Powr Dither and noise shaping settings, what do they do?

[bouncing balls]

Do they introduce random low level noise at different frequencies (or do they change any frequencies or anything else for that matter?)- or none of the above. I did a search and didn't seem to find a definitive answer.
Thanks in advance for any accurate analysis.
"What's the frequency Kenneth".

[Chief Technician]

Noise shaping exploits the Fletcher-Munson loudness countours. These contours are a graph of sensitivity (in dB) of the human ear across the frequency spectrum. The noise shaping process increases the dB level of the dither noise at frequencies that we are least likely to hear it at. This can be done as opposed to having a uniform level for the dither across the entire frequency spectrum.

I have been told that some old CD players cannot play (or have difficulty with) discs that have noise shaped dither, so be aware.

[Jules]

Yarzzzzzzzzzzzzzzzzzzzz!

[bouncing balls]

Thanks Chief!
It still leaves me perplexed as to what the noise shaping 1, noise shaping 2, and 3 options (settings) under the Powr Dither plug in actually do versus a standard "one size fits all" noise shape setting.
Also, what are my Dither options to avoid the pitfalls as you mentioned? I have seen a third party plug option (or maybe hardware solutions?)--I suppose I should hunker down and do some homework- unless anyone can fire off some quick suggestions...Thanks! B
PS. I'm trying to maintain the ut-most fidelity in my masters throughout the mixdown and bounce process. Or is this a compromise that I'm being too concerned about?

[Chief Technician]

Originally posted by bouncing balls:
Thanks Chief!
It still leaves me perplexed as to what the noise shaping 1, noise shaping 2, and 3 options (settings) under the Powr Dither plug in actually do versus a standard "one size fits all" noise shape setting.

<font size="2" face="Verdana, Arial">The different settings are most likely different noise shaping curves. They probably utilize a few different frequencies to exploit the characteristics of the human ear as well.

Also, what are my Dither options to avoid the pitfalls as you mentioned?

<font size="2" face="Verdana, Arial">The best way to avoid those problems is to use no noise shaping. The problem is rare, and I've used Ultra Type 2 noise shaping on the Waves +L1 without a problem ever, but ymmv.

[l anthony johnson]

Clipped from some info I have around....

#1: uses a special dithering curve to minimize quantization noise.

#2: uses additional noise shaping over a wide frequency range which can extend the dynamic range by 5-10 dB.

#3: uses additional, optimized noise shaping which can extend the dynamic range by 20 dB within the 2-4kHz range - the range the human ear is most sensitive to.

Note: Noise Shaping minimizes side effects caused by bit reduction by spectrally displacing the quantization noise above 10 kHz - the range the human ear is least sensitive to.

The mode which will sound the best to you is primarily dependent on the program material and on your personal taste. The "right" setting is best determined by auditioning the audio material with each of the dithering modes.

Please note:

Dithering the same audio signal multiple times should be avoided.
-----------------------------

hope this is useful to you

anthony
http://mp3.com/ziggy_johnson

[bouncing balls]

Thanks Anthony and Chief!
That's exactly what I needed to know and appreciate the insight.
Have a good one!
B

[MilesWonderland]

If I'm mastering a 24 bit PT session out through waves L2 then to my apogee rosetta, digital out to my CD Burner should I dither with the L2 or let the rosetta do the conversion to 16 bit?????

Thanks!

[Chief Technician]

That depends largely on what you prefer aurally. Waves uses IDR (Increased Dynamic Resolution) and Apogee uses UV22 (which applies noise shaping near the 1/2 Fs value). Do some listening tests with the different dither algorithms and let us know what you hear!

[Zep Dude]

If you really want to hear the effect do this:

Lower your master fader so that the music level is WAY down near the noise floor and crank up your system so you hear music and the digital grunge together. Now just try all your different dithers. You'll very easily hear the difference.

Zep,

MajesticMusic.com
and now,
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