Recording Impulse Responses for Speaker Virtualization

Jul 11, 2024 at 7:04 PM Post #1,847 of 2,034
https://drive.google.com/file/d/1L_tPoDt_5UuTTb8o8O0a6i7YppBa3fke/view

that where i downloaded the hometheatre v4 from realtek.zip>y720>Dolby Home Theater v4 EQ Software>DTPC.zip>DTPC.msi
I can access that file, but can't run setup-looks like it's specific to Lenovo (I have an Intel Nuc HTPC). I think my main problem is driver signature....looks like it always stays disabled with Windows 11 and BIOS set with Secure Boot. I'm hesitant to disable Secure Boot, but it looks like that's really the only way. The web pages I linked should work for more PCs. Since this is more complicated, I'm going to get back to experimenting at a later date.
 
Jul 11, 2024 at 9:45 PM Post #1,848 of 2,034
@Davesrose: I did an experiment with a DD+ with Atmos test track, using my A16 as a Atmos-enabled decoder and my Yamaha RX-V771 AV Receiver which supports Dolby Digital+ but no Atmos.
The test track places sound on all individual speaker positions - one at a time - of a 9.1.6 speaker layout.
When a sound is played that is intended for example for the left top middle position then the Atmos decoder of the A16 directs that sound 100% to the left top middle speaker, and nothing to any of the other speakers.
My non-atmos receiver directs that same sound 100% to the left side surround, and nothing to any of the other speakers.
That suggests to me that the sound is simply present in the left side surround channel of the basic 5.1 DD+ stream (it has to be, how else can the DD+ non-atmos receiver play it when it doesn't know what to do with Atmos information in additional streams?), and that the Atmos decoder substracts it from the left side surround channel (how else can the left side surround speaker be silent in this case?) to redirect it to the left top middle speaker.
 
Jul 11, 2024 at 10:06 PM Post #1,849 of 2,034
@Davesrose: I did an experiment with a DD+ with Atmos test track, using my A16 as a Atmos-enabled decoder and my Yamaha RX-V771 AV Receiver which supports Dolby Digital+ but no Atmos.
The test track places sound on all individual speaker positions - one at a time - of a 9.1.6 speaker layout.
When a sound is played that is intended for example for the left top middle position then the Atmos decoder of the A16 directs that sound 100% to the left top middle speaker, and nothing to any of the other speakers.
My non-atmos receiver directs that same sound 100% to the left side surround, and nothing to any of the other speakers.
That suggests to me that the sound is simply present in the left side surround channel of the basic 5.1 DD+ stream (it has to be, how else can the DD+ non-atmos receiver play it when it doesn't know what to do with Atmos information in additional streams?), and that the Atmos decoder substracts it from the left side surround channel (how else can the left side surround speaker be silent in this case?) to redirect it to the left top middle speaker.
I don't understand why you'd think the sound wouldn't be on left side surround on a non Atmos system. I've been trying to indicate that when the ADM sound file gets rendered to DD+ Atmos in a movie file, there's a legacy 5.1 surround track. It has all audio channels for FL, C, FR, RL, RR (and if you have a legacy 7.1 speaker system, the receiver matrixes the RL with SL and RR with SR). I think maybe where hasn't been clarity-I've been saying that the Atmos decoder in the receiver (or A16) is interpreting the surround stream along with the JOC stream to first determine where the sound is in 3D space, and then maps that to what speakers you have. So even though a 5.1 stream might have a sound rear left, the Atmos decoder uses positional data to know what's intended for a height speaker with Atmos. You also indicated a theory about Atmos decoding using ratios in determining pans to speakers that aren't present in surround. From literature I've read, I think it's more complicated in order to be more versatile. When you setup a receiver, it has its microphone that sets each speakers characteristics (level from distance, crossover level for LFE, bass management, etc). If the Atmos decoder first renders an object based 3D field, it's easier to rely on the receiver's speaker config to map to each speaker. The concept is also more necessary with cinemas having a larger space and more speakers.
 
