Buzzing noise


When I call outbound (didn’t try inbound), the people on the other side say that there is an kind of electric BUZZ noise when I start talking. When I stop talking it fades away.
It sometimes becomes very loud, while the next moment the noise is gone.
It is from all of my extensions (Voiper & 3CX).
The strange thing, is that I don’t hear the electric buzz, but when I record it on my 3CX Softphone I can hear the electric buzzing noise.

I’m running FreePBX on a Raspberry Ver. 11.9.0 (Raspbx) with an FritzBox 7390.
Due to the buzzing problems the system operates just fine, no packageloss, no crackels, just a nice PBX.

Am I the only one with this kind of noises?

Hope to hear from you :wink:

Kind regards,


What type of trunks are you using?

Im using trunks from Cheapconnect (

Make a test recording using Sound Recorder (Windows) or a similar app for whatever platform you are using. If the playback has the buzz, you have a problem with your mic or audio setup, unrelated to VoIP.

[quote=“Stalker, post:1, topic:22628”]
It is from all of my extensions (Voiper & 3CX).
[/quote]Do you mean Zoiper? If not, what is Voiper (other than VoIP security software)?

Don’t you have analog phone ports and a DECT base on your Fritz!Box? Do they work with your RasPBX? If so, do they have the buzz problem?

Thx Stewart1 for your reply.

I have it from all of my extensions.
Unfortunatly I don’t use analog phones of analog lines.
I all use softphone cliënts (3CX and Zoiper… not Voiper, excuse me for that one :slight_smile: )

Please confirm that audio recordings made locally (with the same microphone or headset that you use with the softphone) do not have buzz when played back.

Do calls from one extension to another have the buzz? If so, and the extensions are on the same LAN as your RasPBX, that would eliminate your provider and Internet connection. Next, temporarily configure one softphone to connect directly to another, without the PBX in the path. If that still buzzes, there may be some incompatibility between softphone and your hardware setup.

If the above doesn’t help locate the trouble, please post:
What platform(s) are you running the softphones on (Windows, Mac, Linux, Android, iOS)?
Do you have (or can you easily borrow) an analog phone or a DECT cordless phone? If so, please configure your Fritz!Box as an Asterisk extension and report whether calls from that device have buzzing.

I think I solved the problem.
There was a bad UTP connector on the Raspberry.
I’ve changed that, and had a look at the Codecs.
I also got rid of 3CX and installed Zoiper on my pc.
For now the quality is 99% super, a very little whitenoise during the calls but not mentionable.
For this moment all seems to sound very nice!
Thanks for your support so far :smile: