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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: taper420 on February 04, 2012, 08:19:24 AM

Title: Should you dither going from 32bit (float) > 24bit (fixed)?
Post by: taper420 on February 04, 2012, 08:19:24 AM
And any special settings to consider?

I'm using Adobe Audition FWIW.
Title: Re: Should you dither going from 32bit (float) > 24bit (fixed)?
Post by: Drgiggles1 on February 04, 2012, 11:12:03 AM
Usually you should only dither down from 32 bit float is if you did mastering work on the wav file. If you only delete dead space before and after a show no need to dither. Just click "save as" and in the options choose 24 bit, make sure dither is unchecked, and also uncheck save non-audio information. I've been told by an engineer that the dither on AA is shit and it's best to use a software with MBIT+. He also told me sometimes it's just plain better to truncate than to dither in AA.
Title: Re: Should you dither going from 32bit (float) > 24bit (fixed)?
Post by: page on February 04, 2012, 02:54:51 PM
Usually you should only dither down from 32 bit float is if you did mastering work on the wav file. If you only delete dead space before and after a show no need to dither. Just click "save as" and in the options choose 24 bit, make sure dither is unchecked, and also uncheck save non-audio information. I've been told by an engineer that the dither on AA is shit and it's best to use a software with MBIT+. He also told me sometimes it's just plain better to truncate than to dither in AA.

I agree with all of that. excellent summary.
Title: Re: Should you dither going from 32bit (float) > 24bit (fixed)?
Post by: SmokinJoe on February 05, 2012, 02:47:36 AM
I don't think it really matters. Reason, a floating point number holds info like xxxxxx*10^yy (mantissa and exponent). 32 bit floating point is stored in a computer cpu as 23 or 24 bits of mantissa and the other bits are exponent. Saving to 24 bit is basically keep the mantissa and forget the exponent.  So it's not at all the same thing as going from 24bit to 16bit.  I expect those checkboxes in the software screen don't mean much at all in this case, but possibly make the software do a lot of exta math for nothing.
Title: Re: Should you dither going from 32bit (float) > 24bit (fixed)?
Post by: taper420 on February 05, 2012, 03:08:21 AM
All good info. unfortunately more times than not, I am doing some slight mastering... usually a normalize to bring the levels up to 98.5% (or to lower them and avoid the few clips I may have - and yes I know this doesn't repair the clipped audio, but it brings the clip down below clipping on playback).

So assuming I do perform a normalize, I would want to dither down to 24bit. Not sure that this means anything, but the raw audio is being recorded in a float format, it's not that it's being converted to float just inside the DAW.

Honestly I would just convert to wavpack and share those files (similar compression ratio to flac, yet supports 32bit float), but this is not a standard sharing format, and can't be uploaded to archive or etree.

Now for mbit+. Right now I'm in no type of financial situation to be buying new software, so what's the best free/already owned option out there. Other than Audition I have Audiodesk (stripped down version of Digital Performer) and Soundtrack Pro (along with the whole FCP suite). Of course I have Audacity too, but I can't imagine that being better than Audition. I also notice that quicktime and toast can convert formats, but I'm pretty sure they just truncate.

oh yeah... if you haven't realized it yet, I'm on a mac
Title: Re: Should you dither going from 32bit (float) > 24bit (fixed)?
Post by: Brian Skalinder on February 05, 2012, 10:50:09 AM
I used CEP / Audition for a couple years.  Granted, I liked MBIT+ dither & noise shaping better once I got it, but FWIW I found CEP / Audition's dither just fine.