[OnePlus 6T  Guides, News, & Discussion] Extreme_Ninja2099:
This is a guide to install mods for OP6/6T that achieve a dual speaker setup that's like the device has stereo-like speakers. I have helped many OP6 and 6T users to achieve this.

Custom ROMs that work with this mod (TESTED):

Stock Oxygen OS

AOSP Extended

ArrowOS (OP6 only)

CrDroid

Evolution X

KangOS

Pixel Experience

PixenOS (EOL)

SyberiaOS

Disclaimer:

*I am not responsible for bricked devices, damage to your device*

I am here to post my method for anyone who is interested. I have tested this myself and helped others to do this.

Issues:

There are issues with the SElinux manager installation and setting SElinux to permissive in my experience. There are alternatives and modules that can be trusted. I have provided links that I have tested and the best module that sets SElinux is the SElinux permissive module. There are SElinux manager modules, but they don't consistently work or install. Like V1.0 doesn't work, try V1.0.5 or vice versa.

IMPORTANT:

Old:

Setting SElinux can have security issues noted by @topjohnwu, so install this mod at your own risk.

Unfortunately, I have not found any method that installs Dolby atmos with SElinux Enforcing and all mods from reiryuki don't work on 6T (OOS 10.3.8). You can try yourself, but backup beforehand as it causes bootloop.

Any other method I found re-uses repey6 and installs it wrong (without setting SElinux)

The alternative module I have found is Viper4Android and can be installed with SElinux Enforcing

New:

Dolby Digital Plus now has released a new version that works with SElinux Enforcing.

Viper4Android is outdated sadly. But There' Viper4Android RePackaged

Methods:

The method works on OOS work on Custom ROMs as well

Download the files required from the links provided and choose Dolby or Viper

Install dual speaker mod and reboot

The OP6 will have many versions that don't install after rebooting so repeat this step until you've installed a version successfully V10 works in my experience. For the Oneplus 6T V3 works.

3. Test it to see if it works and check if it has installed in magisk modules

Dolby Digital Plus Method:

OLD:

Install Dolby digital plus and reboot.

Test it to see if it works and check if it has installed in magisk modules

Install SELinux permissive to set SELinux to permissive and reboot. You need to set SELinux to permissive to make the Dolby mod work properly.

Go into magisk modules to check if SELinux permissive module is installed. If it wasn't installed try another module like SElinux manager 1.0 or 1.0.5 if one of them didn't work, try 1.0 vice versa or the SElinux changer APK. Reboot and check in magisk modules again.

Install audio modification library, reboot, and done.

NEW:

Install Dolby digital plus and reboot.

Test it to see if it works and check if it has installed in magisk modules

Install audio modification library, reboot, and done.

Fix for Dolby:

The next issue is with Dolby digital plus. If the speakers sound quieter than normal and the app stopped working...

Go into settings, app settings, find Dolby app.

Go into permissions. Turn storage on and off.

Try it again and the issue should be fixed.

Enjoy :)

There is an alternative to Dolby atmos and it is Viper4Android where SElinux is enforcing as well

Viper4Android Method:

OLD:

With the old V4A module

Once you got dual speaker mod installed

Install Audio Modification Library, reboot and disable it

Install the viper4Android module.

If a new version of viper4Android module is available, install that

Reboot.

Open the app and grant root

Install drivers in the app and it will reboot automatically

If u want to have DDC, kernel and preset files look at the

DDC, kernel and preset files manual method

below

NEW:

With the new V4A Repackaged module

Once you got dual speaker mod installed

Install Audio Modification Library, reboot and disable it

Download and extract the guide setup or the other .zip file attached below on your device

Install the viper4Android Repackaged module.

Reboot

Open the app and grant root

DISCLAIMER: On custom ROMs or certain devices, the drivers are installed, but NOT working properly after reboot. Just continue the method and comment if there are issues once u have finished the method.

DDC, kernel and preset files manual method

Download and extract all the V4A files or just the file for this guide setup I attached below. You need the DDC, Kernel and Preset folders. Copy all the folders!

In Internal Storage: Copy and paste the folders into (Android -> data -> com.pittvandewitt.viperfx -> files), this would replace each folder.

