Recording Impulse Responses for Speaker Virtualization

[sander99]

when I used the hacked driver to put Dolby into my lg tv driver on pc

I really don't know what you are doing.
You have something running on your pc that does something Atmos related to the audio before it goes to HeSuVi?

 

[morgin]

The hacked driver is just giving me more formats on my lg sounds tab. It’s giving me home theatre v4. That Dolby tab in the sound option isn’t normally there on the original driver.

Also I understand there’s a lot of upmixing going on in different softwares that I am using. But it genuinely does not sound fake or perceived illusion sounds. Otherwise it would just be an opinion on how upmix sounds to me. It is perfect accurate placing all sounds and their echos

 

[Davesrose]

are they audible if the track is played with a normal Dolby Digital or TrueHD decoder (and "moved" out of there to be panned to other speakers when played by an Atmos decoder), or are they simply not audible when played by a normal Dolby Digital or trueHD decoder?

No, as I indicated, an older system (without Atmos) would just see the surround stream (DD+ or TrueHD). If it is an Atmos system, it takes the two streams (JOC and DD+/TrueHD) and can map to any number of speakers (stereo, 5.1.2, 9.2.6, etc).

 

[Davesrose]

It’s very very convincing I know it’s mixed to give me the height effect because I never recorded any height speakers. But it sounds as good as my other speakers in front, back or side etc.

My receiver, that supports Atmos/DTS:X/Auro-3D, also can interpret some convincing height channels with 5.1/7.1 content and (using DTS:Nueral/Dolby Surround). With 5.1 DTS-MA Master and Commander, for example, it can upconvert and place convincing sounds of people above deck (also have heard similar placement with 5.1 audio and helicopter blades being above). So it is pretty impressive about what algorithms are used to simulate 3D (whether your source is natively 3D or not).

 

[Davesrose]

I just looked up HeSuVi headphone surround virtualization. It looks like it doesn't support Dolby Atmos (I'm seeing threads comparing it with Windows Dolby Atmos codec). From what I can tell, there are folks that have experimented with middleware that can read the JOC Atmos stream, and mix the 3D content in 6/8 channels. By itself, if you're using HeSuVi first, and sending to an LG TV through HDMI (lossless surround) or coax (lossy surrround), it would be ignoring the Atmos JOC but doing it's own virtual processing for overhead effects. I suppose, then, if you're sending the binaural stereo signal to the TV, it's keeping it stereo if you're connecting your headphones to it (instead of it doing its own surround processing to stereo). If you were using the Dolby Atmos codec, it decodes the whole Atmos track (and for headphones, has a basic HRTF to create a binaural signal). A lot of new TVs do have an Atmos decoder in them. They also now have eArc (which supports TrueHD input). If you are playing through VLC, and have settings correct as well as output set as the TV, you can bitsream the Atmos to the TV for it to decode Atmos. Have never tried hooking my headphones up to my TV to see how it handles the headphone out for Atmos headphone. I have a 2018 LG OLED in my main room, and a 2022 LG OLED in my bedroom. I have tried headphones on my laptop with Atmos content (and Atmos Windows codec), and for my ears, didn't hear surround sound (because there's no ear calibration with Windows Dolby headphone).

Since I have a HTPC (going through my receiver and then going to ARC HDMI of my LG TV), I could try replicating your setup to see if I can hear a convincing 3D headphone effect with headphone output of my LG TV. It's possible that the LG driver has a better HRTF than the canned one supplied by Dolby. If you link to the different software/drivers you're using, I can see if I can use them on one of my setups. I have content on my NAS that's both TrueHD Atmos and DD+ Atmos.

 

[sander99]

as I indicated, an older system (without Atmos) would just see the surround stream (DD+ or TrueHD). If it is an Atmos system, it takes the two streams (JOC and DD+/TrueHD) and can map to any number of speakers (stereo, 5.1.2, 9.2.6, etc).

