LAMTTO RC series wireless CarPlay devices support three audio output methods: FM Transmitter, AUX Cable, and Bluetooth (Best Sound Quality).
Audio stability is critical for navigation prompts, calls, and music playback. However, some users may experience issues such as static noise, no sound during calls, Bluetooth audio not working, and audio delay.
The good news: Most audio issues can be fixed in minutes.
Audio Output Methods Explained
FM Transmitter:
- Set a frequency on the device (e.g., FM 106.0 MHz)
- Tune your car radio to the same frequency
- Audio plays through your car speakers
- Important: The FM antenna is built into the original car charger. Always use the original charger.
AUX Cable:
- Connect the device AUX port to your car AUX input
- Direct wired audio transmission
Bluetooth (Recommended):
- Select BT output mode on the device
- Connect your phone to the car's Bluetooth
- This provides the best sound quality
Common Audio Problems & Solutions
FM Static Noise / Interference:
Use the original car charger, keep cables away from the car radio, change FM frequency, or switch to AUX or Bluetooth.
AUX Noise / Humming Sound:
Reinsert AUX cable securely, check correct AUX port, try another AUX cable, use a ground loop isolator, or switch to Bluetooth or FM.
Cannot Hear Caller (iPhone):
Check audio output and select CarPlay, tap Speaker during call to switch audio output.
Caller Cannot Hear You:
Use Bluetooth output (recommended), close windows to reduce noise, ensure voice input is enabled, and check phone audio output settings.
Echo During Calls:
Lower call volume, restart device and phone, update phone system, switch to Bluetooth mode.
Bluetooth Audio Not Working:
Restart phone, ensure correct connection order (select BT mode on device, then connect phone to car Bluetooth), test car Bluetooth independently.
Audio Delay / Call Lag:
Restart phone and device, close background apps, reset Bluetooth, try another phone.
Why Bluetooth Disconnects After Connecting
This is normal behavior. Bluetooth is used for pairing, Wi-Fi handles data transmission, and Bluetooth disconnects afterward.
When using BT mode, the audio path becomes: Phone → Car Bluetooth → Speakers
Final Thoughts
Most LAMTTO RC audio issues are caused by:
- Incorrect output settings
- Interference (FM / AUX)
- Bluetooth conflicts
- Vehicle compatibility
With the solutions above, you can fix almost all audio problems quickly. Always use the original charger (for FM stability) and keep your phone system updated.
Source: https://lamtto.com/blogs/news/lamtto-carplay-screen-audio-issues-complete-fix-guide-2026
