DD1+ WAV vs. MP3

[Taxed1]

I ran into this strange problem yesterday. I create my own test tones with Audacity after finding out some of the test tones we commonly use are not really 0 dB or -5. Anyways that’s another topic.

 

I noticed a weird problem while tuning this specific Pioneer head unit. I was able to max out the volume with no distortion when using a 0 dB .WAV file but if I switched to a 0 dB .mp3 there is distortion at max volume. I had to knock it down a few clicks to 37. So strange. I use a USB stick to set gains. My .mp3 tones are created with a bitrate of 320kpbs and a sample rate of 44100 hz. I’ve used these tones multiple times. 
 

Since this person I am setting the amp for usually uses Bluetooth and a usb stick full of .mp3 songs I decided to tune the amp using the .mp3 tone at a lower level without distortion which was volume 37. Has anyone ever seen this when using their DD1+? Could it just be a shitty Pioneer that .wav files are good up to max volume but not .mp3? I even tried some of the D’amore tones that are .wav files and saw the same problem. .wav tones are good up to volume 40, .mp3 only good up to 37??

[Joe X]

In the circumstances you are in I would use a scope to setup gains, the scope will be able to tell you what differences there are between the mp3 and wav as reproduced in that system.

[EricM9104]

mp3 files utilize compression to make the file smaller, whereas .wav is essentially a raw audio file with no compression, similar to flac audio files.