"alexy" wrote in message
:

Andrew Barss wrote:

I was in error -=- but the compression rate used by iTunes, and as far
as
I know *all* online music services, is compressed in the 128kbps range.
That really is quite lossy, and way below the amount of data that a CD
encodes.

Uh, a CD samples at 44kHz. 128 is not "way below" 44.

What is the relationship between a sampling rate in kHz and a bit rate
in kbps?

In the world of digital audio they are two different things. What follows is
purposely a _very_ simplified explanation, so if some dip**** wants to get
anal, GFY in advance:

The "bit rate" defines "resolution", or the number of bits used to define
the sample, and directly correlates to the "dynamic range" available in the
digital recording (difference between the lowest and loudest sound).

A CD is 16 bit resolution, a standard mp3 is 128 mbps

The "sample rate defines" how frequently the sound is sampled and converted
to digital, and directly correlates to frequency response of the digital
recording. Without going into the sordid details, the frequency response of
a digital recording is roughly twice the sampling rate. A CD has a sampling
rate of 44.1 kHz, which means the highest frequency that is reproduced is
roughly 88.2 KHz.

(Although you can't hear this high, these higher frequencies do color the
sound at audible frequencies, which is why an old fart recording engineer
like me can still record and mix past the prime of my current set of ears.)

A CD is standardized at a 44.1 kHz sampling rate, and a standard mp3 also
has a sampling rate of 44.kHz.

...basically, if it sounds good to your ears, that is all that counts.


--
www.e-woodshop.net
www.hsound.com
Last update: 10/04/04