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Converting from .m4a to .mp3.-any sound quality loss as long as KBPS is the same?

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Hey guys,
Considering switching from iPhone to Android. When using Google Play, you can upload your current music Google Music Manager, and download it to your new phone if you like..
Easy enough. All of my music on my iPhone is purchased from iTunes and is in .m4a format. Google music manager converts it to .mp3 format. I messed around with it a little, and for example, a song that is uploaded that originally had 262 KBPS in .m4a format now 'has' 256 KBPS in .mp3 format, so virtually the same. 
So my question is, should the sound quality be the same as long as the KBPS is the same (or very close), or could there be other factors that could possibly reduce the sound quality after converting to .mp3?
Thanks
Travis

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Bit-rate is just one aspect of the audio-codec. Are you planning to stream the MP3 to regular stereo system or just use it on the phone? Here is an example, where bit-rate is the same, but one is Apple Loseless, the other is a MP3 of the same song. For example, see the differences. If I play both of them through a BillD C1/M500t MkII, I can tell the difference between the two versions. I use an Airport Express Gen 2 to stream from iTunes.
 
20170327152243301.png 
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Stream rate, compression and sample rate are all different things.
 
Disclaimer: There will always be subjective objections.
 
 
Changing the streaming rate will not effect the quality all that much. Anything above 192kbs is absolutely impercievable.
 
Compression is a different matter. Some algorithms are better than others. Unfortunately, mp3 is not very good. But the good news is, neither is m4a - so if the latter doesn't bother you then it's unlikely mp3 will either.
 
 
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Hey guys,
 
Considering switching from iPhone to Android. When using Google Play, you can upload your current music Google Music Manager, and download it to your new phone if you like..
 
Easy enough. All of my music on my iPhone is purchased from iTunes and is in .m4a format. Google music manager converts it to .mp3 format. I messed around with it a little, and for example, a song that is uploaded that originally had 262 KBPS in .m4a format now 'has' 256 KBPS in .mp3 format, so virtually the same. 
 
So my question is, should the sound quality be the same as long as the KBPS is the same (or very close), or could there be other factors that could possibly reduce the sound quality after converting to .mp3?
 
Thanks
Travis
 
"So my question is, should the sound quality be the same as long as the KBPS is the same (or very close), or could there be other factors that could possibly reduce the sound quality after converting to .mp3?"

 

SHORT ANSWER -- In your case, the sound quality will be very close.  Convert my friend.
 
 

Image result for convert m4a to mp3

 
 
 
 
If you want more of an explanation, read on. 
 
 
 
 
Travis, M4a files can be lossless, (and thus larger files) which means very little compression and preserving much of the original song recording.
 
OR
 
in your case, lossy M4a files--which means they have been compressed to make the files smaller by using coding algorithm's that take out much of the information that is believed to be inconsequential to the listener.  
 
Since you downloaded these files from Itunes, they are in the lossy AAC (advanced audio coding) format.
 
 
 
In a perfect world, we would want our cake (lossless) for the best sound quality AND have unlimited hard drive space to contain these much larger files.   
 
 
MP3 is also a lossy (highly compressed) format.  It is a more accepted standard (although M4a is catching up) but just slightly inferior in sound quality.  Most folks would probably never hear the difference.  However, us audiophile nuts just might Big Grin
 
This difference becomes almost negligible at bit rates above 128k.  Since you are converting 262k lossy M4a files to lossy 256k MP3 files, you most likely will not notice much difference.
 
A quote from "How stuff compares":
 
 
"M4A audio with Apple Lossless compression delivers the best sound quality since none of the original signal is lost.
 
For M4A audio encoded with AAC lossy compression, blind tests indicate that it provides greater sound quality and transparency than MP3 files coded at the same bit rate, particularly for bit rates at or below 128 Kbps. However, as bit rate increases and more of the original sound signal is preserved, the relative advantage of AAC over MP3 becomes less obvious."
 
 
Thus...convert away.
 
