Stereo Microphones - use scenarios and solutions

O

OldCorpse

Rockin the Boat
I am looking for a solution to the following: I need to record ambient/environmental sounds for narrative pieces (in the scene: traffic, crowds, machinery, weather, waves etc.). The idea being that I want to do it simultaneously with the dialogue and/or video, as sometimes you either don't have the option to come back to record environmental sounds, or by the time you come back, the soundscape has changed completely compared to what you've filmed, so the visual doesn't match. An additional minor consideration is that "discrete" is a bonus, as sometimes you don't want to draw attention to yourself when working more informally.

I considered just general omni mics, but aren't stereo mics recommended for such applications? I have the DR-70D which has a pair of inbuilt omnis, but the form factor is awkward and it's not the same thing as xy stereo mics. My next thought was something that perhaps incorporated a recorder, that way you can be more discrete and don't have the drawback of wires and additional gear - something along the lines of a zoom h4n, or a tascam dr-22wl or 44wl. Or maybe the whole idea of "x/y stereo" for what I want is pointless, and one may as well go with something like the tascam dr-40.

I'm a bit lost here. What do you recommend?

Btw., just to head off any derails: yes, I know about sound in post where you're supposed to re-create all sound from scratch (or libraries) to match scenes, with dedicated tracks for all sound sources etc. This is not this kind of production - it's a "quick and dirty" where the environmental sounds are all recorded live and packed on one track - we're talking tight budget production sound, so pleased don't recommend doing all sound only in post.

Oh, I just realized, I also have the zoom h1 which has x/y stereo mics, but I assumed that the mics on it are trash, so I'd need something better(?).
 
The very compact Sony PCM-M10 recorder has fairly good omni mics built-in to it, but if you don't want to buy anything the mics in your Zoom H1 aren't bad either. ( I sold my H1 because I could not stand the fiddly switches and the very creaky build-quality of the H1, but I always thought the mics were pretty good )
 
Dear lord no! I'll use the collected ambient sounds ANYTIME. Provided they sound like what you want it to sound like.
I have a vast SFX library and using a stereo recorder on-site will absolutely work just fine. That's all the people who made those libraries did.
Like I said - it just comes down to "do you like that ambient track you recorded? Or would you prefer to hear something different?"

I have a bunch of different mics and recorders, but you know what I use for this most often? A $90 Tascam DR-05.
I kid you not. It gives me great captures. Great stereo field imaging too. I can't say enough good things about that silly cheap little bastard.

I don;t like Zooms. All of the sub-$400 ones all sound so processed to me. The DR-05 is FAR more neutral and natural.
 
Yes, I have to agree with @DPStewart.
Trying to record ambient sounds CONCURRENT with the principal shooting is an ABYSMAL idea. It is easily the worst idea we have encountered so far in 2016. But it is only mid-April.

Seriously, trying to shoot while recording dialog in a space with significant ambient sounds makes your dialog tracks significantly lower quality than you probably want. And trying to record ambient sounds WHILE shooting just piles on additional problems that turns the exercise strongly negative cost/benefit ratio.

And, as a separate issue, depending on WHAT sounds you are going for, and WHERE you are trying to capture them, a co-incident stereo microphone MAY be the ideal solution, but it could also yield much worse results than using a spaced pair of mics. It is very difficult to make a blanket statement "this is good / this is bad" for such a generic question.
 
Thank you everyone, some food for thought, indeed. As to "ambient sounds CONCURRENT with the principal shooting" being the worst idea - I'm unimpressed as I've read the statement, but have not seen anything backing it up, so its utility is very limited to me in which case thanks... I guess. But then again, I'm a practical fellow, so unless I see cogent reasons stated, I'll just have to experience it on my own. Too often I've seen things confidently asserted, which transpire to be balderdash, so I'll keep looking for evidence not assertions.
 
If you have enough time in post-production mixing, and you are lucky, sure, you could do it.
The "evidence" is now long it will take to get the mix the way you want it.
No, it's not impossible, it is just remarkably more difficult to the point where most people would prefer the conventional approach.
I wish you luck.
 
I've said it before and I wasn't going to again but you asked...

