Puzzled by 4.7 speakers being way louder than 5.5. Anyone?

So I stumbled upon this (Russian) video today, in which the reviewer compares the 4.7 and 5.5 speakers. To my surprise the 4.7 speakers sound way louder and possibly better. To me this doesn't make sense and leads me to believe something isn't right with the 5.5.

Did any of you compare both the devices speakers and what were the results?

The video: (speech can be translated into English)

https://www.youtube.com/watch?v=AKLex3CNATM&t=2m35s

Help with louder sound

Hi,

Using 5.1.1 546 and I want louder sound without having to flash one of the various mods. Does anyone have a mixer_paths.xml that has stereo ringtone and notifications and boosted headphone and speaker volumes.

Used to have one for 5.0 that I loved but can not find it.

Thanks in advance