I don't think that you are understanding the term ATMOS. Think of it like a newer version of Dolby Digital.
My first HT reciever did dolby surround. Then I got an upgrade to Dolby Pro Logic. This went from 3 channel to 4 channel. Two totally different technologies, but based on a method of taking a 2 channel signal and figuring out how to fool our ears and brain into thinking we are getting 4 channels of sound. we now have Pro Logic II, IIx and IIz that take the 2 channel for 5, 7 and 9 channels.
Fast forward to the Dolby Digital era. There was a quantum jump from 2 discreet channel recording to now going digital and giving 5 + .1 low frequency sub. The development continued to give us DD EX 6.1 (5.1 discrete + matrix center rear sound using technology similar to Dolby Pro Logic). those were replaced by Dolby TrueHD that gave us 7.1 discreet channels.
ATMOS fits to the side of TrueHD. To quote from Wikipedia:
Because of limited bandwidth and lack of processing power, Atmos in home theaters is not rendered the same way as in cinemas. A spatially-coded substream is added to Dolby TrueHD or Dolby Digital Plus. This substream only represents an abbreviated representation of the object-based mix. This substream does not include all 128 discrete objects separated. This is not a matrix-encoded channel, but a spatially-encoded digital channel. Atmos in home theaters can support 24.1.10 channels, and uses the spatially-encoded object audio substream to mix the audio presentation to match the installed speaker configuration. The spatial audio coding tool is applied to the cinematic object audio mix when filmmakers remix and render the TrueHD and Dolby Digital Plus soundtracks with Dolby Media Producer.
So an ATMOS receiver if given a non ATMOS track, it won't be doing anything to convert it to digital objects or anything funky like that.
What each receiver/pre-amp company does it up to them. They have the ability to do the Dolby Pro Logic like matrix conversion to drive all the speakers that are hooked up to their device. For example, Yamaha has their own Matrix 11,1 implementation that is not connected at all to Atmos. They use height speaker instead of overhead. Pioneer have their own maxtrix 7.1.4 that takes one side sound and matrix it with the other side to figure out what it thinks is overhead.
It is NOT ATMOS. It just sounds better to your ears as it makes sounds come from more directions like real life. It is like how Pro Logic sounded better than simple Dolby Suround.
All that said, a well setup 7.1 with speakers like the QS(x) speakers will send as much sound up and around to give the same effect as an GOOD install of a Matrix processed with 7.1.4 speakers. The QS speakers are effectively doing what the matrix sound process is doing in the receiver. Again, THIS IS NOT ATMOS.
