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How to Fix Low Volume on FM Transmitter – (Solved)

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An FM transmitter is the best life-support system you can gift your car with an outdated audio system. It’s a cost-effective way of upgrading the music system without having to spend a fortune on expensive equipment. The value you get from such a small device is unthinkable but the system is not always foolproof. Problems range from persistent static noise to low volume and in this guide, I will show you how you can fix them.

The best way to fix low volume on an FM transmitter is by resetting the device and decreasing the audio to zero. Then, you need to increase the volume gradually until you get a proper response from the transmitter.

Given their size it’s quite common to encounter issues with a Bluetooth transmitter. Some transmitters disconnect, accidentally pick up other stations, and become less audible during playback. If you are facing such issues, these tips can help you fix the issue.

Can a broken dial cause low volume?

Yes, a broken dial can cause low volume or in worse cases even distortions. The best way to address the issue is to get a new transmitter especially since they are very cheap.

I have been using the Nulaxy KM18 Bluetooth FM transmitter for the past four years and the device has been working fine, until last month. The audio fluctuates uncontrollably every time I touch the dial. It also gives out a bit of static noise when I make contact with the dial. Here is how you can check if the low volume issue is connected to the dial.


1. Nudge the dial and listen if the audio fluctuates.

2. Check if the audio increases/decreases uncontrollably when you rotate it.

3. Check for distortions when you touch the dial.

If all of the above solutions failed then it’s time to get a new one. Radio transmitters are quite cheap and it’s more worthwhile to replace one rather than repair it.

Can weak signal strength cause low volume?

Yes, weak signal strength can cause the volume to decrease. It usually happens when the transmitter is close to a strong enough radio channel, causing the signal to bleed into the transmitter.

FM transmitters are similar to mobile radio stations. They emit a frequency that is picked up by the car’s radio and you connect to the transmitter via Bluetooth. Now anything you play on your phone is played through the car’s radio unit. The transmitter becomes your personal broadcasting station and they are used in cars that do not support Bluetooth in their audio system.

It’s a smart solution to an otherwise complicated problem since it is very expensive to install a Bluetooth-supported audio unit. The transmitter and the radio have to be on the same frequency, but you need to make sure that’s not an active channel. So if your selected frequency is close to an active channel, it can cause problems causing low volume, and here is how you can fix the issue.


1. Go to the FM Channel Finder website and enter your ZIP code.

2. The website suggests all possible radio frequencies that are available in that location which you can use to connect your car’s radio and transmitter.

3. So if your ZIP code is 70092 the best frequency for your transmitter is 103.7 with 103.5, 102.5, 98.9, and 91.3 being close alternatives.

The site provides the best frequencies you can use to transmit music to your radio. It also maximizes your signal strength and reduces your chances of bumping into another radio-active radio channel. The website has helped me enjoy uninterrupted music so far without any interruptions.

How to maximize sound quality and volume for your FM transmitter?

A ground loop interrupter improves audio quality, reduces distortions, and increases the volume by a decent level. It’s a 3.5/aux cable that connects both the transmitter and the car’s radio unit.

Did you know that charging your phone while being connected to an FM transmitter can cause distortions and even lower the volume? The difference is minuscule and is hardly noticeable, but is worth looking into if you want to maximize the volume output. Here are a few more things you can do to increase volume and get the most out of your transmitter.


1. Tune the volume of your phone, transmitter, and car radio and set them to the middle. Now adjust each and check which one of the controllers is the most effective (affects the volume with the least distortion) and use that to adjust the volume from now on.

2. Sometimes it’s best to tune closer to a very faint radio station rather than blind static noise. The trick compensates for distortion and can slightly enhance the audio quality and volume.

3. Go to Radio-locator to find out which channel(s) are available in your region, and keep changing the frequencies until you land on one with the highest volume and clarity.

Every transmitter is different and the more expensive ones come with additional features to help you pump out more volume. The Nulaxy KM30 Bluetooth adapter comes preloaded with a treble and bass mode. You can also adjust those settings to squeeze out more volume and better quality audio. I recently upgraded to the KM30 and the audio output has improved remarkably. So if you are looking for an FM transmitter, I highly recommend this one.

How to properly set up an FM transmitter?

To set up an FM transmitter you will have to plug it into your car’s power port and tune it to the right channel. Here are the steps to do so:


1. Plug the FM transmitter into your car.

2. Note the frequency that’s on the transmitter. 

3. Tune your car’s radio to that same frequency.

4. Open Bluetooth settings on your phone and connect to the transmitter.

5. Now everything you play on your phone should sound through the car’s speakers

6. If you hear distortions, change the frequency on your transmitter and the radio. Use FM Channel Finder to find the best broadcasting frequency for your location.

Setting up a power port is quite easy, the difficult part is choosing the right one and I will show you how to pick one in the FAQ section.


How to pick an FM transmitter?

Make a list of your requirements and compare the specs before buying the device.

1. For instance, all transmitters have an external port so that you can charge your phones or power something else. The cheaper ones are not all that effective and take a long time to charge your phones. The Nulaxy KM30 supports QC3.0 fast charging which is 4 times faster than normal chargers.

2. The KM30 has a better speaker and mic, produces better audio, and in general is a lot louder compared to the KM18, making it a must-have for audiophiles.

3. The port location is also a factor you should consider while buying an FM transmitter. I prefer transmitters where the USB ports are at the top rather than the sides. But you may want something different based on your car’s power port location.


FM transmitters are the perfect solution to your age-old audio car audio system. However, the little device can only do so much. For instance, they are not that helpful in metropolitan areas like New York, where you will have a hard time finding a broadcasting frequency. So if you plan to buy one, make sure you scout your location first to assess the effectiveness of the transmitter. Hopefully, you have found this article helpful, and stay tuned for more tech tips in the future.

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