xperia z2 hi-res audio

[SIQOIA]

i have noticed when playing hi-res files through the usb to my amplifier ,they are much quieter than my mp3s, even if i put normaliser on.
if i play the files through headphone jack i assume they are converted because they sound the same.
the files are 24/96 flac downloaded from multiple sites.
i was told by a friend that volume has nothing to do with bit depth or sample rate, so the volume difference must have something to do with a conversion that is going on.
this issue also happens over bluetooth in my car.

soooo.... my questions are:

1. why does the problem not happen when converted for the headphone jack?
2. what is causing the volume drop?
3. is there a difference between using an external dac or the one in your amplifier? this would also be an external dac?..am i wrong. my understanding is no.
4. how do i get these files to play properly on my home system..i am really excited to hear them.

also my set up is mhl to amplifier from my xperia z2 which offers usb hi-res output.
but i do believe that the problem has nothing to do with the amplifier because the problem persists when over bluetooth in my car...so i feel its something the xperia is doing.

and "no" i am not expecting the car to play hi-res through bluetooth, i am merely pointing out that the problem may be the same thing.

 

[The_Lhc]

Hi-res files typically sound "better" because they use a master with a much greater dynamic range than CD or mp3, this means the difference between the loudest and quietest parts is greater than what most people are used to.

It's not an issue, this is basically what you're paying the extra money for. The answer is simple: turn the volume up.

If you don't like that answer, there's an equally simple solution: stop buying hi-res audio and get the CD instead.

 

[fr0g]

I think LHC is almost on the mark.

It "sounds" like the HD files are audiophile recordings. If you do a spectrum analysis of them you'll find they are a lot quieter. Why they should work through the headphone jack I have no idea.

You can convert them yourself if you like.

The program you can use is "Audacity", it's free.

If you open the file, click on "Effect" and then "Amplify" then accept the defaults (maximum peak 0 dB, and not allow clipping)

Then simply save the resultant file. It should sound the same, but louder.

The following 2 images show what I mean...

This is a decent quality recording with peaks way lower than 0.

and after doing the amplify..

I have to add, HD audio is pointless other than the possibility you're getting a better recording. So it's also safe to resample back to CD quality, or even 320 Kbps MP3... It will sound just as good.