Dither and sound shaping?

[Bigus Dickus]

I have the options on my A/D converter to use dither and soundshaping before the conversion process. I know sometimes dither is inserted digitally to give a "soft" noise floor for quiet and fade out passages, but I'm not sure if I should use it or not. My guess is that if I need it, inserting it in analog would be preferable, so it's not really something I can "fix in the mix."

About soundshaping... I have no idea what that is or what that does. I read my A/D converter's white paper on it, and did some web research, and none of it really made sense. I generally have a decent grasp of digital audio theory, but this part I'm having trouble finding a good down to earth explanation for.

This is a dbx A/D converter, and I'll be recording in 24 bit. Sampling rate is still up in the air, but I'm leaning towards 88.2 kHz.

Primary recordings will be of a grand piano - classical music mostly, until I get around to writing out some of my own stuff for fun.

Any insights here?

[Son of Mixerman]

Dither is an option to assist in the bit down conversions. The other option is truncation. Truncation is cutting off extra bits indescriminantly, usually easy to hear because fades suck.
Dither is the last thing you should do to your music as it goes to the premaster. If your going to be going to a Mastering Engineer, save your mix at 24/88.1 in the data format on probably a couple of disks, let hte ME worry about dither.
soundshaping is a form of dithering, your just assigning the type of dither based on different algorithms. Its like a tunalbe dither. Leave the dither off until you bounce to 16/44.1 CDR premaster.

SoMm

[Bigus Dickus]

Thanks for the advice. That sounds completely backwards from what my assumption was... you're saying not to use any dithering or soundshaping on the front end, and save that for the last step of resample/downconvert? Okay dokay!

[mixsit]

Perhaps if you were using the a/d at 24 bit but it was feeding a 16 bit recorder, the dither could be used at the a/d stage.
I did this for a while when my RME's were feeding ADATS. (not the dither part though.)
Wayne