I had a Playbar for years and loved the sound of the speaker. It was well balanced for TV and music. I got an Arc for Christmas in 2023, and was so unimpressed at first because the Arc is definitely not as warm as the Playbar, by itself. I almost put the Playbar back, but decided to add the Sub and surrounds. That is when the Arc began to shine as it filled the room like in a way the Playbar couldn't. The high frequencies were still a bit harsh so I reduces the treble for the room to -2. That setting has made the Arc a treat to listen to.

While the center channel on the Arc is not close to what you are describing with the Ultra, I would still give cutting the treble a bit to see if it helps.

Thanks for the reply, I had an original Arc it was fine. Upgraded to Ultra and the centre channel is ridiculous, either that or the left and right channels are lowered for some reason. There is a test Sonos asked me to do, set volume to 1 and re check, at that volume you are unable to hear left/right, but you can clearly hear the centre...Surely I can’t be the only person or reviewer to notice this, it’s an insanely dramatic difference.