Weird questions about Re-Dithering

[Alécio Costa]

Hi,
a)If you re-import a 44k/16 file you have just mastered (originated from a 44k 24 file) into your typical working session at 44k 24 and just invert PAN (LR to RL), for example. Do you need to redither to go again to 44k 16?

I am aware that every bit truncation needs dithering, but in such funny situation, only zeroes are being applied from bit 17 to 24. Or not?

b)If you Audiosuite a stereo file, which has Dither as a default in preferences, then at latter processing you need to bounce and dither to go to 44k 16. Can it be harmful to the file since it is being double.. triple dithered?

c)Between Power Dither (Level 1,2,3) and TC MD3/4. which one suits best a mastering scenario?

I am asking these curious stuff because for the first time in 10 years of mastering, a client complained that he could listen to dither at his Sony Discman headphones.

Obviously I cured it by cleaning the beginning of the song, followed by a quick fade-in. But now, sound starts almost from nowhere/silence.

[crizdee]

Hi,
Just got to ask!!...
Why are you pulling a 16 bit file in to a 24 bit session? this is asking for trouble, having to do 2x bit conversion just to end back to 16 bit! each dithering stage add small amount of noise!!

I'm no expert by any means!! But Choice of dithering can depend on the source material! what sounds good on a loud rock track may not be so good on a guitar & vocal or something that has very quiet passages. Guess you have to try and find the one that sounds best to your ears and listening very close with headphones is a good way to check the quiet passages to listen for dithering problems. they do vary as well, some filter the dithering noise to make it a higher frequency etc to help in the more critical lower bands.

Ozone 3 Mbit+ is a good dithering algorithm.

[DigiTechSupt]

Chris is right - you should use a 16 bit session, rather than reconverting to 24 bit and back down again.

In doing so, you would not typically need to redither. In fact, if dithering were in question, I'd go back to the original mastering session and do the tweaks there, then possibly try a different dither algorithm to see if it helps.

As for hearing dithering in Sony Discman headphones - it's my guess that something else is going on there, that he's hearing general analog noise, rather than dither. Dither signals are typically way too low in level and too high in frequency for anyone to hear them.

[WildHoney]

Originally Posted by DigiTechSupt

As for hearing dithering in Sony Discman headphones - it's my guess that something else is going on there, that he's hearing general analog noise, rather than dither. Dither signals are typically way too low in level and too high in frequency for anyone to hear them.

I'd agree. More likely he's hearing some noise from an analog modeling plug-in (or an open mic). Good to mute tracks during quiet sections even if there's no audio there when using an analog modeling plug-in.

[crizdee]

Originally Posted by WildHoney

I Good to mute tracks during quiet sections even if there's no audio there when using an analog modeling plug-in.

That's a very good point! I've been using a lot of the Waves studio classic plugs lately and they sure do add up on the noise front? i'll have to start using expander gates again, or automate the analogue modeling where possible!

Good old 80's tape hiss

Chris