Distortion Problem on Sansa

[Vortex]

Hi everyone,

I recently noticed that some sounds, especially sharp "s" or "z" sounds, where somehow distorted on my Sansa. The files play fine on my PC, without distortion.

I have, however, found a workaround for the problem: Enable the Equalizer and set the Precut to -5dB but leave all other settings untouched (i.e. leave the graphical EQ at the "flat" default setting). The distortion then disappears.

It doesn't matter what the volume is set to (I usually listen to music at -20 to -30 dB), without the "precut trick" the distortion always occurs.

Can someone confirm this on their device?

[cpchan]

How recent is your Rockbox?

Charles

[Vortex]

I am using your latest build, so it's fairly recent.

This problem also exists in the official SVN version.

[X86]

distortion in sansa? huh? I've never noticed about that,for me thats weird,sansa now works almost flawlessly

[cpchan]

Yes, it is there. I guess you are a lot more sensitive to this particular artifact then most of us.

Charles

[X86]

the sansa has a great sound,its very good with rockbox,but if you want to go back to the original sansa en you dont have a sansa rhapsody I would recommend to install the rhapsody firmware,it sounds very very good,it plays real audio files,wma files and mp3 files,but the real audio sounds better and the codec removes glitches in the audio files.

[cpchan]

but the real audio sounds better and the codec removes glitches in the audio files.

Wow, first time I have ever heard of anyone putting "Real Audio" and good quality in the same sentence.

Charles

[Vortex]

Wow, first time I have ever heard of anyone putting "Real Audio" and good quality in the same sentence.

It's also the first time I heard that.

Anyways, I'm not planning on going back to the original firmware. Like you have said, the distortion is barely noticeable and there is an easy workaround, so basically it isn't a problem at all.

[Llorean]

Do your files actually peak over 0dB internally? Try replaygain scanning on them, and seeing what level is necessary for clip prevention.

[linuxstb]

Wow, first time I have ever heard of anyone putting "Real Audio" and good quality in the same sentence.

"Real Audio" is just a container format and can contain one of many codecs, ranging in quality from very poor to lossless:

http://en.wikipedia.org/wiki/RealAudio#Codecs

I've downloaded some very nice sounding ATRAC-encoded realaudio concert webcasts in the past.

[X86]

the real audio codec is like wma for microsoft,the real audio codec is like an improvement of the wma codec,I had my sound library in dap as wma files,but now I converted my sansa into a rhapsody one and I converted all my files to real audio,also I used rhapsody music management and it transfer the files really fast  

[cpchan]

"Real Audio" is just a container format and can contain one of many codecs, ranging in quality from very poor to lossless:

Ah, thanks, I didn't know RA is just a container format. I had bad experiences with some of their earlier stuff. Now this looks interesting for lossy:

raac: MPEG-4 LC-AAC (RealAudio 9)
racp: MPEG-4 HE-AAC (RealAudio 10)

Charles

[cpchan]

Do your files actually peak over 0dB internally? Try replaygain scanning on them, and seeing what level is necessary for clip prevention.

I do have replaygain values in all my files (Vorbis encoded with the latest AoTUV). I have replaygain turned on and "prevent clipping" turn on, but I do hear the slight distortion the OP is referring to. However, I am not that sensitive to that artifact, so it is acceptable to me.

Charles
   

[Llorean]

Well the thing is, if we're producing distorted output, then 1) It should show up on RMAA tests, and 2) We need to fix it. Can you provide more information?

[X86]

distortion on sansa?,I dont feel it,and about real audio files,those are better and wma too,but real audio codec is like an improvement to the wma codec,but in another way as container,if you use a 128kbps encoded wma the equivalent to that file in wma is the real audio at 160kbps,almost same size.What about distortion,may someone explain me on what consists that?,I know what is distortion,but what is the sound.