Zoom F6 - game changer?

[SR]

"If you're recording in 32bit, you don't need to set gain at all." - Watch from 3:00 to 4:00.

Okay, I didn't even know this was possible. The rep compares it to a raw photo.
 

 

 

[kye]

1 hour ago, SR said:

"If you're recording in 32bit, you don't need to set gain at all." - Watch from 3:00 to 4:00.

Okay, I didn't even know this was possible. The rep compares it to a raw photo.

Well, he gets 10 points for shock value.  But so does every Apple iPhone marketing campaign..

I think comparing it to a RAW photo is an excellent comparison.  Imagine I showed you that you can shoot a raw image really dark and then I can bring up the levels in post and it looks fine, well, that's one thing.  Imagine then that I said you never need to adjust exposure - that would mean that if you used it in the way that a normal photographer used it then you'd be fine, but that's not what I said, I said never..  which wouldn't actually work in some situations.

32-bit recording is probably really great, and the noise of the preamps in it is probably very low, but I suspect there are limits and although it's just not very likely that someone will hit them, that's still a very big difference to them not actually being there, which is what he implied.  The legal disclaimer for that claim would be very long and have much fine print to go along with it.

[SR]

1 hour ago, kye said:

32-bit recording is probably really great, and the noise of the preamps in it is probably very low, but I suspect there are limits and although it's just not very likely that someone will hit them, that's still a very big difference to them not actually being there, which is what he implied.  The legal disclaimer for that claim would be very long and have much fine print to go along with it.

He did say it's very good for loud sounds. Not the best for soft ones.

[KnightsFan]

The difference with photography is that you are never in a situation where your lens clips yoyr highlights, whereas a microphone has a dynamic range. If the 32 bit recording has more dynamic range than the microphone, then yeah, you would never need to adjust gain. Basically all they are saying is the digital recording format is no longer the limiting factor in dynanic range, it's the microphone itself.

[Shirozina]

You still need to set the input level to the A/D and you can still overpower it - after that 32bit just means you can digitally add gain to the data to normalise it without it falling apart. The controls on the front are faders and not analog gain. Does it have an analog input gain control?

[Mako Sports]

The whole "gain doesn't matter" thing kinda blew my mind. Audio industry seems to move at snail pace compared to photo/video

[Shirozina]

9 minutes ago, Mako Sports said:

The whole "gain doesn't matter" thing kinda blew my mind. Audio industry seems to move at snail pace compared to photo/video

Digital Audio is a much more mature tech than photo/video so development has leveled out. Microphones have hardly changed in a long long time with the latest designs being with ambisonics rather than single mics. Digital recorders are already very good and it's as much about form factor and features as it is about the sound quality (although there are differences if you have a 'good ear') 

[KnightsFan]

18 minutes ago, Shirozina said:

You still need to set the input level to the A/D and you can still overpower it - after that 32bit just means you can digitally add gain to the data to normalise it without it falling apart. The controls on the front are faders and not analog gain. Does it have an analog input gain control?

It has two ADCs. If you overpower the higher gain one, it still has the lower gain one. If you overpower the lower gain one, then your microphone is already distorting (according to Zoom) and no amount of gain reduction will fix it. It doesn't look like you have any control over either of the gain settings on the ADCs.

[majoraxis]

He said the sound quality would be the same for loud vs soft sounds, so you just have to turn it up in your DAW.

I does not seem like this can function as a USB audio interface. Using it for a dual purpose - field and studio, would help offset the cost. Hopefully they will include that as an option.

If it works as advertised, it will be super useful to not to have to worry about setting/riding levels to optimize signal to noise and to avoid peaks.  One less thing to have to get perfect in the field under pressure - it is like shooting RAW for audio.

This makes a strong case for running your lav mic with an XLR termination directly into the F6 as apposed to wireless, which I anticipate in many cases will have less dynamic range.

 

                               

 

[IronFilm]

4 hours ago, SR said:

Zoom F6 - game changer?

No, it is not. At least not in my  world. 

Perhaps it is as a "game changer" for a certain market niche of people who are somewhat clueless at audio but are doing it themselves the entire workflow from start to finish. 

But in my line of work I'd be moving backwards from my very excellent Zoom F8n, and what would I get in return? Next to nothing. I'd "gain" a nonstandard file format which "solves" a problem I don't have. (I could easily come up with half a dozen things I'd rather see instead from Zoom first)

 

1 hour ago, KnightsFan said:

The difference with photography is that you are never in a situation where your lens clips yoyr highlights, whereas a microphone has a dynamic range. If the 32 bit recording has more dynamic range than the microphone, then yeah, you would never need to adjust gain. Basically all they are saying is the digital recording format is no longer the limiting factor in dynanic range, it's the microphone itself.

