So in a job I am doing I will be replacing two old key digital matrix's with an atlona pro model with 6 i/o's and 4 audio breakouts. There are 4 tv's. One TV will be using a marantz sr7012 surround receiver connected to the matrix. For sources i'll have two cable boxes, two apple tvs and a bluray going into the matrix. 4 TV's, all 1080p.

This is my first time doing a matrix with a surround receiver in there and I got reading about lowest common denominator with audio and surround receivers connected to a matrix. Basically that if a regular tv is turned on first then the zone with the marantz is turned on that zone could actually not receive audio and you'll get no sound if its look for multichannel audio???

How does one generally go about handling this situation and making it work seamless every time?

I'd try using the HDMI first.

If that doesn't work as well as you want then you have 4 digital inputs you can use.

We have dozens of systems deployed with surround sounds and matrix switchers. We have never experienced the issue you are referring to, however, we do not use Atlona products. Does the Atlona matrix you will be using have a mirrored HDMI / HDBT output? We have used Key Digital, Wyrestorm and Crestron DM successfully in the mentioned scenario.

Yes mirrored. It wasn’t atlona specific I read this about. They were portraying all matrixs had this issue. Here’s the article [Link: support.hdanywhere.com]