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SBretzke

Should recording an Impulse Response during production be as standard as recording room tone?

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As convolution reverbs become increasingly common and affordable, it seems this is where the future of post-sound mixing lies. With that in mind, should production sound mixers be integrating IR recording into their workflow?

 

How many prod. sound mixers out there have already integrated impulse response recording into their workflow on-location, or have ever done it at all?

 

How many post-prod. sound mixers out there wish there were more PSM's doing this? Do you use convolution reverb? Would you use it more if more recordings were provided?

 

From what I've read around the web, it seems like convolution reverb is mostly just being used as a "fix" to match ADR with production dialogue, and not more generally as a standard mixing step (but maybe it's being used more than I realize?). In which case, if the PPSM's don't use it, no reason for the PSM's to bother.

 

To me, it seems that the practice of recording the IR response of a space should be as standard and ubiquitous as recording room tone. Of course, post won't necessarily need to use it, but sometimes the same can be said for half the production dialogue anyway.

 

Assuming you've got a workflow you're comfortable with, recording the IR should take about as long as recording room tone, so you're not taking up an exorbitant amount of time, <2.5 minutes for both IR and room tone (unless, of course, the AD/director/producer isn't even willing to allocate time for room tone, which is a sad reality of many productions).

 

Sure, there are IR libraries, but I would compare a library IR to a library room tone loop: you can generally get away with it, but that doesn't mean it couldn't be much better with an authentic recording from the location.

 

Should PSMs treat IR recording the same way they treat room tone? Maybe my logic is naïve, wrong, or extrapolating too far. Let me know what you think!

 

 

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13 hours ago, SBretzke said:

 

Should PSMs treat IR recording the same way they treat room tone? 

 

 

Yes. And to me (a PSM) that means don’t do it. I don’t record room tone anymore. I just cannot see the point. Every set-up sounds differently, depending on the lights, the people in the room, the position of the boom, and so on. So when do I record it? After every set-up? After many conversations with sound editors, RRM‘s and here, I have learned that post doesn’t need roomtone anymore. They have tools which can automatically find, extract, and loop room tone. And theirs will always match whereas mine will almost never match. 

The only people I know of who need roomtone are picture editors. But unless they specifically ask me for it, I won’t do it. Even if they do ask, I might try to talk them out of it. 

Atmos are different, by the way. When they are interesting, I‘ll record them. 

 

Convolution reverb is similar. You would need to record the IR, when everyone is in the room, incl. the same amount of lights, dolly, etc. for each setup. The rooms we are in often offer a less than desirable acoustic experience. Why do I want to hear that ever again? If they decide to ADR a scene they can easily find a suitable and hopefully nicer reverb than the original one. 

However, I can see that it could help if only a few words are replaced or even just to hide a between two words or whatever. But it would really need to be worth it, as it‘s quite a hassle to record IRs, so I‘m hoping I won’t ever be asked for one. Unless it’s a really unusual space. I don’t know if something like MatchReverb (like match EQ) exists, but if it does it’s probably the more appropriate tool

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Agree with Constantin. I don't remember my last time recording room tone.

Today's post production tools has been much more smart than four - five years ago.

I see an increasing demand for off camera dialogue, rather than room tone.

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"(unless, of course, the AD/director/producer isn't even willing to allocate time for room tone, which is a sad reality of many productions)."

THIS!! 

 

So, forget it...  most of the shows these days don't even try to keep sets quiet, let alone provide a few moments for room tone or anything else..

 

 It's the Wild West.... for me, literally...

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13 minutes ago, afewmoreyears said:

"(unless, of course, the AD/director/producer isn't even willing to allocate time for room tone, which is a sad reality of many productions)."

THIS!! 

 

So, forget it...  most of the shows these days don't even try to keep sets quiet, let alone provide a few moments for room tone or anything else..

 

 It's the Wild West.... for me, literally...

Yep. 

Personally I'd do whatever they (Director) wanted, but they don't know or have the time so I doubt it happens much. I did fill in for someone once on a feature where post audio was on set doing this for each set up. It might of been Jeff. I only did a day or two on that show. Not sure they ever used the tech in post. Maybe J W does. It is an interesting technology.

CrewC 

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I recently did the post production for a short movie where the actors tried to lipsync a pre recorded song on set, which later on was replaced with the studio recording and had to sound like it was recorded on set. Tried a few stock IRs in Altiverb, but nothing matched quite well, so we drove to the location and recorded some IRs. Used the Mkh 8040/30 MS combo, and a balloon (which worked the best). If the studio version of the song would have been recorded with the same location mic (mkh60), the results probably would have been better, but nevertheless I got a lot closer than with any other IR, like 85-90% with eqing. You can probably match it up to 95% if everything is recorded with the same mics, eq'd properly etc.

 

It's true that you will never have the same acoustics without lights, people and other stuff in the room, but honestly you don't want anything noisey while recording IRs and if the room is too reflective you can try molton to damp it.

 

The last time I was the production sound mixer, I recorded IRs after the shoot, because I new I would be doing the post production aswell. Never had a request from other re-recording mixers or sounddesigners tho, sometimes they don't even know what an IR is..


