Should I Re-rip MP3s using batch ripper or use batch converter to adjust compression?

[BriGood]

When I initially ripped the CDs, I used the software’s “standard” MP3 setting (LAME encoder with variable bit rate (190KBs estimated) which upon closer inspection under the “advanced” button shows frequency=source, channels=auto, and quality=default).

Afterwards, when I perform a batch conversion (forcing 16 bits and 44.1KHz sampling) of the resultant MP3 files ripped with the original settings, I see an average 16% reduction in file size and no audible difference (to me) in recording quality. The waveforms in Audacity look identical. I have not yet figured out how to do a “diff” comparison of the alternate rips, but my guess is that the data inflation from oversampling is at least partially offset by compression of consecutively unchanged data elements.

So, given that the source material is CD quality (16 bit 44.1Khz) is it worthwhile to re-rip at the source rate or convert the resulting MP3s to the smaller file size resulting from 16 bit 44.1Khz?

Thanks for any advice.

[Spoon]

Re: Should I Re-rip MP3s using batch ripper or use batch converter to adjust compress

They are smaller because you ran the conversion again, and more audio quality was lost (as happens each time you convert to mp3).

[BriGood]

Re: Should I Re-rip MP3s using batch ripper or use batch converter to adjust compress

They are smaller because you ran the conversion again, and more audio quality was lost (as happens each time you convert to mp3).

Thank you for this advice, Spoon. Although I am familiar with some aspects of resampling and data compression, I am unfamiliar with the mechanics/rules of MP3 compression. I was under the mistaken assumption that higher frequency sampling would simply expand the source data and the re-sampling would result in repetition of unchanging data elements which would be compressed with a longer run-length multiplier, but apparently a little knowledge can be dangerous.

So when ripping CD source material into an MP3 derivative, in order to achieve an optimal balance between file size efficiency and faithful reproduction, how should dbpoweramp's ripping parameters be set (assuming the source material was digitally mastered at a 44.1KHz frequency and 16bit quantization)? As I recall, used dbpoweramp's 'Standard' setting (as opposed to 'Medium') on the software's sliding scale. Is this wrong?

Thanks.

[Spoon]

Re: Should I Re-rip MP3s using batch ripper or use batch converter to adjust compress

As source matches the source, so it is the same as selecting 44KHz.

[BriGood]

Re: Should I Re-rip MP3s using batch ripper or use batch converter to adjust compress

Got it. Thanks.