+- MacResource (https://forums.macresource.com)
+-- Forum: My Category (https://forums.macresource.com/forumdisplay.php?fid=1)
+--- Forum: Tips and Deals (https://forums.macresource.com/forumdisplay.php?fid=3)
+--- Thread: 32-Bit Float Audio Recording! (/showthread.php?tid=285784)
Pages:
1
2
32-Bit Float Audio Recording! - jonny - 03-21-2024
I am a documentary filmmaker and teacher. This is the first I've heard of 32-Bit Float Audio. It sounds like a complete game changer for documentary (and live music... etc). Does anyone here have experience using it?
https://www.wired.com/story/32-bit-float-audio-explained/
"With 32-bit float recording, on the other hand, applying gain prior to recording isn’t necessary. “When you're recording in a 32-bit format, there is no volume knob, it essentially just creates a mathematical chart of data that it can then interpolate in postproduction,”
Re: 32-Bit Float Audio Recording! - clay - 03-21-2024
yeah, I've heard of it and have a recorder that can record in 32-bit float: https://www.sounddevices.com/product/mixpre-10-ii/ but like you, I don't know that I've fully grasped the benefits of it, either.
My initial take is that it gives you a ton more headroom before clipping, and the opposite is also true -- you can have something recorded at a very low signal and boost it up to usable levels without noise or any loss of quality. I have an engineer friend who had some of the same head-scratching at the debate between 16 and 24 bit recording. I'd guess that the 24 to 32bit jump is a bigger difference than the 16 to 24 bit jump. I kind of understand the "headroom" idea, but not really how it translates into working with files in a DAW or other editor.
Would be happy to learn more about this. At my level and type of client, nobody cares how something was recorded -- they just want decent-sounding audio without a bunch of noise. But I know there are legit reasons for this sort of technology and technique to exist.
Re: 32-Bit Float Audio Recording! - clay - 03-21-2024
as a follow-up, I just followed a link on the product page of the recorder I linked above to a description about 32 bit float: https://www.sounddevices.com/32-bit-float-files-explained/
Lots of technical detail, but I found these paragraphs and the accompanying graphic quite astonishing, honestly:
"The dynamic range that can be represented by a 32-bit (floating point) file is 1528 dB. Since the greatest difference in sound pressure on Earth can be about 210 dB, from anechoic chamber to massive shockwave, 1528 dB is far beyond what will ever be required to represent acoustical sound amplitude in a computer file.
There is one other aspect of 32-bit float files which is not immediately obvious. Files recorded with 32-bit float record sound where 0 dBFS of the 32-bit file lines up with 0 dBFS of the 24- or 16-bit file. Keep in mind that unlike the 24- or 16-bit files, the 32-bit file goes up to +770 dBFS. So compared to a 24-bit WAV file, the 32-bit float WAV file has 770 dB more headroom."
Re: 32-Bit Float Audio Recording! - rich in distress - 03-21-2024
I’ve been aware of it for a long time. Some audio software, like digital performer, convert the audio path to 32bit float before performing calculations to avoid clipping, then return to the original bit depth.
I understand recorders need to have special converters, and I’m not aware of any audio cards with them, so field recorders only.
Re: 32-Bit Float Audio Recording! - Filliam H. Muffman - 03-21-2024
This might be why I like The Weather Channel audio so much better than other TV streams. I get the impression that it allows better filtering of background noise.
I had to dig into the Zoom website a couple of levels to find out it's only 48 kHz sampling. I guess they did that to keep the file size close to that of 24 bit/96 kHz.
Re: 32-Bit Float Audio Recording! - Bixby - 03-21-2024
I use it when I don't have time to check levels. It does eat up more storage space, obviously.
Re: 32-Bit Float Audio Recording! - Filliam H. Muffman - 03-21-2024
For reference, the sound of the Sun at the Earth is estimated to be 110 db to 150 dB (185 dB can kill you). Using an equation* that I believe uses air at atmospheric pressure for the transmission medium for 150 dB gives an estimate of 373 dB at the surface of the Sun.
*Lp2 = 20 log (R2 / R1) + Lp1; 20log((1/149,600,000,000))+150 = 373
Re: 32-Bit Float Audio Recording! - jonny - 03-21-2024
Bixby wrote:
I use it when I don't have time to check levels. It does eat up more storage space, obviously.
What are you using it on? And how is the performance at very low levels?
Re: 32-Bit Float Audio Recording! - Bixby - 03-21-2024
jonny wrote:
[quote=Bixby]
I use it when I don't have time to check levels. It does eat up more storage space, obviously.
What are you using it on? And how is the performance at very low levels?
Sounddevices MixPre-10 II. Mostly classical music and similar. Honestly I still follow good engineering practices and know my recorder and mics well enough that this just covers my butt for the occasional overs. Really haven't tried to capture poor levels. It should just be fine, though.
I'm a big fan of the SD units, use them professionally all the time. They can be used as a computer interface as well, so these along with others are 32 bit float interfaces (vs. only field recorders). I just wish their headphone outputs were a little cleaner.
Re: 32-Bit Float Audio Recording! - August West - 03-22-2024
I'm a big fan of the SD units, use them professionally all the time.
+1
I haven't done this, but sound effect field recordists I know speak favorably about the ability to avoid/never experience overloading the inputs. My Pro Tools internal processing has been 32 bit for a long time.