 

 

 

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In sound cutting, esp of sit-down interviews in noisy locations, RT can be useful and I use it if the editor bothers to give it to me.  But that's a case in which the whole scene is playing in a single setup, and neither the mic or the talent move (and in corpo work, the HVAC could be really loud).  If a dramatic scene was being shot in the same location then RT is less useful for all the reasons said--the spatial relationships between mic(s), talent and noise are too fluid for one RT to work all the time.  That said, again, I'll try it in sound cutting if it is there.  But I also acknowledge that esp in recent times it is pretty much impossible to get a production to hold up for even 15 sec after a scene is wrapped, UNLESS the director is an ex-editor!   For RT as well as IRs, I don't think they are hugely important for most decently-managed locations or stages--the more peculiar or present the BG and the space are the more these things could come into play in post.  I will say that one use for an RT is for an editorial temp mix (like cut from your location mix whether or not you have isos too) that is used to "sell" the cut before audio post takes place.

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Instead of doing a proper IR...  How about getting clear slate claps with no BG.  Not as hard for an AD to pull of as after a scene getting crew to settle down for RT.  Altiverb has settings to adjust for different sounding slates.  Denecke- Ambient etc...   Pre slating-- the AD has the control..  After director calls cut...  not so much... You would need just one per setup....  

 

just a thought...

 

j

 

 

 

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I think the real problem in trying to implement this into an "on set" workflow is the time it would take to try to make anybody understand WTF you were even talking about...  If I tried to explain this to an AD I think their head would explode... as for a director, again, good luck...  Interesting concept and tool for our craft though...

 

For a TV show and or a feature you may have to provide a class or a presentation in a pre production meeting to explain what it was you were trying to accomplish.  Not insurmountable, but probably a good idea..

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1 hour ago, Philip Perkins said:

 I will say that one use for an RT is for an editorial temp mix (like cut from your location mix whether or not you have isos too) that is used to "sell" the cut before audio post takes place.

 

Yes exactly, that’s what I meant by „if the editor needs it“, but you put it much better. 

 

1 hour ago, johngooch said:

Instead of doing a proper IR...  How about getting clear slate claps with no BG.  Not as hard for an AD to pull of as after a scene getting crew to settle down for RT.  Altiverb has settings to adjust for different sounding slates.  Denecke- Ambient etc...   

 

 

Have you ever tried this? The IR wouldn’t have any bass content, but maybe that’s even a good thing?

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No Constantin, i have not tried it.  I was speculating the value of using slates-  using slates are part of the software.  So the altiverb designers must have had some practical use for using slates IRs.....  i would think that there is little need for bass content....    

 

 

Few more years...   I think if the request came from higher up the food chain than the mixer, it would be integrated pretty quickly.  I think it is probably no more awkward to explain than explaining why the VFX person who has to walk thru the set with a mirrored orb on a stick at the end of a scene...  They need it- so it gets done.....  

 

j

 

 

 

 

 

 

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I'm surprised about the comments on room tone.

Scenes that are a single shot - not needed

Scenes that are going to have a music score over then - no

Long dialogue scenes with many edits - yes

Scenes where a dominant background sound - yes

Our job is to cover options even if they are not used

 

mike

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1 hour ago, mikewest said:

 

Our job is to cover options even if they are not used

 

mike

 

Yes, but my job is not to waste everyone‘s time. And if I know that post is not going to need it, I won’t record it. 

Yes they need roomtone on scenes with many edits, but they don’t need it from me. They can easily create it themselves and it‘ll sound better, because it was found a few seconds before or after the edit point. Roomtone recorded later is rarelygoing to be a perfect fit and since they have the tech for better tone they won’t use it, and so, if I still record it, I’ll be wasting time. 

 

It‘s different with a dominant background, I would record that, but I always thought that wasn’t considered roomtone, but atmosphere. I will record that, but actual room-tone, I won’t 

 

3 hours ago, johngooch said:

No Constantin, i have not tried it.  I was speculating the value of using slates-  using slates are part of the software.  So the altiverb designers must have had some practical use for using slates IRs.....  i would think that there is little need for bass content.... 

 

 

Shame, I would be genuinely interested in how well that works. And I agree, it would be a workable option if the resulting IR sounds good. I‘d still think that the freq content might be a bit limited, but it could work just fine on speech. 

For a while that’s what I did to get any useable roomtone (before I mostly abandoned it): I‘d ask the director to just pause for a couple of seconds after the slate (or after „set“) before calling „action“. That was usually all post ever needed. 

But most directors would either never do it or forget it after a few takes and to continually remind them gets old very quickly 

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I’ll ask for roomtone but 9 times out of 10 I’m told there is no time. I was on a shoot and the director was previously an editor. I  got the go for RT and rolled and about 5 seconds after rolling the director yells cut and no one moves because they were so confused since roomtone lasts longer than 5 seconds. Director ruined the roomtone and I never asked for it again. 

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9 hours ago, Constantin said:

Yes but 30 seconds is not wasting time and how do you know beforehand that post are not going to need it.