I understand that, but left out the "No, " because I don't know if you fully understood what I meant, and what I meant doesn't necessarily contradict what you are saying.
What could be done is the following:
You could put all the sound in the standard surround stream, and just put difference signals with location information in the objects in the additional (JOC) stream(s).
So for example in the regular left front channel you could have some signal X + Y, and played back on a regular non-atmos system you would hear X + Y out of the left front speaker. And an object could contain signal Y with location information: azimuth 30 degrees left, elevation 30 degrees up, and in what channel or channels of the standard surround stream Y is already present. Then when an atmos decoder is used it can substract 0.5*Y from the signal for the front left channel, so X+0.5*Y remains, and send 0.5*Y to the front left top speaker (if that is at 60 degrees elevation). Then Y would be panned halfway between those 2 speakers. This is just an example. In general you could say: susbstract Y from the normal channel(s) where it is present and re-divide/pan it appropiately over the available speakers.
This way that particular sound is always played somewhere, if not in the proper location on a non-atmos system. I find it hard to believe that instead Dolby would do it in a way such that certain sounds simply are completely left out on a non-atmos system. I would hardly call it compatible with non-atmos systems then. And difficult to get the overall balance right on both non-atmos and atmos systems.
But I simply don't know what they do exactly, so still you could be completely right.

 

[Davesrose]

I understand that, but left out the "No, " because I don't know if you fully understood what I meant, and what I meant doesn't necessarily contradict what you are saying.
What could be done is the following:
You could put all the sound in the standard surround stream, and just put difference signals with location information in the objects in the additional (JOC) stream(s).
So for example in the regular left front channel you could have some signal X + Y, and played back on a regular non-atmos system you would hear X + Y out of the left front speaker. And an object could contain signal Y with location information: azimuth 30 degrees left, elevation 30 degrees up, and in what channel or channels of the standard surround stream Y is already present. Then when an atmos decoder is used it can substract 0.5*Y from the signal for the front left channel, so X+0.5*Y remains, and send 0.5*Y to the front left top speaker (if that is at 60 degrees elevation). Then Y would be panned halfway between those 2 speakers. This is just an example. In general you could say: susbstract Y from the normal channel(s) where it is present and re-divide/pan it appropiately over the available speakers.
This way that particular sound is always played somewhere, if not in the proper location on a non-atmos system. I find it hard to believe that instead Dolby would do it in a way such that certain sounds simply are completely left out on a non-atmos system. I would hardly call it compatible with non-atmos systems then. And difficult to get the overall balance right on both non-atmos and atmos systems.
But I simply don't know what they do exactly, so still you could be completely right.

This is from what I've seen in video data I've processed, and reading what Dolby says themselves. So when a project is mixed in Atmos, the video firm that encodes the movie (for streaming or UHD disc) gets an ADM file (that has it's own number of 2D surround "bed" of audio channels and up to 128 positional objects). The audio that's rendered for home distribution is two streams. The legacy 5.1/7.1 surround stream (which is needed for non Atmos systems to recognize and play as DD+/TrueHD), and the JOC (which at any point in time can have up to 16 channels or objects). The legacy system can't read or interpret the extra positional information. The Atmos system needs both streams. It can interpret the surround stream as the 2D axis, include the JOC, to first simulate a 3D field. At that point, it's using object data to figure where something is in space. It's using the audio channels to give the objects the necessary sound attributes. With a receiver that has its calibrated speaker setup, it then maps to it (that can take into account number of speakers, crossover range, speaker distance for level adjustment, etc). There's some other steps for taking the 3D field and applying a HRTF for binaural stereo.

The way I see it, this is the approach that makes most sense for distribution. Older systems can still read this audio track as standard DD+/TrueHD. Since it's the main source for audio channels, and the 2D surround field, they are not *losing surround information*. With Atmos systems, you get what is intended for Atmos: being able to map individual sounds to any speaker (that creating a 3D space is an additional process). Atmos was first intended with cinema, which previously had arrays of speakers that played the same channel. Now Atmos is more versatile where it can map individualized sound to each speaker. Atmos doesn't have to be as versatile for a home theater setup, but the concept is still there as far as taking 5.1 DD+ Atmos material and mapping to 9.2.4.

 

[morgin]

Ok so my set up goes as following there’s gonna be lots of pictures too. Incase someone in future wants to try replicate it.

Lg cx (Dolby atmos capable) Tv connected pc via hdmi 2.1 cable into earc port. (Lg tv setting.. sound/additional settings/hdmi bitstream).

Headphones connected to back of tv 3.5 mm jack.