IF your film takes place on a low budget film set then what you record is appropriate for the track and go for it. You said narrative film and narrative films are almost never shot in a location that is what that location is supposed to be so what you are recording is actually fighting the "world" you are trying to create.

Nobody but low budget filmmakers use "all from libraries". Yes you are going to pull some sounds from libraries that you just can't get, but a very large portion of sounds used in films with budgets is recorded or created for that film.

On a practical level assuming that the sounds at the location are the ones you want it is best to record at a different time because sets are noisy places. Either your not shooting and crew is working or you are shooting and actors are working. For B roll it makes some sense, and if you have built in enough quiet time in the shoot maybe, but then you are wasting shoot time and that is usually not an option. I have been on gigs where I was recording SFX while they were shooting and except for MOS shots where people were told to keep silent it was usually a waste. What I usually did was get as far away from the noise as possible and record ambiences and then try to catch specifics like say a car sound once they were through with it, and as far away from the set as I could go.

It is just rare that you can get what you need with out a lot of sound pollution. IF you can then go for it.

I was told once and as a generalization it's not bad, that larger than your head record stereo smaller record mono. The hand recorder is a good option. Quick and available and decent quality.

So other than the issue of getting clean sounds and that what you are recording may not fit with what the shot (in the world of the film) should sound like the only other issue is if you don't have someone separately doing the recording you are recording with out monitoring and that is not a recommended thing.

I always want to record as much as I can in locations because as you said you may not be able to get back. I tend to use sounds from the location as the basic track IF they actually match where the scene should be taking place. I know a lot of no budget filmmakers get into some weird mode where they look at the location as being what the location is. That is a trap that wastes a lot of time and/or money and usually gives them a "no-budget" sound, that they then slather some music on. It's a style. I'm not particularly fond of that style but there are folks who work to create it so?

I do a lot of post work but then that is what I mostly do. I hate the empty echoey, music slather no-budget sound, it just bugs me. It's not "wrong" and if that is what you are going for forget the post sound work because it probably won't help you get there. I like the control of sound post. I can put in the door sound that the story wants rather than being stuck with whatever the set sounded like. There is no reasonable way, with out a trust fund, to do the kind of detailed sound work a major feature does on a low budget film and break even. But you don't have to. I use 80-90% of the production sound. For one thing it has all the cloth sound in it and that is a PITA to cover, and adds so much. I do almost no real Foley. I will do "wild Foley" which is a bit of an oxymoron but is basically what should be done on a Foley stage but done in the field and then edited to sync. I record as much stuff as I can because even if I don't use it I will have it in my personal library and can maybe use it later. I add layers of backgrounds to set the scene in the world it needs to be in. The side benefit is that if you use hardly any SFX every one you use will stand out as phony. If you do decent coverage with BG's etc. then specific SFX that you want to add fit in a lot better.

Those are the reasons I do post and they may not fit what you want to do at all so just giving you the other side.
 
Thanks guys, for the detailed answers! That's the kind of stuff that's super valuable and makes this place awesome... and you guys are saints for putting up with clueless newbie questions. To elaborate. Here are the situations I'm thinking about. I have to steal a few locations - or not even steal - where we're following two characters walking along a street, into a mall etc. My idea was that since you are going to see the traffic and noise generating visible sources (passing people, dogs barking etc.), why not have somebody nearby who is equipped with a little recorder gathering up all that environmental sound. Because the dialogue sound is going to be more closely mic'ed with a couple of lavs, I wanted the option of having as much isolation between the dialogue and the environment, so that I can then globally raise/lower the level of one vs another. Had I tried to record both on the same mic, I'd be stuck with whatever levels of dialogue and environment are. Now, there will be occasions when stuff can go wonky, an unusually disruptive environmental sound that is unacceptable (the classic passing helicopter we don't see but hear at ear splitting level etc.), at which point that part goes to heck, but on the whole you can get usable stuff. I wasn't thinking of using this on a set where environmental sounds are not what I'd be focusing on (or in the case of room tone would be acquired with the same mic as used for dialogue for the most part). I'm talking almost run'n'gun type footage and sound - stealing locations, or quick stuff. I understand that bigger budget productions are a different world, I'm talking microbudget.
 
