[General Topics] Elements1984:
I have some good news for you :)

I took a look at your xml file and I wanted to know what would be the maximum value I could set to certain various, so I googled and I found a thread which already implemented these changes in a mod with various boost levels. The files in the thread are flashable zips (twrp or cwm or any other will do). Alternatively, you can unzip the zip of your choice and go inside the system folder then etc and copy the xml file from there and replace manually the one in your device's system/etc folder by overwriting it.

Here is the link to the mods: http://xdaforums.com/showthread.php?t=2729652

As I already mentioned before, sometimes mods will not work if you happen to have a different android version or a different device, so what I did is to open the xml you provided and open the xml from this mod side by side, I compared them line by line to make sure that all the lines from the mod are the same as the ones from your file (a missing or different line would lead to a possible crash or missing feature or error messages due to a bad linking), I was pleased to see that everything from this mod is 100% the same as in your file, it's just the values that are increased comparing to your file (since this is a sound boost mod). So I can assure you that this mod will work on your phone, just make sure to temporarily disable viper4android to avoid any possible conflict, try the different boost levels until you find the one that suits you most, then you can try to enable viper4android again in order to equalize your sound, it shouldn't cause any conflict in my opinion.

As to what I think you should choose, from what you mentioned in your last post I would say the V1 lite or the V4 Lite would be perfect for your needs.

Don't hesitate to ask me if there is anything else I can help you with ;) And please tell me if it worked for you :)

PS: make sure you grab the KitKat version of the mod, not the lollipop, as I think you're still running KitKat and that's the version of the XML I checked ;)

Note: It looks like Samsung engineers are very smart in the way they set their default sound values, I say this because it looks like the HPHR and HPHR levels are already set to their maximum (Most other manufacturers have these lowered, such as what I found out in my Sony Z1). So what they did is setting the amplifier to the maximum value and reduce the gain value well below the norms (this is the RX value) in order to avoid distortion and/or possibly to be in conformity to the international laws that forces manufacturers to set a volume limit to avoid hear damage. So basically, all that needs to be done is to increase the gain through the RX values knowing that there is a point where going beyond will affect the sound quality. I think V1 lite and V4 lite will be under or equal to the right balance between loudness without losing quality. V2 medium may be equal or over the balance level, the increase in loudness will be big but the decrease in sound quality might not be noticeable to the average user, so that's possibly still a good value to consider if V1 lite was not loud enough for you, although I don't recommend it. V3 is a big NO for me, I guess you already know why, lol