Vbaudio cable set up with hesuvi. Set this in windows sound options to 7.1. And listening to the lg tv.

Download custom resolution utility and in Extention blocks double click the text. Then look for audio formats select all you want and set to maximum channels. Save and then restart64.exe to reboot audio drivers.

delete all audio driver besides vbaudio cable, disable driver signature and restart pc.

select lg tv as default sound device and then use the file provided to install DTPC.msi, this will give dolby tab in the lg windows sound settings and home theatre v4 in taskbar. (play audio and toglle on off from both places to see if it is working.. mine took a few attempts at install till it worked. note the formats in lg tv windows sound options will change and will have more dolby formats listed. note also the name will change to somehing like lg tv (dolby home theatre v4 nvidia)

Download Dolby access will need to pay but it’s not expensive. It will only activate when setting lg tv as default sound device. select home theatre and toggle on the height option. If connected properly it will show dolby atmos on the tv.

Vlc player does work but mpc hc with lav filters gives me better atmos. Try to copy the full settings on CRU, Mpc Hc and Lav filter (Also lav filter has both internal and external so try and set both because my system i would change one but forget the other and im not sure which is being used at one time.) use the latest version of these programs.

I will put all pictures below not the best quality but any questions just ask.

I Probably forgot a step or two so I will edit below on this post if i remember anything. I hope its not a waste of anyones time and you get the same results.

 

[morgin]

Pic 1 set

 

[morgin]

Pic set 2

 

[morgin]

https://drive.google.com/drive/folders/15KLOp5fRKdu7IBpvEbadl-GsyYE3skxf?usp=drive_link

This is for the home theatre V4 driver hope ive set the permissions right

 

[musicreo]

The images show that you use the LAV filters to decode the true HD stream (already at this point it is only 7.1 and the atmos object part is ignored). The audio is sent to vb-cable. EQ-APO/ hesuvi is installed for vb-cable and process the audio with your brir. Vb-cable routes the audio to the TV (here you have only stereo). On the TV driver dolby home theater is installed and depending on your settings processes the audio again. That you like the additional pocessing is a coincidence and not related to atmos.

It is also not suprising to hear a plane above your head. The sound from the plane is probably recorded on the ground and hence contains the direction.

 

[morgin]

I understand what you’re saying and I don’t know what is working but the sounds are all over and natural at the correct distances and space. You feel the space or room. I’ll leave the post up if someone tries and it works then its all good. If not then it’s probably just perfect for me for some unknown reason.

 

[Davesrose]

The link to google drive isn't working....from what I can tell, Atmos isn't used if you're going through Vb-cable. Perhaps the driver for Dolby Atmos with the LG driver is adding a certain EQ that sounds better with the headphone virtualization you're using (HeSuVi is older and says it's 7.1 surround). I'll try seeing if I can find this Dolby Atmos driver for audio devices: I don't think it matters brand. For example, I first go through my receiver from my HTPC (so I'd need to setup the driver for it). I've got EQ-APO/HeSuVi, vb-cable, and MPC installed on my HTPC. I suppose if I want to switch from headphone or 7.1.4 speakers on my setup, I'll have it set to vb-cable or my Denon device. I usually don't have a need to watch movies via headphones, but it would be neat if there is good software for headphone 3D. But I also tend to use a streaming device since PCs still don't support Dolby Vision out, and a lot of 4K movies I have are DV.

 

[Davesrose]

Just another note as I'm trying to install things. Looks like the driver is Dolby Digital Home Theater 4V. I'm currently having some issues trying to install it, but there's a couple sources I've found. This first one has an audio driver you first install (which is currently hanging) https://forums.guru3d.com/threads/d...er-drivers-for-your-built-in-hd-audio.392085/ Another one that has a different installer (that I may try next) https://www.gizdev.com/install-dolby-home-theater-v4-windows-7-8-10/.

I don't think you really need the Dolby Access program: your screenshots show a 7.1 speaker system (which you can set in Windows settings). In the past when I've tried to look at my Atmos receiver device with it, it has shown 7.1.4 speakers. It also seems pretty clear that Home Theater 4V is not processing overhead effects. It intends to simulate 7.1 (so it may sound much more convincing to have things go from front, sides, to back of you). I'll try to get it working to give my impressions of the effect with my ears/headphones.