Docs Reference

Troubleshooting

A list that starts from the symptom. Within each heading the steps are in order of likelihood; work down from the top.

A receiver never appears in the list#

Are the receiver and the Studio on the same subnet? Multicast does not cross between subnets by default.
Does the firewall allow UDP 49000 and 49100? On Windows the network profile has to be private, not public.
Is client isolation on for the wireless network? With it on, the receiver never hears the Studio's announcement packets.
Is the receiver actually running? On a headless install, check with journalctl -u notfm-audio-receiver -f.

It is in the list but there is no sound#

Is the right audio device selected at that point? The computer's default output may have moved to another device.
Is the device set to 48 kHz stereo? A device sitting at a different rate can stay silent on the first attempt.
The receiver's level may be turned down in the Studio. Check the level in the receiver list.
The receiver may be silenced. A kick lasts sixty seconds, a ban fifteen minutes. See Managing receivers.

The sound breaks up#

Look at the packet loss column. If it sits clearly above zero, the problem is in the network.

Use 5 GHz at wireless points; 2.4 GHz raises loss in crowded places.
The multicast rate on the access point may be set too low.
If a managed switch has IGMP snooping, a querier must be present on the network.

If packet loss is near zero and the sound still breaks, the problem is on the receiver machine. Check whether something else on it is loading the CPU.

It cuts off after a while#

If the broadcast runs correctly and then stops after a few minutes, the first place to look is the IGMP setting on the switch. With no querier on the network, some switches time out multicast group membership and start cutting the stream.

There is an echo between points#

This does not mean sync has broken. Check first whether both points really are on the same broadcast, or whether one of them is in a different receiver group.

If they are in the same group and you can hear an echo, the receiver at one point may have lost its lock. Restart that receiver.

The sound is dull or squashed#

Consider that the chain may be running twice. If you are fed from a mixer with its own limiter on the output, bypass the Studio processing for that source. See Audio processing.

If the gain reduction meters run continuously, raise the thresholds.

Loudness jumps between tracks#

The leveler may be off. If it is on, check the target and speed settings. Leaving the speed slow is more stable in the long run, but correction arrives late on the first few tracks.

Transitions sound crude#

The curve may be set to linear; try equal power. The overlap limits matter too: if maximum overlap is very low, the transition ends abruptly.

If there is a long silence at the end of a track, check the gap killer's tail threshold. An untrimmed tail delays the transition.

Receivers drop during long silences#

This should not happen. The clock flows independently of audio and keeps running when the music stops. If it does happen, check whether port 49000 between the receiver and the Studio is being cut by a firewall or a power saving setting.

Power saving on wireless cards can put the link to sleep during a long silence. Turn power saving off at that point.