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IronFilm

Zoom F6 (a 32bit recorder!)

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2 hours ago, Mattias Larsen said:

Can NLEs export 32 bit aafs/omf/xml? Can all of them import 32bit even? 

 

I edit primarily in Premier Pro, and it does support 32-bit floating point. I believe it's the only NLE that does. I do not think / know if Avid Media Composer or Final Cut Pro X support anything higher than 24-bits integer. If they do not support the higher bit depth (or sampling rate for that matter), the NLE would conform the file to the sequence settings (usually 48k / 24-bits), which would be fine. With proper gain staging, a 32-bit float file would look and sound just fine in any sequence. The issue would mostly be if the NLE conforms a 32-bit float file that's been gain staged too low. Post sound would have to replace all the sound from the EDLs with the original production sound files to be able to take advantage of the 32-bit float and add as much gain as needed.

 

4 hours ago, JayKay said:

32bit float on the other hand allows the signal to go above 0dBFS and can still capture it just fine.

You could then turn down the audio in post and save all the audio above 0dBFS with the 32bit float file, which wouldn't be possible with 24bit file.

 

0dBFS represents the maximum signal level in the digital domain, regardless of how many bits the file is recorded with.

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6 hours ago, Olle Sjostrom said:

Still, what does it sound like? And also, file sizes? 

Nobody really knows yet, as nobody outside Zoom has got their hands on a demo unit to test. 
But the pre amps are the same as in the other Zoom F series, or in other words: they've very good. 

 

As for file size? 32bits is double the file size of a 16bit file, which is very very tiny. Unlike camera department recording raw, I don't think we've got anything serious to worry about here for data management of 32bit recordings. The biggest worry is post handling it, would never do this without getting the OK from post first as it is very nonstandard. 

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I just think the 32 bit thing is kind of pointless, seeing as people have been able to get good audio out of the zooms in the past and other brands, even on tape. I don't believe it will have a strong impact on our workflow. As of now it's just a selling point. 

However, it's fun to see that zoom are strong believers of "we'll fix it in post". Because if anything, 32 bit workflow and being able to not gain stage properly will only mean more work afterwards. 

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8 hours ago, Jose Frias said:

0dBFS represents the maximum signal level in the digital domain, regardless of how many bits the file is recorded with. 

 

That's true for when you are capturing audio. In the process of analog to digital conversion, 0dBFS is really the maximum signal level you can record without clipping. But once you have your signal in the digital domain and in 32bit float you can go above 0dBFS. This has to do with how 32bit float is encoding the data.

 

You can try it yourself: Take any sound file in your DAW. Your DAW has to work in 32 bit float. Then apply a lot of digital gain to your audio, so that it goes above 0dBFS. Export this sound file as 24bit int and also as 32bit float. Import these two files again and use digtal gain to lower their amplitude. You will see that the audio in the 24bit file is clipped at 0dBFS and with the 32bit float file you can recover the audio above 0dBFS just fine.

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7 hours ago, IronFilm said:

32bits is double the file size of a 16bit file,

 

Please, do the math properly. It's not hard.

32 bits / 8 equals 4 bytes.

With a 8 channel recording, and sample rate of 48000 samples per second, your data rate is

8 hannels * 48000 samples per second * 4 bytes per sample  = 1536000 bytes per second

1536000 / 1024  (to get from bytes to KiloBytes) = 1500

Divide again by 1024 to get from KiloBytes to MegaBytes, and you have 1.46 MB/sec

 

Then you have to add a tiny bit for header / metadata info, but (unless you have a Cantar) that is just a few KB.

 

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5 hours ago, JayKay said:

 

That's true for when you are capturing audio. In the process of analog to digital conversion, 0dBFS is really the maximum signal level you can record without clipping. But once you have your signal in the digital domain and in 32bit float you can go above 0dBFS. This has to do with how 32bit float is encoding the data.

 

You can try it yourself: Take any sound file in your DAW. Your DAW has to work in 32 bit float. Then apply a lot of digital gain to your audio, so that it goes above 0dBFS. Export this sound file as 24bit int and also as 32bit float. Import these two files again and use digtal gain to lower their amplitude. You will see that the audio in the 24bit file is clipped at 0dBFS and with the 32bit float file you can recover the audio above 0dBFS just fine.

 

This is correct, but we are talking about the 32-bit floating point in a >>recording<< application when it comes to the F6. Your original comment I quoted made it seem that you can still >>record<< above 0dBFS: "32bit float on the other hand allows the signal to go above 0dBFS and can still capture it just fine".

 

Unless Zoom is doing some magic I'm unaware of here, their double ADCs are still bound to a fixed point / integer math, and unless they calibrate 0dBFS to not represent the full scale of their ADCs, then 0dBFS does in fact represent the the maximum signal you can >>record<< before clipping.

 

 

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Nonobstant everything that's being said about the 32bit technicals, I'm kind of curious to try it when it launches just for form factor; the idea of only riding levels instead of gain+levels usual combo, and a center lcd on a not so wide unit is a good thing for one hand operation while the other holds the boom.

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my understanding has always been that any bits get added to the bottom of the scale. unless something changed i would think that those extra 8bits get placed at the bottom of the scale not in the 0 dbfs or above the 0 dbfs. 

 

its really not like tape where you can bias the machine differently along with different formulations. 

 

i compare it to overxposing film/sensor. at some point, if its overexposed you lose all details and sich. the magic halpens when you add more shadow details. its the same thing here i feel like.

 

perhaps i’m wrong and 32 bit float goves you bits above 0dbfs. i never record at 32bit fixed or float. 24bits has great dynamic range as it is.

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18 hours ago, Jose Frias said:

Your original comment I quoted made it seem that you can still >>record<< above 0dBFS

I see, that wasn't my intention.

 

18 hours ago, Jose Frias said:

Unless Zoom is doing some magic I'm unaware of here, their double ADCs are still bound to a fixed point / integer math, and unless they calibrate 0dBFS to not represent the full scale of their ADCs, then 0dBFS does in fact represent the the maximum signal you can >>record<< before clipping.

 

I'm with you and think it is very likely that they will use dual 24bit ADCs and stitch their data together in a 32bit float file. Initially 0dBFS of this file would line up with the clipping point of the more insensitive ADC. At this point 0dBFS is of course still the maximum signal level you can record. It is only after the initial AD conversion that you could push values above 0dBFS with the digital gain. But this would then be recoverable because of the 32bit float.

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while I agree that the fix it in post mindset is often problematic, I can think of situations where recorder with dual ADC and 32bit float would be useful.

 

like for example I've done some acoustic concert filming/recording as one man crew for friends, so I couldn't adjust the trims all the time, so I had to record at rather low gain settings where the quiet parts were recorded on very low levels while I still hit the limiters for the peaks. 

 

with a properly designed dual ACD 32bit recorder, I really wouldn't have to worry about this at all since the high gain preamp/ADC would capture all the quiet parts and the low gain circuit would take capture the loud parts and all would be saved in a file format that makes it impossible to clip or distort, no matter what I set the recorder level at, so it's basically set and forget (and even the set part is reduced to setting the mics and not the levels).

of course there would be extra work involved in post, but even if I have my full attention on riding the trims during the performance, I'll still have to do additional levelling anyway and might even fight with the variable levels that are burnt into the recording.

 

 

I also agree that we can make perfectly fine recordings with the current gear, but personally I think the main reason that prevents 32bit float from being useful is just the post workflow/tools are not established yet because the idea of having a recorder which can basically capture the full output range of any mic without any clipping or distortion sure sounds intriguing to me.

chris

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