24/96 wav >24/48 wav :: do I need to dither?

[macdaddy]

Since the word length was staying the same I wasn't sure...

Thanks, in advance.

[kcmule]

Dither is for dropping bits, not converting sample rates.

[JasonSobel]

Dither is for dropping bits, not converting sample rates.

true, but...

Since the word length was staying the same I wasn't sure...

It's not really.  Any good resampling program is going to process the data internally at either 32 bit or 64 bit when converting the sample rate from 96 kHz to 48 kHz.  So the answer is yes, you should apply dither after resampling to get the data back 24 bit.

[macdaddy]

All converters have sufficient analog noise to self-dither to 24 bit.  If you have digitally processed the signal in such a manner as to push that noise floor below 24 bit resolution, then you would need to dither.  But I would question that signal processing chain if that was the case.

Also, a quality sample rate conversion routine should take into account the need to dither its own algorithms.

Is that a "no..?"

Thx for the replies.

[EarlyMorningRain]

I just use R8Brain and call it a done deal

[gratefulphish]

Dither is for dropping bits, not converting sample rates.

true, but...

Since the word length was staying the same I wasn't sure...

Even though most post-processing programs take the data to a 32 bit "float" while you are editing, I thought that once you then saved the project, it automatically re-dithered [if that is a word] back to 24 bit, without the need to do anything else.  Please let me know if I am wrong, or if it causes any known problems if not done on a separate basis.

It's not really.  Any good resampling program is going to process the data internally at either 32 bit or 64 bit when converting the sample rate from 96 kHz to 48 kHz.  So the answer is yes, you should apply dither after resampling to get the data back 24 bit.