Im planning an install where i have a 10x10 HDbaseT matrix.

8x of the TV zones are using the inbuilt TV 2ch speakers.

2x of the TV zones are multi channel audio zones.

All Video sources need to be available on all TVs.

I dont want to set every source to output 2ch audio over HDMI. So my 2ch TV speaker zones, need to be able to locally downmix multi channel audio.

In the past ive done this with signal managers (this can get expensive, its another box to provide power for and hide etc)

Ive also noticed that Samsung TVs from 2017 onwards seemed to have onboard multi channel audio to 2ch audio downmixing. Ive seen some Sony's do this to.

Is there a name for this feature, so that i can check if the TVs im specifying have it ?

At the moment im choosing between LG, Sony and Samsung, not sure if the feature is called different things, by different manufactures

Wouldn’t that just be setting the TV output to PCM?
All the TVs I’ve worked with that have that.

A matrix switcher that does audio downmixing and possibly video scaling would be best. AVPro makes some of these switchers. They have an 8x8 and a 16x16 model.

You'd think one of those Samsung TVs would have a name for it in their manual. Y might have to get three or four model numbers for each brand, and then go through the manuals to see. The Samsung service company has been pretty helpful, though, so maybe a phone call would suffice for their name.

It would be nice if downmixing audio didn't cost $5K, expecially if it's just dolby digital you're looking to convert.

The cheapest TV's in the world can do it.

I agree and it might be a less expensive option to replace some of the TVs with ones that decode Dolby digital and use a less expensive switcher.