Also is recording audience tracks or sports activity for a production is wasting everyone's time - it's part of your job

mike

 

9 hours ago, Constantin said:

Yes, but my job is not to waste everyone‘s time. And if I know that post is not going to need it, I won’t record it. 

Yes they need roomtone on scenes with many edits, but they don’t need it from me. They can easily create it themselves and it‘ll sound better, because it was found a few seconds before or after the edit point. Roomtone recorded later is rarelygoing to be a perfect fit and since they have the tech for better tone they won’t use it, and so, if I still record it, I’ll be wasting time. 

 

It‘s different with a dominant background, I would record that, but I always thought that wasn’t considered roomtone, but atmosphere. I will record that, but actual room-tone, I won’t 

 

 

Shame, I would be genuinely interested in how well that works. And I agree, it would be a workable option if the resulting IR sounds good. I‘d still think that the freq content might be a bit limited, but it could work just fine on speech. 

For a while that’s what I did to get any useable roomtone (before I mostly abandoned it): I‘d ask the director to just pause for a couple of seconds after the slate (or after „set“) before calling „action“. That was usually all post ever needed. 

But most directors would either never do it or forget it after a few takes and to continually remind them gets old very quickly 

 

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To clarify: when I say roomtone, I mean exactly that. The sound a room has when nobody speaks or moves. This is always indoors. 

The audience in a football stadium to me is called atmosphere. I won’t record the former, but I will the latter. I don’t know if the nomenclature is correct, or universally accepted (judging by this thread it’s not), but it’s what I go by. 

With the atmospheres it very much depends on what it is. On my regular show, I know that post is very good and they have terabytes of sounds in their archives. They don’t need the umpteenth background chatter in a restaurant, but they may need a full surround audience recording in a football stadium. On other shows I may be more cautious and record more of such. I talk to post regularly and ask them for their needs and how they got on with my recordings, so I have a pretty good idea of what they need. 

 

Oh, yes roomtone takes 30 seconds. But getting everyone to quiet down (or wait for the stampede towards the door to subside) can take several minutes. 

 

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A room tone usually gets around 3-5 minutes to set up and record it; not everybody is "ready" when AD calls for room tone. Then, you have to be lucky to get a .30 seconds clean room tone. Wasting 9 to 15 minutes (total) on set for room tone, which the post production not going to use it; it's waste of time really. I am not saying room tone isn't usefull. I am saying post production have much more smart tools these days, espacially in the age of iZotope. Agree with Constantin overall here.

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Yeah there are some "roomtone maker" tools avail now and you will not be surprised to learn that they work about as well as the quality of what they are "fed" allows them to.   To me relying on tools like that is the same as relying on noise reduction or ADR or my personal fave; "there will be loud music under all this" to make an audio cut work.  Better to do things right from the get go and save the tools for when you really need them, instead of assuming that an artifact-free cut w/ minimal BG noise can be made at the push of a button.  I invoke Berger's Law: "Those tools work the best when you need them the least".

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Ok, being old school I like to deliver and not presume.

Yep post can do a lot of things but I do not know who is doing it and what they need or do not need.

Also with sound fx I like to record them and they add to my really large library.

 

mike

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I'm an editor, and yes, I DO want roomtone. (And want to know where it is.)

My work is mostly doc style.

I often need 5 seconds to cover / fix an ugly cut, and almost never that can be found in the footage close to the takes used. (I can imagine that's different with drama, but I don't do that.)

I don't buy the time it takes on set. Do you know how much time it takes for me (and the director if he's sitting in.) to go to hours of footage to find a tiny piece where everyone shuts up? And then have to loop 4 frames to get 'something' ? It's annoying at least.

I don't have a large library of this kind of stuff, I just need to be able to add a pause during spoken text, add tone to a cutaway with no dialogue, that kind of stuff.

For what it's worth...

Bouke

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I don't buy the time it takes on set.

 

Fair enough....  Were with you in theory, believe me.....maybe you can argue with them on set about it for all of us (perhaps by phone).....   The First AD and the Director run the set... when they say no, that means no....

 

   Just like the throngs of safety training WE are required to take, that they are NOT required to take,  maybe the AD and the Director need to get this memo from you as well.. (along with all the safety stuff).. Seems there's a lot of memos they do not get on their end.

   I am all for taking the few seconds to do it.... but, they have to be onboard... my days of demanding things on set are long gone.  I will say something once... and thats it.   As I LOVE to say.... "it's not my movie"

 

Funny though they will wait 20 minutes for a light to be set... This is simply the way it is on many sets these days, not all, but many.

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1 hour ago, afewmoreyears said:

I am all for taking the few seconds to do it.... but, they have to be onboard... my days of demanding things on set are long gone.

 

Magic word: "Onboard". 

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The real world includes Director, AD and DP knowing they have X minutes to get the scene and the time it takes expands to fill 'X'. "Check the gate!" comes at 12:59 and at 13:00 the production is looking at meal penalties. Even forewarned that RT is necessary 100 x $7.50 means the AD will say, "Sorry. That's lunch." Happens every time.

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