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Jul 11, 2024 at 10:18 PM Post #1,850 of 2,034
I don't understand why you'd think the sound wouldn't be on left side surround on a non Atmos system. I've been trying to indicate that when the ADM sound file gets rendered to DD+ Atmos in a movie file, there's a legacy 5.1 surround track. It has all audio channels for FL, C, FR, RL, RR (and if you have a legacy 7.1 speaker system, the receiver matrixes the RL with SL and RR with SR). I think maybe where hasn't been clarity-I've been saying that the Atmos decoder in the receiver (or A16) is interpreting the surround stream along with the JOC stream to first determine where the sound is in 3D space, and then maps that to what speakers you have. So even though a 5.1 stream might have a sound rear left, the Atmos decoder uses positional data to know what's intended for a height speaker with Atmos.
I already thought is was just a misunderstanding. When you answered "no" to one of my questions ("are they audible if the track is played with a normal Dolby Digital or TrueHD decoder ...") I understood that as "no, they are not audible" but I guess the "no" was about the second part ("or are they simply not audible when played by a normal Dolby Digital or trueHD decoder?"). Everything is clear now I think?
 
Jul 11, 2024 at 10:38 PM Post #1,851 of 2,034
You also indicated a theory about Atmos decoding using ratios in determining pans to speakers that aren't present in surround. From literature I've read, I think it's more complicated in order to be more versatile. When you setup a receiver, it has its microphone that sets each speakers characteristics (level from distance, crossover level for LFE, bass management, etc). If the Atmos decoder first renders an object based 3D field, it's easier to rely on the receiver's speaker config to map to each speaker. The concept is also more necessary with cinemas having a larger space and more speakers.
Of course I formulated it a bit simplified, of course in my example the 0.5 * Y to one and 0.5 * Y to another speaker would have to be refined with the proper application of level and delay etc. according to the speaker set-up.
 
Jul 11, 2024 at 10:39 PM Post #1,852 of 2,034
I already thought is was just a misunderstanding. When you answered "no" to one of my questions ("are they audible if the track is played with a normal Dolby Digital or TrueHD decoder ...") I understood that as "no, they are not audible" but I guess the "no" was about the second part ("or are they simply not audible when played by a normal Dolby Digital or trueHD decoder?"). Everything is clear now I think?
Referring back to your question and my answer, I think my no was that "positional sounds" wouldn't be present in the legacy 5.1 stream. I also hadn't had my morning coffee😊. But technically the JOC is positional data and not sounds (and makes this difficult to conceptualize) 😀. That's what I find interesting from a software development side: there must be some sophisticated programming to be able to render out a base 5.1 layer that's compatible with legacy systems. Then use the JOC to create objects, take the audio channels for sound characteristics, and map them to the objects for a system that has an Atmos decoder.
 
Jul 11, 2024 at 10:51 PM Post #1,853 of 2,034
Of course I formulated it a bit simplified, of course in my example the 0.5 * Y to one and 0.5 * Y to another speaker would have to be refined with the proper application of level and delay etc. according to the speaker set-up.
I think Dolby formulated the 3D object field approach to make it easier to map any given number of audio channels to a 3D space. I haven't been able to find much info with Dolby's new Dolby Surround format that's on Atmos systems (that takes a 5.1 or 7.1 movie and "matrixes" it to 3D). Or maybe it uses certain algorithms to figure out where that sound is in space, and renders a 3D object field like Atmos. Giving how convincingly it (and DTS:Neural) places objects that should be up above, it's either sophisticated matrixing or utilizing methods for first rendering to 3D audio.
 
Jul 26, 2024 at 4:11 PM Post #1,854 of 2,034
Someone really needs to try the Home theatre driver with a Dolby atmos device and Dolby access to replicate what im getting. I'm convinced I am getting atmos. The sounds from dolby demos are Binaural close and far. I know what everyone is saying that it hasnt been done and lav filter or something else would stop atmos in its tracks but I'm getting atmos for certain height channels the works.