Well what I would see as a possible gotcha is that those recordings won't be in phase and it may not even be possible to get them in phase since the relationship between the mic and the sounds will be constantly changing. SO... mixing them would give you a kind of classic 60's R&R phase shifter sound on the BG's. Depending on the film that might actually be really cool, but it won't be controllable.

Sounds not recorded at the same time won't have this problem.

Two "truths" though that might help you. Pretty much nothing sounds like you think it does. Partly because there is such a big emotional component to how we hear. So having the "real" sound is 99.99% unneeded. It's good for a reference but... In your proposed shot traffic of about the right density will fit for everything but a close car by. If you go to a street and sit for a bit you should get a bunch of by's and you can use one of those to cover a close by. Most of the time you can use just about any by and it will sound fine, because the audience knows cars all sound different and unless the sound is wildly inappropriate they will assume the sound is just that cars particular sound and forget it.

The other "truth is that One thing sounds like one thing. Two sound like two. But three sound like a "bunch". Over three and you start to get into mud. It's a lot like music up to two are notes three is a chord. You can push it out to four but harmonies get complicated and over four is just weird or one is an octave doubling. So you don't need to track everything. You need to track what is Close, CU and ECU, everything else is just BG (unless it does something to make it a focus point).

how this relates is that you can shoot with a thin BG track and it doesn't take a nightmare of work to build it up to a decently full sound. For Q&D you could often get away with just another similar but full BG but you would want it at a different time so you don't get weird phase issues.

You might get away with having the SFX recordist pointed in a different direction and separated a bit so they are catching essentially the same sound but it's different enough to not phase out on you. That "might" work.

As to stealing sounds, for your stolen shots ;~). If you sling a recorder over your shoulder and hold a mic in a dead cat and try to record in public every third person will walk up and into the mic ask if you are recording. "Not any more" is funny once. However if you have the same set up except you hook the mic in your pack and point it behind you, switch to earbuds and look at your phone you become invisible.

With a smaller rig you are already less visible and with a hand held you can even look at it just don't visually pay any attention to what you are trying to record and everyone will think you are listening to music and poof you disappear.

The phone is great though. You can do just about anything while pretending to listen to someone on the other end and be invisible. Probably can't shoot much that way, though there are things that let you stream a viewer to an iPad so? But for sound you don't have to look at what you are recording. And with the mic pointing backward I have gotten very close to conversations in large public spaces that I never could have gotten close to, with out getting punched. You are obviously ignoring them so... BTW this also works with regular headphones IF you slide it so one ear is off. Everyone thinks you are just taking a break and they may look closer they will not come up to you and start asking questions.
 
OldCorpse said:
As to "ambient sounds CONCURRENT with the principal shooting" being the worst idea - I'm unimpressed as I've read the statement, but have not seen anything backing it up, so its utility is very limited to me in which case thanks... I guess. But then again, I'm a practical fellow, so unless I see cogent reasons stated, I'll just have to experience it on my own.
Click to expand...

Easy enough. Try it and find out why. Because Richard is telling you the truth.

As to why it's the truth, think about what happens when you make a cut. Say your principle actor is done with a line and you plan to make a cut at that point. When you recorded him, a truck was coming up behind him. So you make your cut, and that truck just miraculously vanishes. How will you deal with this discontinuous sound?

The only way I can see this can possibly work is if you commit to a big long continuous take. So if you want to cut back and forth between actors, you've got to use multiple cameras. Which will probably be a lighting and blocking headache, but how else you can pull something like this off?

Once you have that big long take in the can, when you get to post all kinds of things happen. You'll get all kinds of bleed from the two lavs. If you try to dip levels on the inactive lav while the other actor talks, you'll find that your ambient sound shifts with it. The guy closest to the wall picks up more wall reflections than the guy closer to the street. Just the way it is. So, if you decide then to leave both mics open all the time, you open the door to phase issues. Not to mention the interesting issues you get when you try to mix the stereo recorded ambient, made at a third location (no matter how close to the two lavs, it's a different perspective). And this third ambient recording will undoubtedly catch some bleed from the actors, which makes mixing just that much more painful if you can do it at all.

You don't have to blindly believe that there's a reason Hollywood separates the recording of dialog from everything else. You do this big long take as an experiment, you might learn why. Sometimes that's the best way to learn something -- try it and see.
 
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