One other note, if you do own Lossless files (FLAC or ALAC, Wav, etc.), you can always convert to lossy and lose sound quality... but once it's converted to say, lossy MP3....it's gone.  You cannot take lossy and hope to convert to lossless adding back all the original coding to obtain the original file.
 
Here is the link if you desire more reading:    Cheers Beer!
 
 

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It hasn't been explained that m4a is not an audio file format. It is a container that can contain either a lossy or lossless file. The conversion to mp3 from an m4a file very well might reduce your file to a lossy format. Will you hear it? I dunno.
 
 
But since MPEG-4 Part 14 is a container format, MPEG-4 files may contain any number of audio, video, and even subtitle streams, making it impossible to determine the type of streams in an MPEG-4 file based on its filename extension alone. In response, Apple Inc. started using and popularizing the .m4a filename extension, which is used for MP4 containers with audio data in the lossy Advanced Audio Coding (AAC) or its own Apple Lossless (ALAC) formats.  
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It hasn't been explained that m4a is not an audio file format. It is a container that can contain either a lossy or lossless file. The conversion to mp3 from an m4a file very well might reduce your file to a lossy format. Will you hear it? I dunno.
 
 
But since MPEG-4 Part 14 is a container format, MPEG-4 files may contain any number of audio, video, and even subtitle streams, making it impossible to determine the type of streams in an MPEG-4 file based on its filename extension alone. In response, Apple Inc. started using and popularizing the .m4a filename extension, which is used for MP4 containers with audio data in the lossy Advanced Audio Coding (AAC) or its own Apple Lossless (ALAC) formats.  

 

1. Actually, if you click on the article link, the very first paragraph explains the Mpeg4 container concept. (I did not want to add words like container & Mpeg4 in the body explanation as these terms can tend to confuse folks) :
 
"M4A, short for MPEG 4 Audio, refers to a compressed audio file in the MPEG-4 container format.
Although the only official filename extension defined by the MPEG-4 standard is .mp4, MPEG-4 files that only contain audio typically have a file extension of ".m4a". The .mp4 extension is used for MPEG-4 files containing both audio and video. Songs that include copyright protection have an .m4p extension.
 
Apple Inc. popularized the .m4a filename extension, which is used in iTunes for songs encoded using either the lossy Advanced Audio Coding (AAC) or the Apple Lossless (ALE, ALAC) codec. M4A audio files with Apple Lossless compression are generally about half the size of the original file whereas those with AAC lossy compression can be as small as 1/10 the size of the original file. Note that AAC was designed to be the successor to MP3"
 

2. The 2 different M4a filename encoding "formats" (lossless & lossy) were explained above.

 
3. Trav is converting higher bit rate M4a lossy (his Itune downloads) to MP3 lossy files. (not lossless to lossy). Sound difference will be negligible as noted above. Phones

 

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look up trans-coding errors; there is loss.  Back when I was a 'man who isn't there' we proved that converting from NITF to TFRD and back (Uncle Sam's version (in a way) of TIFF and JPEG) again accounted for a 0.5 NIIRS loss in integrity of the original file.

 

Considering that it costs several hundred million dollars to achieve a 0.5 NIIRS increse in resolution, we were able to demonstrate that analysts were needlessly throwing away data.

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9 minutes ago, RichP714 said:

look up trans-coding errors; there is loss.  Back when I was a 'man who isn't there' we proved that converting from NITF to TFRD and back (Uncle Sam's version (in a way) of TIFF and JPEG) again accounted for a 0.5 NIIRS loss in integrity of the original file.

 

Considering that it costs several hundred million dollars to achieve a 0.5 NIIRS increse in resolution, we were able to demonstrate that analysts were needlessly throwing away data.

 

Right, there has to be...compression loss contributes to digital generation loss (one short cut is passed on to another, which can create another short cut). And although 'lossless' is used as a code word (har) it's still compression, which means it will contain artifacts. Maybe not perceivable by 99% of the population, but hey, if a company can use 'Miracle Whip' for rotten eggs then why not Lossless Audio for 1's and 0's. :D

 

I wonder how many transcodings from one format to another and back again can cause enough loss it approaches a static, and maybe unrecognizable data?

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