Just to reiterate I have
.
Headphones connected to 3.5mm jack on the back of tv
Dolby Atmos tv connected to pc via hdmi arc port.
Dolby access installed.
Dolby Home Theatre v4 driver hacked into the lg tv driver. make sure the on button in the corner is highlighted
mpc hc with lav filter (Lav is not needed) set audio output to voicemeter input (vb - audio voicemeter vaio)
I was using vbcable But voice meter sounds better
In Voicemeter banana set A1 to lg tv and also set lg tv set soudn device to MME (Mutimedia)
Windows sound options set both voicemeter and lg tv to 7.1 (once dolby access is activated the lg setting will change from 7.1 to atmos.) also will show on tv that it is getting atmos not pcm
lg tv is set to default device in windows sound options (for dolby access to work.. cant get access to work with voice meter)
in hesuvi voicemeter is ticked in device filter
in windows sound options > recording tab > double click voicemeter out a1 > listen tab > ticked listen to device and select the atmos device (lg tv) > advance tab set to 24 48000hz 2 ch.
eqapo set device to voicemeter input (vb - audio voicemeter vaio) and channel config to device default 7.1
open whichever application you want to use so it pops up in windows sound > volume mixer > and select output device to voicemeter.

I would not be going on and on about this if it wasnt working. People spend lots of money for atmos system and you guys are already half way there. So if someone has this equipment please try these settings.
 
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Jul 26, 2024 at 5:57 PM Post #1,855 of 2,034
I can't see how you're listening to Atmos, when Dolby is very specific that Home Theater V4 is a surround virtualization for stereo speakers or headphones. Dolby says that it will up mix content to 7.1 (not 7.1.4). I'm not sure what Dolby Access would do that's different from using Windows device manager and setting the sound card to 7.1. When you showed your screenshot of Dolby Access, for example, it showed a surround setup. If I use it through my Atmos receiver, I see a 7.1.4 setup.

Dolby Home Theater v4
 
Jul 26, 2024 at 6:29 PM Post #1,856 of 2,034
Dolby access shows the toggle for height channels maybe thats what is giving me the height andselecting dolby access is whats giving me the atmos option in windows. Not sure how the hometheatre v4 is playing a part in this but after i installed it I got more supported formats
1722032784332.png

1722032825956.png


this is what i get when i activate dolby access


1722032887536.png


This youtuber has this demo to test height speakers. In it he moves the sound from the standard level surround to height corners and above the head. He also moves the sound from above the head diagonally down to the centre front and you can hear it move exactly. All the height corners and top sound perfect too. Heres the link to that video. Not the youtbe link because that wont play atmos
https://www.dropbox.com/scl/fi/ueko....mp4?rlkey=skou46t6c6qqbufaxla68fu8w&e=1&dl=0

blade runner new movie the bee scene. I close my eyes and the bee's are hovering and flying inch's in front of me and side then flying away and i can follow there movement by sound. Normal surround gives that impression but not like this its so real.
 
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Jul 26, 2024 at 8:14 PM Post #1,857 of 2,034
I downloaded the movie: on my HTPC going HDMI to my 7.1.4 speaker system, I confirmed that the sounds went to the proper speakers (though he seemed to mix the left and right speakers to be quieter than the height speakers. My receiver also confirms its Atmos mode.

Due to Dolby's literature on Home Theater V4 being a virtualization for 7.1 (not Atmos), I'm still going to believe them. Maybe your experiments with Dolby Access are somehow doing a better job of matrixing the height channels in a true Atmos source to the 7.1 that Home Theater 4 is processing. From what I've tried, it's been hard for me to try to get Theater installed, with my device drivers with my Intel NUC. It also messed up my sound driver for getting sound to my receiver-so I've tried reverting to just using Dolby Atmos for my speaker system.
 
Jul 27, 2024 at 2:30 AM Post #1,858 of 2,034
I can see why you might not want to try if it’s messed up your drivers. But it’s definitely worth it once it’s working

I think it is important to use the home theatre v4 only specifically on the driver auto installed from the atmos device. That’s why I’m pushing my lg tv in the guide. So if anyone has a lg tv with atmos they can try.

It was easy for me to remove the installed hacked driver many times during my experimenting. You must already know but just incase I uninstalled it through device manager.
 
Jul 27, 2024 at 5:54 AM Post #1,859 of 2,034
I downloaded the movie: on my HTPC going HDMI to my 7.1.4 speaker system, I confirmed that the sounds went to the proper speakers (though he seemed to mix the left and right speakers to be quieter than the height speakers.

I used cavern to test the audio. In the headphone mode that supports all the channels he is showing in the video the speakers are at the same level. Using 7.1.4 there are some differences in the levels probably due to the fact that 7.1.4 does not include all channels he used in the mix. Playing the file with MPC results in 5.1 output. Back and middle height channel is played at LS/RS.
 
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