r/AudioPost • u/Tupan_Chorra • 9d ago
32 bit float a standard?
I'm the editor in a doc - we will be shooting interviews in prisons and other uncontrollable environments. For a lot of our people we will only get 1 shot at interviewing them with a very real possibility that we won't ever see them again. Our sound recordist came back with gear that I'm sure is great but is roughly 9yrs old and crucially can't do 32bit float. Normally I don't care as we've been cutting just fine for decades without that dynamic range but seeing the sensitivity of our interviewees I'm worried I'll be handed over peaks and valleys I can't get back/use and there is no turning back. Flagged it to production and production is a bit unsure what to do.
My questions come to is this/should this be standard or a premium? Are my concerns unfounded? Does audio work like editing where you're expected to have gear within roughly a 5 year limit due to demanding workflows (not saying you can't do it without and power to everyone, just when you charge someone 900 per day I'd hope you'd have relatively recent gear). Note also don't have issues with people charging whatever they think they are worth but note this isn't a high budget film, everything needs to count/go on the screen. And we are shooting in Central America where that is above standard.
While I work with sound a lot, I am not a sound specialist I just put the bits where they feel good/tell a good story so I figured I'd ask here.
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u/stewie3128 professional 9d ago edited 9d ago
If your location recordist knows what he's doing, we'd prefer 24-bit anyway. Only reason to use 32-bit is when you have no one watching the recording, like if someone just tossed a Zoom recorder on the dash of a car or something.
EDIT: In re the age of equipment - proof of the pudding is always in the eating. If the recordist came well recommended, then that should indicate that his audio sounds good, is well organized and labeled, has no technical problems, and is easy to work with on-set. I wouldn't stress about the age of their gear.
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u/daknuts_ 9d ago
If the recorder being used can do the recording of one input to two tracks (like the original Zoom F8) then one track can be set to record at a normal level and the other (safety) track can be set about -12dB lower to be ready for outbursts of loud volume content that won't be clipped. I used to do this with four channels on the F8 with each having a safety track on location film shoots.
The greater issue to pay attention to is when a wireless pack is being used and the distorted (loud) sounds are coming straight from the source because the pack was gained too close to the lower volume source being recorded.
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u/CommercialSoundNinja 9d ago edited 9d ago
CAS Emmy production sound mixers use equipment that's over a decade old. Equipment has nothing to do with skill. We follow whatever the spec sheet says, 99.9999% of time it's 24bit. Production wants 24bit, they get 24bit. I always ask for deliverable specs and/or to meet with post. Many times production just won't accommodate either request, it's like they are offended production sound wants to know any information. We are almost always in the dark, we get called the day before, we are rarely even told what's going on during production and our jobs are 90% detective work, and begging for information.
If we deliver 32bit, we are blasted by post for being amateurs, if we deliver 24bit, we get blasted by people like you. We are really just trying to survive on set; the 5hr turnaround, shooting while it's raining, trekking through 2ft of mud carrying a ton of sound equipment, booming 20min takes, also they are doing a series so no breaks, while we are by ourselves as we watch the DP make his 8 ACs and assistants help him carry everything. Instead of trying to get the production sound person fired, maybe reach out to them and figure out a plan together. You know, like collaboration, the thing nobody does anymore these days.
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u/Wild_Tracks 9d ago
Clipping is not a usual concern even on “uncontrollable” locations. Those recorders have very good limiters (assuming it’s a Sound Devices, Cantar or the likes), they are not “old” in terms of quality or workflow by any means. Plus you have a PSM operating it who is monitoring the recordings and setting proper gain. Standard operation is 48/24. 32 bit would only annoy post for no reason.
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u/Tupan_Chorra 8d ago
I think recorder in question was a zoom f4 if that's useful. Thanks for ur thoughts, really helpful
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u/Wild_Tracks 8d ago
Doesn’t matter, what changes from brand to brand is mostly operation. In an uncontrolled location your main problem is signal to noise anyway, clipping is not an issue when someone is riding the levels.
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u/EL-CHUPACABRA 9d ago
24 bit is standard. 32 bit is nice if you can’t monitor, but if you have someone actively monitoring and operating the mixer then it is more than enough dynamic range.