Now go into magisk manager, go into modules and enable AML. Reboot

Now make sure V4A driver is running (read Notes) and go into convolver -> impulse response. Choose any kernel, and done. OR choose the preset for that and done. If you have issues, make sure legacy mode is on in settings but it is on by default.

Choose at your heart's desire if you downloaded all the V4A kernels.

I personally use Dolby Digital Plus - Centre kernel

Done, also post the settings or kernels and your thoughts. :)

I also attached a screenshot of my configuration

Note: Viper4Android sometimes doesn't turn on properly. So, play music and open the app to check the driver. The Driver status if it's working (NEON enable: yes, Enabled: yes, Status: Normal) and turn on the master limiter to see if there's an effect. This should give you an indication if V4A is working or not

I have attached DDC files below and you do the same thing with kernel files, but they are used for headphones.

You can try and add the preset (profiles). BUT U SHOULD HAVE ALL THE DDC AND KERNEL FILES FOR THE PRESETS TO WORK PROPERLY

Choose the specific presets u want

Transfer them into Android -> data -> com.pittvandewitt.viperfx -> files -> presets

Transfer the V4A.zip in internal storage

Reflash the V4A.zip again and reboot

Install the V4A driver again and reboot

V4A driver should be working, check the presets and it should be there

Enjoy having your presets

Fix for V4A:

There has been noted issues during the installation with V4A. If you experienced a bootloop after installing V4A in magisk...

Boot into TWRP, -> advanced -> file manager -> data/abd/magisk/modules and delete the V4A folder.

Reboot to system, install the module in magisk again and reboot. It should install.

Another issue was that V4A driver is installed properly, but there are no enhancements to the sound. To fix this, go into settings and turn on legacy mode. This should make the effect stay on, even though this should be on anyways.

New Update V4A

Also, for new users if u connect your earphones like via headphone jack, USB-C or Bluetooth. You can tweak those as well than just your SPEAKERS! BUT some earphones can be damaged as well, so tweak at your own risk.

After much tweaking myself. I think I have made my speakers much better and achieved almost stereo speakers for my 6T.

I have attached a screenshot to the thread at the bottom. I have attached a screenshot for my headphones too!

I have added the individual settings as well. If u want to tweak them just press the text and it should expand.

The toggles I have on are for my speakers:

Master Limiter

Playback gain Control: Strength: 2, Maximum gain: 3X, Output threshold: -1.9dB

Convolver: Dolby Digital Plus - Centre, Cross Channel 100%

Speaker optimization

I have also tweaked my Bluetooth earphones as well with a DDC and the screenshot is attached below. I recommend Dolby headphone Live, but that's up to you.

U can add files in the DDC folders in the Android folder, but reboot and then tweak to see the difference. U CAN RISK DAMAGING IF U TWEAK TOO MUCH

You have completed the guide and can now experience dual/stereo-like speakers on your OP6/6T.

Enjoy :)

If anyone has any issues with this guide. Post a message and I'll get back to you :)

Links:

Modules required

Oneplus 6T dual speaker module Link

OnePlus 6 dual speaker module V10 Link

Download Dolby + SElinux files if u want Dolby Digital Plus installed

Dolby Digital Plus module Link

SElinux modules are no longer needed for Dolby Digital Plus

SElinux Permissive module Link

SElinux Manager V1.0 Link

SElinux Manager V1.0.5 Link

Audio Modification Library Link

Download Viper4Android and one of the preset files if u want Viper4Android installed

Viper4Android Module (OLD) Link

Viper4Android Repackaged Module (NEW) Link

All Viper4Android preset files Link

Viper4Android files for this guide is attached below

All DDC, Kernel, and Presets in one zip is attached below

Threads where the modules are from

OnePlus 6T dual speaker thread Here

Oneplus 6 dual speaker thread Here

Dolby Digital Plus thread Here

SELinux Manager thread Here

SELinux Permissive thread Here

Audio Modification Library Thread Here

Credits:

@voske15 for his Dolby Digital plus module

@repey6 for his thread and guide to install the Dolby Digital Plus module (9.0 - 11.0)

@acervenky for his module to allow dual speakers for the OnePlus 6 and OnePlus 6T

@evdenis for the SElinux permissive module

@Jman420 for his SElinux manager V1.0 and V1.0.5 module

@Zackptg5 for his Audio Modification Library and Viper4Android module

@Vimal Vinz for the V4A DDC + Kernel + profiles