At 32 bits, then even if you didn't have a limit with a microphone, you'd find life itself would be a limit to what you record with all 32 bits. To record from one extreme to the next at once would destroy you.

It is like if you recorded a gazillion stops of dynamic range of light with your camera, it would be both so hot and so cold that you'd be DEAD. 

[BTM_Pix]

44 minutes ago, Shirozina said:

Microphones have hardly changed in a long long time with the latest designs being with ambisonics rather than single mics.

Even those are no spring chickens either as the Soundfield microphones were first commercially available over forty years ago now.

The expiration of the patents for the Soundfield and there being more of a market for the content through surround formats and latterly VR has brought them more to the fore in recent years.

Funnily enough, Zoom themselves do a combined ambisonic mic and recorder called the H3-VR which gets zero coverage but is actually a very capable little tool for anyone that wants to try the format.

[SR]

This is mostly voodoo for me. But for anyone interested, more explanation:

 

 

[kye]

I love this topic!

The way that audio circuits work are actually very simple, and the audio industry has taken some principles, applied them in slightly different ways and made new words for them ("gain control", "fader", "input levels adjustment", "microphone/line level switch", etc are all electrically the same function) and so they take a new product, re-arrange the gain structure, and now they get to make spectacularly stunning statements that sound groundbreaking but are actually almost irrelevant.

One of the main jobs of a professional audio engineer is to select audio equipment, connect the devices together in the right way, and adjust the settings on each of them so that the levels all the way through the signal path are high enough that noise doesn't creep in, and low enough so that nothing clips.  Depending on how many devices you use, the signal path can have half a dozen or so different controls and another dozen amplifier circuits designed by the manufacturer.  In this device it looks like Zoom took two of them, adjusted the gain on one of them, made the second one more accurate, changed the names and are calling it a revolution.

[UncleBobsPhotography]

6 hours ago, kye said:

In this device it looks like Zoom took two of them, adjusted the gain on one of them, made the second one more accurate, changed the names and are calling it a revolution.

They also changed it to using floating point instead of integer values. For those not familiar with computer science, a floating point is a number which is divided into 2 parts. The one part has a certain amount of bits to represent "how many zeros" there is in the number (or the exponent), while the rest of the bits are used to represent a certain number of decimals.

An example: The number 1234567890 would usually be represented just as it is. In floating point it could be represented by 1.23456*10^9 by only storing the 7 first digit and the exponent 9.

If they use 24 bits to represent the precision and 8 bits to represent the exponent, they will get the same precision as with normal 24 bit recording, but they would get the same precision whether the number was small or large and they would get a much larger value range.

For more info: https://en.wikipedia.org/wiki/Single-precision_floating-point_format

How well using floating point numbers works in reality is a whole other matter, and the only way to find out is to test it.

[IronFilm]

 

[SR]

On 4/11/2019 at 5:01 AM, kye said:

I love this topic!

The way that audio circuits work are actually very simple, and the audio industry has taken some principles, applied them in slightly different ways and made new words for them ("gain control", "fader", "input levels adjustment", "microphone/line level switch", etc are all electrically the same function) and so they take a new product, re-arrange the gain structure, and now they get to make spectacularly stunning statements that sound groundbreaking but are actually almost irrelevant.

One of the main jobs of a professional audio engineer is to select audio equipment, connect the devices together in the right way, and adjust the settings on each of them so that the levels all the way through the signal path are high enough that noise doesn't creep in, and low enough so that nothing clips.  Depending on how many devices you use, the signal path can have half a dozen or so different controls and another dozen amplifier circuits designed by the manufacturer.  In this device it looks like Zoom took two of them, adjusted the gain on one of them, made the second one more accurate, changed the names and are calling it a revolution.

Ah, a complete dummy when it comes to audio here. So this isn't a big deal at all, if I'm reading this correctly. Is there any truth to their claim of more dynamic range? I thought this might be useful on projects where clients are too cheap to pay for a proper location sound guy (too many situations like that).

[scotchtape]

I just invested in a Mixpre-3 a few months ago.

If this thing has a good headphone amp maybe I'll switch, NEVERGAIN!  That would be amazing!  

Now if they would hurry up and do this for images as well, no more setting exposure... woo!

I wonder how much the file sizes are affected.

[KnightsFan]

@SR It's absolutely a big deal, but primarily for non-pros. I believe what @kye is saying is that Zoom didn't do anything particularly difficult--it's not like they completely redesigned how the circuitry works. It's similar to the dual channel recording feature many recorders have had for years, except that it merges the two files automatically into a 32 bit file, instead of giving you two 24 bit files that you can manually splice if you so desire.

But it's absolutely a useful feature, especially for one man bands who don't have enough eyes to watch the camera and the audio meters at the same time, or for ultra low budget projects (like mine) who employ non-pros without much experience.

The dynamic range of the audio file should increase dramatically.