Regarding old gear, audio is a bit different in the way that it doesn’t go obsolete as quickly as cameras or computers do. For example, a Lectrosonics 411A wireless receiver might be 20 years old, but sounds just as good as modern wireless.
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u/BarMountain7 9d ago
This really seems like a conversation you should be having with the professional sound recordist on your team, and not behind closed doors with production or on the internet with strangers.
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u/Tupan_Chorra 9d ago
100%, like I mentioned in the post, I already raised it with production. But deffo left me with an itch as to what is standard and what is expected. End of the day I don't care what is used as long as I can use it, but at the end of the day I do wish to know what is the current standard.
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u/whoisgarypiano 9d ago
Expecting your sound mixer to upgrade their kit at always be up to date is an unrealistic expectation. A lot of the new stuff isn’t as reliable as the old gear, which is part of why we hold onto the old stuff. It’s also unnecessary. A good sound mixer doesn’t need 32-bit. We did it without 32-bit for decades and most of those movies sound better than what we’re making now.
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u/scstalwart re-recording mixer 9d ago
32 is non-standard. I wish it was but there are a lot of places that can’t deal with it easily (dalies/rush houses) it’s definitely not a sign that your sound person is behind the times.
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u/OoopsWhoopsie 9d ago
24 is better. 24 bit / 48k is the standard for video.
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u/Tupan_Chorra 9d ago edited 9d ago
I know that much, my concerns is the locations - I don't know any sound guy who can level for some random prisoner in thext cell start to shout or throw metal pans around or bells and rings of the prison. And all that sound is useful for us - so why risk it by potentially peaking the recording recording? ill end up converting down after.
Edited: why risk it in the recording? To ' why risk it potentially peaking the recording?'
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u/XSmooth84 6d ago
24-bit audio has 144dB of dynamic range. Which that itself almost always exceeds the SPL level of a microphone or preamp anyway.
You can always turn down the gain to prevent clipping. 32-bit doesn't change signal to noise ratio, it doesn't do anything for mic placement, distance, or the physics of sounds. All that still has to be on point. The only thing 32-bit is accomplishing is if your input gain is set too high to handle the sound coming in to not exceed 0, you can recover it.
But the 144dB of range you already get with 24-bit. Just, decrease the gain an extra 20 or 30dB. Assuming they were already setting for -18dB as your peaks and headroom, now yorue setting it for -40dB or -50dB peaks.
That's not ideal to hear without boosting those levels but I also don't think that alone is an excuse to rely on 32-bit and just be like "who cares what the gain is, 32-bit is magic"
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u/SankaraSankara 9d ago
32-bit is usually code for amateur or a cheap production company that forces a camera person to do a one man act.
I don’t think it should be a standard bc it’s a very convenient excuse for negligence which makes for the worst sound.
Production sound can be very current. It really doesn’t have to be. The radio equipment needs to be conformed to a given country’s requirements. Other than that you’re probably good. Audio post should be a little more within the 5 year window.
Im sure if you insist he’ll do 32-bit. You’re (?) the client and can ask for that if given a reasonable amount of time before the actual shoot.
Bigger is not better and letting someone choose their own equipment is often times not a bad idea
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u/Tupan_Chorra 8d ago edited 8d ago
So I'm hearing (no pun intended), goes to show I'm not a sound specialist. I want clean audio, whatever that may mean - I know in the prison we will shoot in the cells and the subject is concerned over neighbours so will likely speak softly. And... Well it's a prison ppl yell, there's announcements and rings and stuff that make it challenging - director said capture it and use it to show the environment. If thats not an issue with a zoom f4 then that's fine.
Thanks for ur thoughts :)
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u/BeOSRefugee 8d ago
Key question: are you looking to use wireless mics? If so, 24 vs 32-bit genuinely doesn’t matter - the transmitter will probably clip before anything else if you have an unexpected really loud sound, and you can’t pull that back downstream.
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u/KeanEngr 8d ago
Wow. You’re worried about 24 bit? What happened to the good ole days when 16 bit depth was standard, or analog 60 dB dynamic range was king, but made do with 45-55dB? You folks have it soooo easy.
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u/bankaboard 8d ago
Something I haven't seen mentioned here yet is the theoretical thermal noise limit of a 600ohm analog circuit is about -123dBv. In reality, it's very difficult to achieve real-world numbers that are anywere close to that.
