Originally Posted by Marc Alexander
This is only if there is no designated Top/VoG speaker(s). Please provide link if otherwise.
I was going by memory and have no idea where to locate what I read as it was over a year ago. However, I figured an easier way to check was to set my AVR to use 5 overheads and compare to 4 overheads (no VOG speaker connection needed). It seems what I read was either only half right or may pertain to a different decoder (e.g. Trinnov, Storm, etc.).
Here, on the Marantz 7012, with 5 overheads (FH + RH + VOG enabled), the front heights do indeed continue to also play the VOG tone (creating a 3-channel array between the front heights and one assumes a single VOG speaker), but the rear heights/surround height do not play. With only 4 overheads (FH + RH), they all play. I find this oddly troubling in a sense because using half the front height speakers will result in an arrayed phantom image in front of the VOG location whereas using front/rear height results in an image pretty much dead center between the two (mid-point of a typical room layout). Now using front height + surround height could result in the same phantom image as the front height + VOG speaker, but the 7012 makes no differentiation between the two (i.e. the output for rear height is always identical to surround height which allows me to use a switchbox to swap them to get "true" Auro-3D in the front half the room if desired as my side heights are right above my side surrounds). I verified this yet again by running the same test with front height + surround height instead.
The issue is that front height + VOG (assuming even levels), would be the first 1/4 of the ceiling (assuming an even speaker distribution) as would front height + surround height without the VOG. But front height + rear height would be the mid-way point of the room. Thus, it would make more sense if the AVR used all 5 overheads with FH+RH+VOG but only 3 (FH+VOG) with surround heights enabled. But this could be a limitation of the firmware in the 7012 (i.e. cheap and dirty compatibility setting to work with rear height, which is why they say it's not optimal). It's possible a Trinnov would/could behave differently making the rear height option more optimal, but I think it already has options to remap speaker locations beyond any single decoder mode.
Now whether you'd want "above you" to be in front of you, I cannot say ("directly above you" sounds more like right above my head so again, the AVR behavior is a bit troubling relative to the announcement in the demo using "Pure Auro-3D" here, but I do prefer it to be right above my head give or take a foot or two. So it seems like adding a true VOG channel speaker would only shove the image forward whereas with FH + RH (and even FH + extracted TM + RH) I get the "VOG" more or less directly overhead. If I do want it forward, I can just swap rear heights for the top middle (side height) speakers and the VOG does indeed image in front of me at about the 45-50 degree (i.e. top front if it were installed) location. If I duplicate side height and rear height, it pulls the image back a bit (due to precedence, not 3/4 back, but about the mid-point of the room (i.e. my MLP is at the 38% location so slightly above and behind me as opposed to a few feet in front of me with only surround height
Ironically, using "Scatmos" extracted "Top Middle" with the AVR set to 4 heights gives me output for the VOG from ALL SIX overhead speakers from Auro-3D in the test. So in a way, I already do have a 6-channel overhead array option like the table suggests. All in all, that gives me 3 different Auro-3D playback options (technically 4 if I bypassed the extraction processors using their bypass mode).
Auro VOG effects here sitting at the 37% point in a 24' room with heights and top middle available:
1> FH + RH (TM bypass)
--- Results in VOG almost
directly overhead (slightly forward due to sitting closer to the front), but more dispersed due to the long angle. From other seats, it pulls towards the nearer speaker (precedence) so in the middle row it's almost overhead and the back it's still almost overhead, but slightly behind and more distinct since you're much closer to the rear heights.
2> FH + TM + RH (6ch VOG array)
-- Results in the VOG nearly directly overhead and distinct (from the second row, it pulls back a little due to precedence, but above in front and almost directly at the mid-point of the room and at a point further back but just in front of and above the back row seat). So it's always nearly directly overhead wherever you sit (array effect) relative to you, but moves along the line back through the room.
3> FH + SH (rear disabled)
-- Results in the VOG being about 1/4 into the room overhead (about where top front would be more or less). Mid row, pulls towards middle. Rear row, sounds like the ceiling in the middle of the room far in front of the chair.
4> FH + SH + RH
(RH/SH run in parallel via switchbox which emulates uses an array of "surround heights" like the cinema, except they obviously have a real VOG speaker array too which may not use these then if they act like the 7012) -- With VOG only, it behaves like the 6CH array as it IS the 6CH array again for just that speaker. But for using the heights to pan, it acts like having a set of speakers 2/3 into the room for the 2nd/3rd rows, but doesn't move that much for the front row due to precedence near the top middle speaker locale (does seem 1.5-2dB louder or so now though)
Those are the results I can get in my own home theater. If I added the VOG
, I would likely get:
5> FG + VOG (SH/RH disabled by AVR)
-- VOG appears to image in front of and above the MLP (how far depends on how loud the VOG is relative to the front heights, but it would be more or less just like #3
above. (From the second and third rows, it would sound much like #3
Originally Posted by Marc Alexander
They are at a lower volume because multiple speakers are reproducing the Top/Vog. I would expect -6dB/each with 4 heights configured.
I was referring to the overall volume in that part of the demo with all four speakers active being lower than when the guy is speaking in those various speakers, not the level of a single speaker (i.e. I don't have the VOG speaker connected to compare, just the volume of the other speakers). It's possible it's the demo itself, however. Sadly, the Auro-3D provided tones on their demo discs are sine wave tones, which are difficult to get an exact reading as moving the meter even slightly greatly alters the reading, but to my ears, it sounded much closer to even with a sine tone with all four playing than when the video says, "and also above you" that is sent to the VOG channel. Pink noise would have been preferable to verify the levels more easily.