Scope decides who owns the fault, and finding it takes under a minute. Play three channels from three different categories. One silent channel with healthy neighbors means that single source feed carries an audio track your setup cannot decode, and no menu on your device changes what the encoder sent. Every channel inside one category silent, other categories fine, means the audio profile for that whole group is wrong at the server, which is a support ticket rather than a settings hunt. Silence across everything, including app menu sounds and other apps, means your output chain: device volume, TV audio format, or the HDMI handshake. Three symptoms, three owners. Guides that open with decoder settings send you chasing a fault you cannot reach.

1. 1One channel silent: source feed encoding
2. 2One category silent: server-side audio profile
3. 3Everything silent: your device or audio output chain

Passthrough is the mechanism almost nobody explains properly. In passthrough mode the player does not decode audio at all. It forwards the compressed bitstream to the TV, soundbar, or receiver and assumes that hardware knows what to do with it. When the receiving device has no AC3 or E-AC3 decoder, there is nothing to fall back on, so you get exact silence rather than distortion or low volume. Many live feeds carry AC3 on primary channels and AAC on secondary or regional ones, which is precisely why some channels sound fine and others do not on the same device, in the same app, on the same evening.

1. 1Passthrough forwards, it does not decode
2. 2AAC channels play, AC3 channels go silent on the same device
3. 3Software decoding puts the work back on the player

Switch to another channel, wait five seconds, switch back. If audio returns, the codec was never the problem: the session dropped the audio stream mid-playback and the reconnect rebuilt it. That result rules out your decoder settings, your soundbar, and your bandwidth in one move, and it means the fix is a reconnect rather than a configuration change. If the channel comes back just as silent every time, the audio format or the source itself is the cause and you can move on to decoder and output settings with confidence. This test costs nothing, discriminates better than any restart, and is missing from every ranking page we read on this topic.

1. 1Sound returns on switch-back: session-level drop
2. 2Still silent on switch-back: format or source

Set the player to software decoding for audio, and set the TV or soundbar audio output to PCM. Software decoding makes the app decode AC3 itself and send plain audio downstream, which sidesteps every hardware gap in the chain. PCM output stops the TV from renegotiating a compressed format the receiver will not accept. Between them these two cover the large majority of silent-channel reports on Firestick, Android TV, MAG boxes, and Smart TV apps. If a channel offers more than one audio track, cycle tracks too, because a secondary commentary track can be present but carry no usable audio. Play the same channel once in VLC to separate a player fault from a source fault.

1. 1Audio decoder: software, not hardware or auto
2. 2TV or soundbar output: PCM rather than bitstream
3. 3Cycle audio tracks before assuming the feed is broken

Some silent channels are genuinely server-side. If an entire category lost audio at the same moment for everyone, the transcode profile or audio PID for that node is wrong, and every decoder setting you change is wasted effort. Conceding that is not a cop-out, it is the reason to ask any service a checkable question before you pay: what uptime do you publish, and how fast does support answer a group-level fault. We publish 99.99%, which works out to roughly 53 minutes of downtime a year, and we serve 54,000+ live channels across 190+ countries to 31,000+ subscribers. Numbers you can hold a service to beat adjectives every time.

1. 1A whole category losing audio at once is not a device fault
2. 2Ask for a published uptime figure, not a promise