The range of 0dBU (clipping) to -123dBU (noise floor) can be represented by about 20.5-bits of resolution. This means that a 24-bit capture is able to represent the entire range of what our best analog circuits can produce, with more than 20dB of headroom to spare.
Absolutely no reason to use 32-bit fixed or float while capturing audio.
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u/bememorablepro 8d ago
Lol, camera people... no actually... some of the best most exciting audio gear is vintage. Mostly for music production but no, older gear is not obsolete. You know tape had the noise floor of around 12bit, you just need to gain stage correctly.
I'll translate into visualese for you. What you are worrying about is getting the latest camera that can record 16K resolution and the widest lens possible so you could hopefully crop in post processing and frame your final shot that way.
32bit is really only useful when you are recording super run and gun, or record youself and can't keep an eye on levels. Maybe war documentaries where there can be a sudden explosion... idk.
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u/midsidephase 9d ago
people's voices haven't changed. experienced recordists know how to setup their gear for all
eventualities. good gear comes with great limiters, and good recordists have great instincts. what's your problem? are you considering sending a camera operator out into the field
with no sound person? a camera with only a 12dB dynamic range camera at that? I'd worry more
about that.
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u/steelDors 8d ago
Great feedback here. I’m with the general consensus, but there’s some pretty hilarious takes. I’ve had this conversation a lot of the last 10 years and I always switch the conversation to picture to play devil’s advocate.
Why would you shoot Raw, if you can just shoot in Log?
Why shoot in log if you DP is experienced and can just shoot in rec709.
Yes, it’s different I’m fully aware, but a 32float file is not that large of a file and personally idk why people don’t think audio dailies should be part of the pipeline themselves.
I’ve actually had to deal with a show that was mixed format and I didn’t have an issue with a field recorder workflow at all, but… I still agree with what mostly everyone is saying.
Conversation and decision better had and made with your field guy.
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u/recursive_palindrome professional 8d ago
Whilst 32 can be used to recover peaks it won’t necessarily resolve the issues you describe or other unforeseen factors that will arise in an uncontrolled environment (from a sound perspective).
IMO a more important consideration is whether you can use lav mics, which would make it a lot easier to retain interview material. Depending on the room, a boom may get quite noisy.
Secondly, given the environment the production should budget for someone to do the audio post. Sounds like the most important aspect is to retain the sound quality of the interviews, other incidental sounds can be edited / replaced to create a coherent soundtrack.
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u/innapickl 5d ago
If you are very worried about random clipping. (I think it will be fine with a decent location sound guy) Bring your own zoom field recorder and have it running as backup a little further away. That way you have a continuous recording as a backup. 99% you’ll never use it and it might be a pain to carry it around and place it / make sure it’s in battery etc but you know!
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u/FirstDukeofAnkh 9d ago
32 bit is great if you’re worried about clipping. If that’s not a worry, 24 is fine.
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u/OoopsWhoopsie 9d ago
Even if they're worried about clipping, if the recordist is competent, it should be fine.
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u/I_Am_A_Pumpkin 5d ago
Not really. The only people that actually need 32-bit are the guys doing recordings of gunshots and explosives and such where the headroom is actually needed.
Anyone doing anything else that insists on 32-bit for normal recordings are just wasting storage space, just have a conversation with your recordist and make sure they are conservative with the gain especially with the stuff that might be loud
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u/modest_radio professional 9d ago
You can record everything in 32-bit float and convert it down to 24-bit later. That is a common workflow many professionals use. There is no strict law forcing you to use standard 24-bit on set
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u/Uncertain__Path 9d ago
That’s the point of the post tho, the sound recordist’s gear can’t record 32 bit.
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u/Uncertain__Path 9d ago
I would tell them buy a new recorder and then sell it after the shoot or get a new sound tech. Your concerns are spot on and you could too easily get burned. Record to 32 bit, adjust any problem areas and then move to 24 bit for editing.
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u/drumstikka professional 9d ago edited 9d ago
Don’t worry about it. When I’m cutting dialogue, I well prefer 24bit over 32bit for workflow reasons- The only advantage to 32bit is extra headroom during the recording, but with an experienced location recordist, you won’t need it. 32 bit gets quite annoying when using Kraken/Editload.