So I started to read this thread and read Nallehs post on daisy chaining a 2nd Atmos AVR and rushed out and bought a 2nd Atmos AVR. I set it up as TM while my other AVR ran TF and TR.
It didn't work as everything came out of the TM
I then continued to read this thread and found out other people had already found this flaw - shoulda kept reading before spending
So I then read about the little standalone Pro-Logic boxes that were posted up as a possible solution and decided to buy 3 of them. Not much was said about them after the initial couple ofposts discussing their possibilities.
But I persevered and have managed to set them up a treat :
TFR and TRR pre-outs from my 7.1.4 AVR to one PLII box, TFL and TRL to another PLII box. Boxes set to 5.1 to get the extrapolated Centre channel output.
L and R of each box to Front L&R and Surround Back L&R Multi-Channel input in my spare 7.1 AVR
Centre out of each box to input (L&R) of 3rd PL II box. Again get the extrapolated Centre Channel and now send LCR to Surround L&R and Centre of Multi-Channel input of 7.1 AVR.
This gives me TFR, TFL, TMR, TML, TRR, TRL and a VOG centre height speaker
And it works !! The beauty of this system is that you can now apply any settings you like to the 7 height speakers in the AVR as the AVR is not doing any PLII processing so doesn't care if the source is not identical. This has allowed me to reduce the VOG SPL by -9db and would also allow me to set any Auto Room Correction, speaker sizes, distances etc - or it would if I could find the remote
My room is 14.5' x 20' x 9' and my speakers are all pretty much positioned exactly to Dolby Atmos guidelines except for the TF and TR heights as they are currently mounted in the top 4 corners of the room (so Heights, not Tops) and they are at only 30deg elevation or so, not the recommended 45.
So how does it perform I hear you all asking ? Well, very well indeed. As alluded to earlier the VOG speaker was a bit dominant and at first I thought it sounded better without it, and it did sound good without, with my TMs doing a good job of phantom imaging. But I persevered again and tried different source material to compare and it turned out the first one I tried had a lot of sound naturally directed to VOG (obviously not directly as Atmos doesn't support VOG but PLII extraction had lots of stereo sounds). So I tried the Atmos demo Audiosphere clip and once I reduced the VOG SPL is was superb.
I managed to do comparison between the 4, 6 and 7 heights and just running 4 sounded really good and they did a good job of phantom imaging sounds, but 6 and then 7 sounded even better, especially for the real ambient sounds like rain fall and leaves rustling etc. Much more feeling of sound ALL around you with no gaps in the soundfield, more realistic and immersive.
Highly recommend doing this if you can, especially since my total outlay was $60 for all 3 PLII boxes, $15 for 3 mains powered USB adapters (stops the PLII boxes from humming), $20 for 3 RCA to 3.5mm Stereo cables and I paid $70 for the old Yamaha RX-V750 AVR a few years back. Total of $165. Not true 7.1.7 but pretty damn close for not much money.
And in case anyone is wondering why I went VOG - it is because it was already there from my previous AURO-3D layout and I was determined to use it