12.17.2020

I'm sure everyone has been paying attention to advances in field audio recorders so I'm guessing this post is redundant. But here goes.

 

The big news in digital audio recorders this year is a feature they are calling "32 bit float." 

But let me back up for a second and set the stage. When you leave a completely treated sound studio and venture out into the real world to make videos or movies you are leaving a "safe zone" and heading into a real world filled with background noise, distracting noises and random noises. You try your best to ameliorate as much audible clutter as you can by using the right microphone types, putting up sound absorbing blankets and turning off as many noise making appliances as you possible can. And you lift your headphones off one ear and say, "quiet on the set" whenever you can. That's the nature of location recording. 

If you are not only the sound man but also the camera operator, director and all around only crew member then you've got your hands full.

The biggest issues, after the various controllable noises are taken care of, when recording live sound along with video, are the noise floor of your audio gear and the treacherous thing we call, "clipping." Clipping in audio is a lot like blowing the highlights in a photograph. If you record sounds and all of a sudden an actor or subject gets very loud a traditional recorder will clip hard and introduce a lot of distortion into you audio that's very hard to deal with in post. You can use "limiters" to pull back the audio but it's not the most effective solution. 

At the other end of the spectrum you might have set your levels for a good level while doing your tests but then, in the heat of an interview, the speaker either moves away from your mic or starts speaking so softly that the signal barely registers on your recorder's meters. If your only job is audio it's pretty straight forward to ride the level controls but if your head is in the "visual" and "content" spaces you'll likely overlook the audio spikes and dark holes that will certainly vex you when you sit down to cut your project together. 

Along comes "32 bit float." While nearly every production recorder writes 24 bit audio files the newest generation can write 32 bit files. There's a lot more information and the files are much larger but the wonderful thing is that you don't even need to set levels. You can bring up the quietest passages and you won't get the ever higher noise floor you would with a regular 24 bit file. You can scream at the microphone and as long as your microphone doesn't overload you won't clip the recorded audio. That's so cool. You can let Tom Cruise scream at you and record every tender nuance without distortion. You'll just need to adjust the levels in post. 

The first device I heard about that offered this was a Zoom F6 and the reviews on it were pretty good. Some have mentioned that the audio pre-amps aren't particularly good sounding and that may be so but it sometimes feels (analogy) like people talking about a lens not having that Leica look. The F6 was cool in concept and I guess it's serving its purpose for some users but many were hoping that Sound Devices would come out with an affordable version because people really, really like that company's quiet and clean Kashmir pre-amps. And the way they design their limiters. The limiters have a nice roll off instead of an instant clamping modality. But, of course, you won't need to use limiters with 32 bit float. It's kinda built in. 

Sound Devices launched an updated model of their original Mix-Pre3 audio recorder and, voila! it features the magical 32 bit float. And the Kashmir pre-amps. And you can use it as a high end audio interface for web casts. 

The Mix-Pre3 is set up for professional use and takes three XLR inputs. It will do simultaneous writes on the internal SD card as well as a USB Thumb drive which gives you a back-up of your audio recordings. It can read or write time code and can be powered by double A batteries, an A/C adapter, a power bank via USB-C. Most reviewers are suggesting either the power bank option or an adapter for the battery tray that allows use with Sony NP batteries because the unit does suck down power. 

This machine provides the audio equivalent of a digital camera raw files that never runs out of highlights and has no noise in the shadows. I'm putting this on my Amazon wish list for myself. It'll be right there next to that set of Leica cinema lenses. If you buy the five lenses together the package is just a bit shy of $100,000. 

The Sound Devices Mix-Pre3-ii is much more affordable at around $800. 

But the real story is the 32 bit float. And it is also available on a small, single channel device from a company called, Tentacle. It's a self contained recorder with a supplied lavaliere microphone that's meant to be used in place of a wireless mic set. Just turn on the unit, pop the small box into your subject's pocket, clip the mic onto them and go. You get to set the levels after the fact and it's easier than ever to sync up the audio to your video. That system is a bit less than $400. But you'll need one for each actors or interviewee. 

I can't wait to try out the Mix-Pre3ii. Seems just right for a one man video band. 

Okay. That's it for today.

6 comments:

TMJ said...

Yes, the Mix-Pre3II is a superb audio recorder, I've had mine for almost a year.
It has three mic/line XLR inputs put you can also add more from a mic preamp via the aux input. The ability to make a simultaneous backup to a USB stick is a great feature too. You can also plug a USB keyboard into that slot, which is more useful than you might think I power mine on location from a 20100mAh External Battery via USB. There is now 10 seconds pre-roll recording, a nice feature.

The only very minor downside is that the on/off switch is tiny and hedges in by the USB A and C ports, but then it's a tiny recorder. AS for the 32 bit float - I don't really need it 99% of the time as I record 24/96 and peak at -12dB, so I have massive headroom to begin with.

But you will love it, the ease of use and sound quality are exemplary.

TMJ said...

A quick follow up on power options from my experiences

AA batteries in the included battery sled - works mainly in 'low power state' as cells very quickly exhausted and not worth bothering with, unless in an emergency. Also remember that the SD card sits at the back of the battery compartment

Power from USBA - insufficient current from USBA so still goes into reduced power mode (the power ststus icon turns amber)

Power from USBC - works fine as C delivers the necessary current

The L-Mount battery sled for Sony L-Type batteries. Very bulky and ungainly on a small recorder, only useful if you already posses L-Type batteries.

The Hawkwoods SD1/SD2 Adapter for either 4-pin Hirose connector or DV style battery sled. Really nice, neat, solution and I am about to buy the Hirose version.

In summary, on location I would either use the C power via an external pack, although you have the USBA and on/off switch next to the USBC connector. Or the SD1/SD2 Adapter as an alternative, especially if you already use Hirose type power packs.

Marcio K said...

Zoom have launched a competitor to the Tentacle, the Zoom F2. Gerald Undone have done a good comparison between it and the Tentacle.

But, as a RAW file have more infomation than a JPG, but can only recover highlights and shadows to an extent, I guess that 32 bit-float can recover clipping until some value. Looking for this info but could not find it anywhere.

My interest is about live concert recording, where clipping is a constant issue.

Michael Matthews said...

Best explanation of a complex product and its use I’ve encountered. I want one. Haven’t done anything all year, but I want one. The product description on the B&H website states that it also provides a stereo mix output of all three sources for podcasters and the like, plus the option of a direct 32-bit float stream to a Mac computer. The same product description has a little more detail on the extreme upper limits re clipping avoidance but it comes down to the same conclusion: if you don’t overload the mic there is no problem.

scott kirkpatrick said...

If you have a Mix-Pre2 of the original persuasion, are they upgradeable?

TMJ said...

Hi Scott, unfortunately the original Mix Pre models are not upgradeable, as there are physical electronics changes, rather than only firmware. But the original Mix Pre models are still great machines and the latest firmware gets you the 10sec pre-roll and USB copy. I did look at a MkI just before the MkII came out, but decided the upgraded model was worth it

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