How To Setup Viper4Android For The Best Audio Experience Possible

I recently changed my Cyanogenmod based rom to an AOSP one. One featured I got very used to on the Cyanogenmod based rom was the AudioFX since it greatly enhanced the listening experience on my somewhat bad earphones. I looked for alternatives including a flashable zip for AudioFX but it didn't sound the way it sounded on the Cyanogenmod rom. Changing my rom has let me to one the best mod discoveries on my Android phone.

Viper4Android

Viper is a great third party mod which makes your terrible sounding earphone/headphones into great sounding ones. It lets you customize almost every aspect of the sound that's leaving your phone. It wasn't as good as AudioFX initially but after extensive research I've got it sound much better than AudioFX. The stock equalizer doesn't even compare to Viper so we won't be talking about it here. Viper has made my phone's sound the best I've heard in a long long time. So what are we waiting for, lets get right into the setup. Before proceeding you need to make sure that you're rooted. 

Setup

You will need the following to get Viper working on your phone: 

• Viper4Android (don't be turned off after seeing the Chinese, the app itself is in English).
• A file explorer of your choice, I suggest using ES.
• Busybox.
• IRS Impulse Response Sample files (most important part of the setup). You can find more of these in the official Viper XDA thread. 

Installation Order

• Firstly, download a file explorer if you don't have one already. 
• Next, install Viper from the Play Store link I provided (no need to open it yet). 
• Now download the IRS files zip and extract it to the root of your device. The extracted folder, i.e. Viper4Android should be there along with your other root folders (DCIM, Downloads, Music, etc).
• Now download Busybox and open it up to install busybox on your phone.

The initial setup is now complete. We will now move into setting up Viper itself. 

Viper Driver Setup

• Open up Viper4Android. The app will ask you to install the sound driver. Chose super quality for the best sound. 
• After the driver has finished installing, reboot your phone. 

Viper Settings

The settings that I will be showing you are the way I like my phone to sound. These are good for most of the people but for the audiophiles it's better to test each and every single option one by one to make the audio truly yours. Open the app and tap the three dots in the top right to open the drop down settings menu. Select UI setting and then choose “Expert”. Now make sure you're in the headset section of the app. Here we will be changing the settings that make the most difference to the audio output. 

• First of all, Enable "V4A-FX". If for some reason, you have changed the settings but you don't hear a difference tap "Force Enable V4A". Put on some earphones/headphones and play some music to hear the results in real time. 
• Next we will enable "Spectrun Extension". Set the strenght to 0.5.
• Now we will enable the "Convolver". This is the most important part of settings since it will use the IRS files we downloaded earlier. Tap "Impulse Response" and select "Dolby Pro Logic 1.irs". Set "Cross Channel" to 80 percent. 
• Now scroll all the way down to Fidelty Controll and tap "Enable ViPER Bass" to enable it. Set "Select Bass Mode" to Natural Bass. Set "Set Bass Frequency" to 100 Hz and set "Select Bass Boost" to 17.0 dB. These settings are optional just like the surround ones. Since I like Bass I've used the settings. 
• Now enable "ViPER Clarity", set the mode to XHifi and "Select Clarity" to 14.8 dB.
• The last settings Master Gain is also important. Using the "Output Gain" you can increase the volume output or decrease it if you don't like the output to be very loud. I've set mine to 6.0 dB since I like the volume increase. 

If you don't hear the sound difference in some music players such as Spotify, then tap the three dots on the top right and set "FX Compatible Mode" to Compatible.

Source: Reddit