 

15 minutes ago, scotchtape said:

I wonder how much the file sizes are affected.

32 bit 48kHz is exactly twice the file size of 16 bit 48kHz, not including the negligibly small amount for metadata.

[HockeyFan12]

On 4/11/2019 at 1:52 AM, UncleBobsPhotography said:

They also changed it to using floating point instead of integer values. For those not familiar with computer science, a floating point is a number which is divided into 2 parts. The one part has a certain amount of bits to represent "how many zeros" there is in the number (or the exponent), while the rest of the bits are used to represent a certain number of decimals.

An example: The number 1234567890 would usually be represented just as it is. In floating point it could be represented by 1.23456*10^9 by only storing the 7 first digit and the exponent 9.

If they use 24 bits to represent the precision and 8 bits to represent the exponent, they will get the same precision as with normal 24 bit recording, but they would get the same precision whether the number was small or large and they would get a much larger value range.

For more info: https://en.wikipedia.org/wiki/Single-precision_floating-point_format

How well using floating point numbers works in reality is a whole other matter, and the only way to find out is to test it.

Thank you, I'd never totally understood this until you explained it so well. 

What is preventing video and stills cameras from similarly expanding their dynamic range? I suppose it's the limitations of the ADC rather than how the signal is quantized? 

In a way, it sounds like F6 is doing exactly what the Alexa is doing except for audio: using two ADC stages, merging them, then quantizing and representing the data in a logarithmic rather than linear representation? Is float roughly analogous to log?

 

[kye]

6 hours ago, KnightsFan said:

@SR It's absolutely a big deal, but primarily for non-pros. I believe what @kye is saying is that Zoom didn't do anything particularly difficult--it's not like they completely redesigned how the circuitry works. It's similar to the dual channel recording feature many recorders have had for years, except that it merges the two files automatically into a 32 bit file, instead of giving you two 24 bit files that you can manually splice if you so desire.

But it's absolutely a useful feature, especially for one man bands who don't have enough eyes to watch the camera and the audio meters at the same time, or for ultra low budget projects (like mine) who employ non-pros without much experience.

The dynamic range of the audio file should increase dramatically.

 

32 bit 48kHz is exactly twice the file size of 16 bit 48kHz, not including the negligibly small amount for metadata.

Good summary.

I'm a bit skeptical about the usefulness of it.  Not to say that it won't be more useful than a normal device, but my question is how much more useful.  I think that noise may play a big part in limiting how much extra dynamic range there is.  The idea is that in traditional system you want to keep the levels in the sweet spot where they are below the clipping point, but above the point where the noise starts to become audible.

An audio engineer will adjust their equipment so that the signal is in that sweet spot through every piece of equipment in the signal path.

The problem comes if we don't adjust the levels when we go from one situation to another.  Here is how different situations can be from one-another:

So, if you set the gain for a noisy street scene where the levels were in the 80-90dB range and then didn't adjust it when you shot the two people talking quietly in bed scene, the bedroom scene would be 60db quieter than what an engineer would set it to.

We set the street scene so that the peaks are at -20dB, and we're good to record 70dB of dynamic range because the normal system is fine to about -90dB.  We probably don't need the full 70dB, so there's some wiggle room in there.  But now were in the bedroom scene and the peaks are at -80dB (because 60dB quieter than our -20dB peaks is -80dB) and with a normal system this means we have less than 20dB of dynamic range there, assuming that at -100dB is where the noise floor is.  A normal 16-bit system would be awful quality here, but let's put that aside, because we're now talking about the F6.

The Zoom F6 may very well be able to go down to (let's say) -200dB.  This is my estimate, but if 16 bits can do -96, 24 bits can do -144, 32 bits should be around -200dB.  The problem we're going to have is noise.  I'm not sure that the F6 will have input circuitry that has a noise floor of -200dB (that is very very very low noise levels), but let's assume that it does.

The problem is that your microphone probably doesn't.  Anything that needs phantom power requires it precisely to run its own internal amplifier circuitry, and every microphone on the planet is built for the -96dB levels of 16-bit.  For example the Sennheiser 416 has a signal-to-noise ratio of 81dB.  If you used this mic then your lovely F6 would be making a very high quality recording of your actors mixed with a very high recording of the microphone noise, and both your actors and the microphone noise would be at the same volume level!

Win!!

I don't know if the 416 is that good a microphone, but even if we had a mic with SNR of 100, or 120dB, that's still only putting your noise floor of the bedroom scene 20dB or 40dB lower than your actors, and that's not a great end result.

If I've done some maths wrong in here please sing out, but I believe the logic stands.  And if anyone thinks that my example is extreme, just imagine a shot of two people walking in the doors of their NY apartment, up the stairs, into their apartment, getting undressed and then into bed.  Not only might you have level problems in one scene, you might have it IN ONE SHOT!