Optimal bit-rate for mp3

tradetime

Hi, would be interested if anyone who listens to music a lot or music file orientated / knowledgeable could tell me what the optimal size bit-rate would be for mp3 files.
Not sure if that makes sense, what I want to know I suppose, is how low a bit-rate can I go before sound quality suffers. trying to find a trade off between sound quality and file size.

Marty_J

Everyone hears differently, so no one can answer that but you. Try converting a piece of music you know well at different bit rates, and see what the lowest bitrate you find acceptable is.

I think 192 kbps would be good enough for most people, but it depends what you're listening to, and what you're listening to it on. Anything below 128 kbps will almost certainly suffer sound-wise, unless it's a spoken podcast or an audiobook or something.

Try it out for yourself and see.

tradetime

Thanx for that response Marty, am currently listening to 190 kbps and it sounds fine.am also listening to 128 kbps, and it sounds fine too, could be that I'm tone deaf
Am mainly listening to it on a walkman mp3 player, music files

Marty_J

I wouldn't worry, most people can't tell the difference.

If you know what compression artefacts sound like, it's much easier to tell, but most people don't know what they're listening for. Listening is a skill just like anything else.

192 kbps seems like a good compromise between size and quality.

BexTech

When using MP3 I usually aim no lower than 192kbps for MP3, but will really want 320kbps when using CBR. Though prefer VBR set at 32 - 320kbps.

Normally I use Flac when storing tracks on my HDD.

tradetime

Marty_J wrote: »

I wouldn't worry, most people can't tell the difference.

If you know what compression artefacts sound like, it's much easier to tell, but most people don't know what they're listening for. Listening is a skill just like anything else.

Lol, I'd be most people then, 192 and 128 sound exactly alike to me so that's good enough thanx.

Marty_J wrote: »

192 kbps seems like a good compromise between size and quality.

Sounds good.

tomstickland

The optimal bit rate is the one that gives a minmum data spacing of less than half the highest frequency a human ear can detect.
Mp3 and mp4 technology works by converting the sampled waveform into an alternative mathematical format using Fourier transforms. This essentially breaks tha data down into various wavelengths that are multiples of the time window size. All sorts of compensation and filtering is used along with compression.
So, after all that, I'd have no idea, other than the higher the better.

Mp4/AAC (advanced audio coding) is a significant step up from mp3 according to what I read on Wikipedia. My experience is that mp3 sounds a lot worse than CDs. It generally requires 1/10th of the storage space of a CD file.

tradetime

BexTech wrote: »

When using MP3 I usually aim no lower than 192kbps for MP3, but will really want 320kbps when using CBR. Though prefer VBR set at 32 - 320kbps..

Thanx for the reply, afraid your over my head here, had to look up VBR and CBR, and still not sure what CBR is

BexTech wrote: »

Normally I use Flac when storing tracks on my HDD.

Ok found that one as well, don't think my walkman would support that encoding.

tradetime

tomstickland wrote: »

The optimal bit rate is the one that gives a minmum data spacing of less than half the highest frequency a human ear can detect.
Mp3 and mp4 technology works by converting the sampled waveform into an alternative mathematical format using Fourier transforms. This essentially breaks tha data down into various wavelengths that are multiples of the time window size. All sorts of compensation and filtering is used along with compression.
So, after all that, I'd have no idea, other than the higher the better.

Mp4/AAC (advanced audio coding) is a significant step up from mp3 according to what I read on Wikipedia. My experience is that mp3 sounds a lot worse than CDs. It generally requires 1/10th of the storage space of a CD file.

Ok, personally I don't really notice any difference between mp3 and cd, though in all fairness, I have not listened to a cd on anything other than computer speakers fo so long, and they would not do it justice.
On the bitrate, I have ripped at both 128 and 320, and if I am honest, I can't really tell the difference.

BexTech

tradetime wrote: »

Thanx for the reply, afraid your over my head here, had to look up VBR and CBR, and still not sure what CBR is

Ok found that one as well, don't think my walkman would support that encoding.

The walkman probably wouldn't support flac, also takes up quite a lot of space.

VBR allows the bitrate to vary throughout the MP3 so some parts may be 32kbps, some 112kbps, some 128kbps, some 192kbps and some 320kbps for example. So you don't have to waste 320kbps on parts that are fine at 23, 112, 128, 192 etc, but use higher bitrates on parts that need it.

BexTech

tradetime wrote: »

Ok, personally I don't really notice any difference between mp3 and cd, though in all fairness, I have not listened to a cd on anything other than computer speakers fo so long, and they would not do it justice.
On the bitrate, I have ripped at both 128 and 320, and if I am honest, I can't really tell the difference.

If you can't tell the difference, then go with the one that uses the least file space. Though maybe try VBR 32-320 if you have that option.

Myself I can usually tell whether something is an MP3 or CD and can usually tell a CD made from an MP3 than one a direct copy or the original