ESI Waveterminal 2496 - Manual (Page 29)

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S A M P L I N G R A T E
Sample rate determines the samples per second that is used to convert analog audio to digital
audio.
As most of you may know, sample rate for CD-DA is 44.1kHz and professional digital
audio masters are usually recorded at 48kHz sample rate. WT2496(and all other audio cards
with 96kHz sample rate capability for the matter), maybe used to sample analog audio at
96kHz, but at some point in time it must be convicted down to 44.1kHz for it to be used in a
viable consumer format, such as CD-DA. It’s important to keep in mind that 24bit 96kHz
sample rate offers you the highest digital audio quality currently available – so long as it is
kept in that format. Once you convert(dither) the data down to a lower sample rate format,
you will experience some losses in dynamic range and/or frequency response. However,
analog audio recorded with higher sample rate and bit resolution will sound cleaner and
retain more accurate frequency response when they are dithered down to lower bit rate or
converted to lower sample rate.
When choosing an unconventional sample rate, make sure your digital audio software can
support that format. For example, if you select 96kHz on WT2496 control panel, yet your
software can only support 48kHz, it will either play the sound at half the normal speed or not
playback at all. In either case, it just ends up taking up more hard disk space without any
benefit to sound quality.
R E A L T I M E S A M P L E R A T E C O N V E R T E R
The WT2496 can function as a real-time sample rate converter. This is the WT2496’s
unique function that you cannot find on any other digital audio interface. You can change
the incoming digital signal to a different sample rate by choosing Internal word clock, click
the ON button to enable the function and select a desired sample rate. The maximum
conversion ratio is 3:1, so if your input signal’s sample rate is 32kHz, you can convert it
down to 11kHz (32/3) or convert it up to 96kHz (32 x 3). Real Time Sample Rate
Converting functions only for an incoming digital signal. Connect the digital source to the
Coaxial Input port and turn on the SRC. Choose the desired sampling rate. Now the
sampling rate of the signal you receive from the digital output port is converted.
However, you cannot change the sampling rate of .wav files that play back through the
application. If you try to convert it, it only sounds like sampling up (faster speed than
normal) or sampling down (slower than normal).