the sound we hear. But if there’s some problem with the amp, you may not hear anything at all.
This issue is different from a blown speaker where you get a low (albeit distorted) sound.
Some people think that no sound from subs is due to the faulty or blown amp, but it’s not entirely true and can be caused by various other reasons ranging from bad RCA cables to amp’s gain mismatch, too.
My Amp has Power But No Sound From Sub or Speakers
Before anything else, check amplifier’s RCA pre-outs and speaker input connections. These connections are solid and tight, then check subwoofer output and make sure it is not 0. Then check power and ground connections for the amp. Lastly, make sure the amp volume and gain knobs are properly adjusted.
In this article, we’ll find different solutions to this issue.
1. Check Amp’s Input and Output Signals
First of all, check cables that connect amp to the head unit.
You need to make sure that the amp receives an input signal from the head unit via speaker level inputs (high-level inputs) or RCA level inputs (low-level inputs).
In order to verify this, disconnect the input cables and connect your head unit with amp using a new pair. Then turn the head unit on with volume up. If it’s working with new cables, then it means the older pair was faulty.
Similarly, disconnect the amp from the speaker and connect it with another testing speaker – one amp channel at a time. If the amp is fine on all these channels, it means your speaker is faulty. This can be due to speaker wiring or a bad connection.
On the other hand, if there’s no output from the test speakers, it means the amp is faulty.
2. Check Subwoofer Settings
Most aftermarket stereos have separate subwoofer controls in the settings, which we can accidentally turn off. So you should double-check to see if the sound output is turned on and the dB level is higher than 0.
3. Make sure Amp is Mounted to a Non-Conductive Surface.
After this, you also need to ensure that no part of the amplifier is in contact with any metal of the car. This can cause many issues, such as signal clipping and amp going into protected mode.
4. Check Amp’s Ground and Power Wires
If an amp is not getting the required power from the system (in the first place), it won’t amplify audio signals. You can use a voltmeter to check your system is providing the necessary power to the amp.
To do so, connect the voltmeter to the positive and negative terminals of the amp. You should get 12V reading with the engine off and 14V with it being on.
If that is not the case, you should inspect the power and ground wires to make sure they’re not loose at any point.
5. Remote Wire Fault
The car amplifiers come with a turn-on wire (also called remote wire) used by the head unit to signal the amp to turn on – usually when you turn on the vehicle. It is usually a blue wire with a white stripe (not to be confused by a solid blue wire for power antenna – dedicated to radio only).
To test it, turn your head unit to a source other than radio, and check the voltage between the amp’s remote turn on terminals and the ground through a voltmeter. If it’s roughly 12V, then there’s no problem.
But if it’s not, change the source back to the radio and see if if you get any reading. If you do, then you only have the power antenna wire connected instead of the remote wire.
If there’s no voltage with any source (including radio), then there is an issue with your turn on wire.
Frequently Asked Questions
Why am I Getting Power to my Car Amp But Not my Subs?
It usually happens due to blown subwoofer, loose connections/wiring, or a short circuit.
What Happens if You Overpower a Subwoofer?
Many people overpower their car subs in order to get extra volume. What they don’t realize is that this extra volume will result in a distorted sound which is not only unpleasant, but can also damage your subwoofer in the long run.
Do Subwoofers Damage Car Battery?
Yes, a subwoofer can drain the car battery if you’ve turned it on for some time while the engine is off.
Is it Okay to Underpower a Sub?
While underpowering a subwoofer is not inherently bad, it will give you a weaker sound.
How do I Know if my Subwoofer is Clipping?
The most obvious sign of a clipping subwoofer is the sound distortion.
Conclusion
Alright. So these were some of the most common reasons why you’re getting no sound from subs despite your amplifier turning on.
As I said, there can be various reasons why you’re experience it. But if you’ve followed all the steps above, I’m sure you’ll find the root cause.
In case you’ve experienced any other issue that caused no sound from your sub, make sure to let me below in comments.
Read this article, extremely helpful however didn’t solve my fault. Used a multimeter. Amp power and remote fine. Replaced rcas used ac volt on multimeter can see signal on amp output it’s lower than I’d expect though. Still no sound. Either head outputs faulty (doubt) or amp or sub something is wrong for now I’m assuming the amp is bad which is real bad as it’s brand new. As is the sub and there was a sub running there prior so I figure the wirings okay too especially after experiencing the same issue with brand new rcas. Still unclear I’ll let you know if the new amp solves the problem. All speakers Jvc but the amp is sound magus so I trust that brand slightly less