0

I have several sound effects in ogg format. I have to export them in mp3. I oppened each of them in Audacity and used export functionality to achieve my goal. But when I played the sounds in mp3 format, they had poor quality, like they have some hidden buzzing.

How can I improve, or should I use other tools to export?

3

This question is a bit out of context on a sound design q&a site, but easy to answer. Whenever you re-encode an already encoded soundfile (mp3>export to mp3) you lose more 'sound' information. Look up 'lossy' and 'lossless encoding' on wikipedia and you'll understand it better.

Oh and in general it's easier for us to answer if you include more details. In this case: what bitrate did the original ogg file have? And what bitrate did you choose for the mp3 file?

  • I am recording on my Nexus 7. It has several options, like ogg, wav, flac and mp4. Currenty ogg format, bitrate is 64kbps, sample rate 44100hz, stereo two channel. I was exporting to mp3 also in 44100 hz, constant bitrate, stereo. Should I switch to wav and then export the recordings to mp3 and ogg? Will the results be better? – Vlad Mar 21 '14 at 14:26
  • Yes, if you can, do so. By the way 64kbps is very low quality, comparable to phoneline quality. Did you not here this earlier on? Do you monitor your recordings? – Arnoud Traa Mar 21 '14 at 15:14
  • "Did you not here this earlier on? " Here should have been hear of course. – Arnoud Traa Mar 21 '14 at 21:49
  • Why the output is so quiet? How do I record much louder voice? Or should I just speak louder? I am recording in wav format. And the exported mp3 and ogg are decent quality. – Vlad Mar 24 '14 at 10:35
  • 1
    I don't know Vlad. perhaps you should invest in recording workshop or buy a handheld recorder. – Arnoud Traa Mar 24 '14 at 10:51
0

64kbps at 44100Hz stereo is pretty lousy, more so with MP3 than with OGG in my experience. So if you want your recording not to deteriorate further, you should likely use at least double of that when going MP3.

That generally is a problem: the highest compression ratio dictates the quality of the result, and if the deterioration should not significantly increase, all other lossy compression passes need to have decidedly higher bitrates.

So if your recording is with 64kbps and already has the lowest quality you can really justify, a reencoding with a different algorithm will likely have to happen with 192kbps in order to yield results close to the original 64kbps recording. Not satisfactory.

So as a rule: highest compression/lowest bitrate is the last step before distribution, or your distribution bitrates will be significantly higher than your distribution quality.

Even then, multiple recompression, in particular with different compression algorithms and consequently different compression artifacts, is a bad idea anyway.

That does not mean that you need to record with wav: flac is lossless compression, so the results are indistinguishable from a wav recording and the file size still is about a third.

That's the best format to choose when you are going to export to different lossy compression formats and/or going to do additional editing.

With regard to the loudness of wav: that's likely the original loudness. Lossy compression formats tend to contain the information necessary for normalizing the loudness (I think flac does as well), so your replay is probably adapted to that normalization. However, noise is normalized along with the rest, so you are better off if your wav file does not sound all too quiet in comparison to the other formats.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.