Whats the deal with Sampling rates

[tarrickb]

just wondering, what is the advantage to having a sampling rate of 48,000Hz compared to something like 24,000 or even 16,000 Hz. Looks like all audio in these sampling scenarios all have the same file size so i'm just wondering what the advantage to a higher audio sampling freq is.
thanks

[guns1inger]

Accuracy and quality. The higher you go, the better it is.

[celtic_druid]

Well it means samples per second, the more samples, the closer to the analogue source and with a raw source, there is a difference in size.

Say your source is 16bit/2channel. That means 2*16bits per sample, so 4bytes per sample. 48KHz means 187.5kB/s where as 24KHz will be half that.

Of course for a compressed format, there is no difference. 192kb is 192kb, that is why for say a really low bitrate mp3 it will sound better at a lower sample rate... Not enough bits to go around. Given a high enough bitrate though 16KHz will sound much worse than 48.

[Supreme2k]

Unless you're talking audio only, 48k is the DVD standard. Anything lower won't be compliant (as your authoring tool will tell you).

[greymalkin]

the sampling theorum states that if you sample @ 2x the highest frequency of the transmission you will be able to capture all the information from the signal....this is speaking of analog data but it's a good idea to keep your sampling rates above 40,000samples/sec as your standard audio will have a peak frequency of 20,000Hz.

44,100samples/sec is cd standard and as was stated before, 48,000samples/sec is dvd standard. If you want to reduce the filesize you cannot change the sample rate but you can change the bitrate, although your audio signal will suffer from more quantization noise as a result. If it's just a speech or something you can get away with more than if it were a music track.

[tarrickb]

You guys think there is are any guidline indicated preferred bitrates with frequencies?
i'm tranferring video to my phone and have audio at 32-64bits/second. At what frequency do you think I will actually start hearing reduction in quality?

[lordsmurf]

Loss depends on quality of listening device.

[Jester700]

LS is right - in a phone you can get away with a lot. The problem is, those little speakers can still give you high frequencies, and that's where the worst smearing & artifacts will happen. Try both 64 and 32 and see what you like. The source (music vs. speech) makes a difference as well.