DITHERING...A few questions...

[bigwillz24]

Heh bleyrad beat me to the punch...

 

[Jonny Mumra]

http://www.izotope.com/products/audio/ozone/OzoneDitheringGuide.pdf

This will get ya going.

Cheers

 

[teainthesahara]

Ok, a question. If you load a 24-bit file into Sound Forge and then save as a 16-bit/44.1 file, does it do all these conversions automatically? Or should all the dithering, reshaping, etc., be done BEFORE saving as 16-bit?

Can anyone comment some more on that? If i run a limiter, say the L2 on a 24bit file, or use mastering software to render a file with dither applied, then the resultant wave form will still be at the original bit depth, but dithered. When i take this file, and simply "save as" as a 16bit file, the dither has already been applied, and im just truncated stuff that has already been dithered? Is that correct?

 

[bleyrad]

Dood, I meant the LSB when it is at the higher bit depth. I ain't stoopid you know.

First, "least significant bit" just means the lowest bit. You can't just use it to describe a whole whack of bits below the target depth and expect that people are going you know what you're trying to say.
Secondly, dither has nothing to do with making those bits "unneeded." If you want full resolution, you still need them. If you want to truncate... well, you wouldn't need them regardless of whether or not you used dither.

And by your awesome "street-speek" spelling I would probably challenge your last statement... but whatever.

 

[teainthesahara]

I could go on and on, but it is REALLY important that you have the terminology right. You can apply dithering to a file, and still keep the file as the same bit depth. To change the bit depth, you must truncate the file!

Get it?

After you apply the dithering, is there any way to tell the difference between the files (besides listening, of course)?

 

[wil]

After you apply the dithering, is there any way to tell the difference between the files (besides listening, of course)?

Yes, import the 2 files into a program like wavelab.
If using wabelab open the FFT visual.
Press play have a look at the noise floor on both files.
You will see exactly where the dither is applied.

 

[teainthesahara]

Yes, import the 2 files into a program like wavelab.
If using wabelab open the FFT visual.
Press play have a look at the noise floor on both files.
You will see exactly where the dither is applied.

Cool, thanks man.

 

[wil]

Can anyone comment some more on that? If i run a limiter, say the L2 on a 24bit file, or use mastering software to render a file with dither applied, then the resultant wave form will still be at the original bit depth, but dithered. When i take this file, and simply "save as" as a 16bit file, the dither has already been applied, and im just truncated stuff that has already been dithered? Is that correct?

Yes. The dither in the 24 bit file will be lost.
Most dither give the option of applying it at 16 bit. So A 24 bit file
proceed with your mastering chain. Last plug Dither set to 16 bits.
The dither will be applied at the 16 bit noise floor. If you set the dither for 24 bits it will get lost in the truncation.

 

[Jonny Mumra]

Yes. The dither in the 24 bit file will be lost.
Most dither give the option of applying it at 16 bit. So A 24 bit file
proceed with your mastering chain. Last plug Dither set to 16 bits.
The dither will be applied at the 16 bit noise floor. If you set the dither for 24 bits it will get lost in the truncation.

Well said.

 

[BigRay]

RAMI, I am American . I am a diplomacy officer here in Germany. the tasmanian devil avitar dude was right. on the one term I used the wrong word. Anyway, read the documents I gave you and you will have a good understanding of what it is. Simply put though, below:.
I had it right though..save one word., was a little sauced last night and stumbled over my fingers.
Good luck . You still want to do all editing BEFORE resampling/dither.




truncate
To cut off leading information from an audio signal without regard to the accuracy of the remaining information. Truncation occurs when a signal is converted into a new format that is smaller than the original.

Dither is a form of noise, or 'erroneous' signal or data which is added to sample data for the purpose of minimizing quantization error. Dither is routinely used in processing of both digital audio and digital video data. Jitter is not synonymous with dither.

The simplest way to change the duration or pitch of a digital audio clip is to resample it. This is a mathematical operation that effectively rebuilds a continuous waveform from its samples and then samples that waveform again at a different rate. When the new samples are played at the original sampling frequency, the audio clip sounds faster or slower. Unfortunately, the frequencies in the sample are always scaled at the same rate as the speed. In other words, slowing down the recording lowers the pitch, speeding it up raises the pitch, and the two effects cannot be separated. This is analogous to speeding up or slowing down an analog recording, like a phonograph record or tape.

 

[RAMI]

Sorry Ray. I should have added that I thought your English was perfect other than the fact that you might have used a term wrong. I just thought you were jumped on pretty quick, so tried to come to your defense...lol.

 

[BigRay]

Thanks Rami, no offense taken at all, my friend. I dont worry about some random person rebutting what I say. I am confident in what I know , so its all good.

Hope you get it all sorted out. It gets complicated at times.

Teddy

 

[7string]

Dither & Yon

I'm just wondering here. I'm assuming that if I intend to send my stuff out for mastering I don't have to dither, since I'll be sending out 24-bit tracks? The dithering should only be done IF the intention is to burn to CD, correct?