Yes I do have a capture card taking a direct LPCM feed from my PS4, and no your further attempt to claim its inaccuracy (which its not) don't show anything other than your massive confirmation bias.
I also downloaded and extracted the audio from your direct vs headphones videos and ran them through a DAW to take a look at any differences.
The only differences is that the headphones one is around 7.2db louder (on a zero peak db scale) and suffers from clipping and distortion, add 7.2db gain to the direct audio and ensure it doesn't clip and not only does it sound pretty much the same, it gets rid of a lot of the annoying distortion you get from a phone recording.
Just for fun I ran a THX set-up and calibration disc on my AV system (both via PS4 and dedicated Blu-Ray player. No issues at all with my set-up. Not that I am surprised, I've run AV systems for over 20 years and have no issue with regard to the set-up and calibration of them. It was re-calibrated a few months back anyway when I got a new sofa unit.
I would also like a source for your claim that decoding errors between 7.1 and 5.1 are the cause of the 'vacuum cleaner sounds'.
It also doesn't explain why such an error (if it even were the cause) doesn't affect other titles and why it persists across different listening devices.
Now I run a PS4 Pro out through a number of routes:
- via HDMI to either my AV receiver (a Sony DA2400ES) to a set of Monitor Audio Radius speakers and sub
- via HDMi to an elgato HD60 capture card (and set to mid 250kbps - bit rate that is more than acceptable - for comparison your 'headphone' capture is 132kbps).
- via optical to a set of Turtle Beach 520p 7.1 headphones.
They all give the same basic characteristics in terms of audio, now what exactly is it that you are using that makes all three of these routes so flawed?
So what audio format are they using that is causing so many issues for so many?
Oh and I'm going to want a source for it as well.
You are mixing up frequence of sound with the volume of sound, they are not the same.
Now in terms of low frequency sound (to the degree that you feel it) GTS is not bad at all.
In terms of feedback I get from my tactile rig GTS is on a par with Driveclub and Assetto Corsa in this regard, its well below Project Cars and Dirt Rally, but above F1 2016, Seb Loeb Rally Evo and WRC6.
However its not anything 'special' in that regard.
Note that I am talking about true LFE here, 10 to 300hz, with anything below 32 being lower than the range of human hearing.
Now I have to be honest and expand my reply to not just the content of your post, but to the behavior pattern it typifies.
The audio in the GTS Beta is an improvement on the audio from past titles, with for example the new Porsche's sounding more than acceptable for me. Some cars still sound poor, but its also a beta. Now while I would ideally love GTS to have genre leading audio, the hard fact is that it doesn't. That alone doesn't make it a bad title.
Project Cars has had incorrect samples used for at least one car (that they did then patch), Seb Loeb Rally Evo has the worst sound of any sim I have ever played, Assetto Corsa is still hit and miss, with some sounding great and others still needing a lot of work.
Do you see how easy it was for me to honestly and openly accept that other titles I like have issues with either elements of the audio or in the case of Seb Loeb, everything about the audio.
What you are doing however is a trait that unfortunately seems (from my experience) to define an uncomfortably high number of GT fans, the inability to accept that flaw and issues may well exist within your 'chosen' series.
Its quite frankly absurd, as it leads to more and more outlandish claims to try and support your own internal bias. No one is going to judge you for being OK with the sounds as they are in GTS, but to try and claim that no issue exists and that the problem is simply with how everyone else is listening to it is just 'odd'.
I'm listening to the GTS audio through three different route (four if you include tactile - which you sound - its still part of the audio output), all of which total around £2,500 worth of kit, a £1k of which was for a single bit of Sony kit. Yet according to you the reason why I have issue with some elements of GTS' audio is because all of it is either not set-up correctly, broken or not compatible.
Its an insane argument to even start to make, but you seem to want to make it.
So as I have already said, I've shown you mine, lets see yours. What do we need to have to be able to experience what you are?