Skip to main content
Question

Sonos Amp + REL T/9x – two standby issues

  • August 17, 2026
  • 1 reply
  • 20 views

Forum|alt.badge.img

Sonos Amp + REL T/9x – two standby issues

I’m using the current Sonos Amp (125 W/channel) with a REL T/9x.

I’m experiencing two separate problems that seem to be related to the Sonos Amp going into standby / the way the subwoofer signal is handled.

1. LFE / RCA connection

When using the RCA SUB OUT from the Sonos Amp to the REL LFE input:

  • With music, the REL wakes up normally even at relatively low volume.

  • With TV, the REL often stays in standby at the same listening volume.

  • I have to increase the volume considerably before the REL wakes up.

  • Once it wakes up, it works normally.

This makes me wonder whether the Sonos Amp's subwoofer output level is different during TV playback or is simply too low at low listening levels to reliably trigger the REL's auto-wake threshold.

2. High-level connection

There is another issue when using the REL high-level connection: after the Sonos Amp has been idle/in standby for around 2 minutes, the REL produces a fairly loud thump/pop when the system changes state.

Because of this, I can't really use either solution reliably:

  • LFE only → REL doesn't reliably wake at low TV volume.

  • High-level → loud thump when the Sonos Amp goes into standby.

Has anyone with the current 125 W Sonos Amp experienced either of these issues with a third-party subwoofer, particularly a REL?

Is there a known setting, firmware issue, or recommended solution for preventing the sub from going to sleep at low TV volume and/or preventing the standby thump?

I'd really appreciate input from anyone who has solved this with the current Sonos Amp.

1 reply

Stanley_4
  • Grand Maestro
  • August 17, 2026

The external sub wakes based on the audio it sees, that is not the same when a 5.1 setup is not providing any high frequency sound to the sub connection compared to music where the sub channel is fed by a low pass filter of the music. Hook a good quality headphones to the sub out and you should hear the difference in the two sources.

Can't help with the thump.