The Speech Enhancement setting is enabled perhaps? Or Night Sound? Did you Trueplay tune it? 

What’s specifically wrong with the sound you’re currently getting? Note that the Beam wasn’t designed for near-field listening so you’re likely to have to tweak the EQ come what may.

You also might want to pull the Beam forwards somewhat. It looks like some of the sound could bounce around behind the screen.

The sound loses bass, scale, weight, clarity, volume, etc. It’s almost like some sort of heavy compression happens. Like the old Bluetooth codecs. I only have TruePlay enabled. Disabling it doesn’t fix the issue. The App shows PCM Stereo.

I don’t think placement is an issue since I don’t have any problems when I’m streaming wirelessly. It must be something with the wired connection and the Audio Adapter that I’m using doesn’t probably play well with Sonos. I’ll try with another adapter.

It’s strange that the Bose 300 soundbar doesn’t have this issue. That’s a shame since the Beam does sound better in general. 

Wondering if I should try this adapter since it has HDMI i2S output. 

The first 4 could be explained by the last. The volume levels you need to set for TV input and for streaming sources are very unlikely to match. The human auditory system perceives higher volume as ‘better’ and that’s accompanied by a perception of increased bass, weight, clarity, etc.

Beam requires HDMI-ARC/eARC. 

Thanks. I was out of ideas until I rebooted my iMac and powered cycled the Beam and my USB to TOSLINK adapter. One of these did the trick and the Beam now sounds similar over wired connection and wireless streaming.