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Offline DSatz

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Musings on shotguns vs rifles
« on: May 19, 2021, 06:14:36 PM »
Hi. I haven't had any training with firearms since a few minutes spent on a rifle range at a YMCA camp 60 years ago by now. I've long used the term "shotgun microphone" while being aware that in the UK, "rifle microphone" was the more common usage, at least up through the 1970s and 80s (not sure about since then). I'd heard the expression "shotgun approach" but ironically, didn't look up what it meant--in other words, I used a kind of shotgun approach toward understanding what a "shotgun approach" was.

Today I was listening to an audio book about human psychology (Daniel Kahneman's Thinking, Fast and Slow). It uses the term "shotgun" in a way that depends on the reader's awareness that this type of firearm suffers from a distinct lack of accuracy. I found that startling at first--then looked up "shotgun" on Wikipedia and found it amusing--since I've long been aware of the mistaken beliefs that many people seem to have about shotgun microphones. And now I think that the term is actually rather apt, not just visually. Shotguns are well known (in contrast to rifles) for the dispersion of the pellets that they deliver. They can't generally hit a target in a precise or focused manner, all the more so if the target is at any significant distance.

So part of the problem where microphones are concerned seems to be that people see shotguns, but imagine that they're rifles--maybe even some kind of computer-controlled super-rifle that exists only in the movies.

The metaphor breaks down after that, since like any other microphones, shotgun mikes respond to the sound field that exists at their location, not the one where you "aim" them. The sound has to come to them--and by the time that happens, if they're at all distant from the sound sources in a reverberant space, plenty of other sound is reaching them as well, which they aren't well equipped to cope with. Most people chronically underestimate (by a lot!) the amount of reflected sound that almost any non-close-up microphone will pick up in most live recording situations--and don't realize how weird and sucky the off-axis response of most shotgun microphones is beyond a narrow angle in the front.

In other words, microphones are of course receivers rather than sources--but people get fooled psychologically by their shape into thinking of them as being active only in the direction that they're pointed--which is far from being the fact.

--best regards
« Last Edit: May 19, 2021, 11:16:57 PM by DSatz »
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Offline crackmc

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Re: Musings on shotguns vs rifles
« Reply #1 on: May 19, 2021, 11:11:06 PM »
i often use the rifle/shotgun analogy when my non-taper friends ask me why i don't use them

i don't really consider the inaccuracy element so much, but in a nutshell i describe it like: shotguns are the perfect firearm for a very specific range of target...and i'm often not within that specific range from my target

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Offline voltronic

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Re: Musings on shotguns vs rifles
« Reply #2 on: May 20, 2021, 06:32:03 AM »
I always assumed the "shotgun microphone" term was given more for similarity in appearance than function.

Firearms sidebar: While most rifles should have greater accuracy at longer ranges than most shotguns, I disagree with the idea that shotguns are inherently inaccurate. You and the sources you are reading may also be assuming that a spray of pellets is all they can do, but you're forgetting about large, single rounds (slugs). I have seen 12 gauge slugs be accurate beyond 50 yards. You can also buy rifled barrels if this is something you do regularly, making it effectively a large-bore rifle in all respects. Then there is the common myth that you "don't have to aim" a shotgun when firing pellets of buckshot or birdshot. I can tell you as someone who does clay pigeon shooting that careful aim is absolutely required. Modern shotguns have come a very long way from the old short-range blunderbuss. Then there is the complex discussion about different barrel chokes and how they affect dispersion at various distances... you get the point.

Actually the more I think about it, chokes are a decent analogy for the directional nature of how the type of microphone we are discussing picks up. Take a look at these resources, especially the graphic from the first link which I'm including here for convenience. In my mind, a longer shotgun (mic) with increased diaphragm venting space to the rear is analogous to a full choke that has a more constricted pattern at shorter ranges.

https://1source.basspro.com/news-tips/hunting-gear/7692/guide-shotgun-choke-tubes

https://www.rem870.com/2012/05/06/shotgun-chokes-explained-cylinder-improved-cylinder-modified-full/



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Offline Gutbucket

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Re: Musings on shotguns vs rifles
« Reply #3 on: May 20, 2021, 12:06:28 PM »
I find it helpful to flip the primary understanding of the role of longish interference tube microphones away from thinking of them in terms of on-axis focus and "reach", instead thinking about them in terms of off-axis attenuation, the behavior of that attenuation, how that behavior does or doesn't suit what is being recorded, and how it might fit with whatever else is being recorded.

Rather than being about "focus", it's primarily about "rejection" and the qualities of that rejection. 

Shotgun mics are less sensitive to off-axis sound, yet they cannot attenuate off-axis sound completely and what is not attenuated tends to sound not as good as what one would get from a well-behaved directional microphone that does not use a longish interference tube.  It boils down to a trade-off between quantity and quality - Is the increased off-axis rejection worth the less natural off-axis pickup that comes along with it?  

For some applications the answer is an easy yes, and shotgun mics exist primarily to fill such roles.

Does it suit what is being recorded?-
For concert recording the answer is not an obvious and easy yes.  Our microphones are acoustically distant from the source so the sound-field at the recording position tends to be dominated by off-axis sound arriving from all directions.  The further back we are, the less dominant direct-arriving sound will be in the sound-field which exists at the recording position, making good off-axis behavior increasingly important.  And there lies a conundrum- off-axis attenuation becomes desirable, yet good behavior of that attenuation becomes increasingly important at the same time.  Because of this, the most straight-forward solution to the problem is to use a pair of directional mics that have good off-axis behavior - one of the important qualities which defining good "taper mics" IMO.  If recording using a single stereo pair at a significant distance indoors, I would choose good super/hypercardioids over shotgun mics.  My answer to the question above would be- "No, the increased off-axis rejection is not worth the less natural off-axis pickup that comes along with it, because the bad behavior is too audible and objectionable."

How it might fit with whatever else is being recorded-
If running additional mics, the answer becomes "Maybe". Bad off-axis behavior is not problematic if it isn't audible. Use in a mix with other channels that serve to mask audibility the off-axis problems can work, but only if there is sufficient difference between the positive aspects of what the shotgun(s) contribute to the mix and the level at which their problems become masked by the other channels. And there is not a whole lot of wiggle room there.  A quality super/hyper with better off-axis behavior may still work better.  But in the modern era when we can record each channel separately and adjust the mix by ear afterward, we at least gain the ability to tweak the balance within the wiggle room we have available.  It has a better chance of working at least.

Even without the ability to tweak it afterwards, the once popular GratefulDead section recording method of using pair of shotguns in combination with a single omni, mixed from 3 down to 2 channels ahead of the recorder was a useful technique. Besides extending low-frequency sensitivity for better bass, the good off-axis behavior of the omni served to mask the not-so-good off axis behavior of the shotguns.


Possible exception for good behavior-
I'd love to try Schopes SuperCMITs but they are well out of reach cost-wise. They have the unusual combination of both increased off-axis attenuation and better behavior of that off-axis attenuation in comparison to other shotguns, achieved by leveraging DSP processing within the microphone in addition to being of Schoeps quality with respect to their non-DSP'd off-axis behavior. The reason I'd like try them is totally rooted in their better off-axis behavior, both in terms of  quantity and quality.  And yet, if I ever did have the opportunity, I wouldn't use them as a single stereo pair, most certainly recording additional channels along with them to provide the ability to make the best of things in addition to the ability to listen to them on their own to see how well they might work alone.

As always, knowledge about how these things work, along with trying things out and listening for what works and what doesn't in practice is key.  That's the case for all forms of recording, but especially so for concert taper recording which tends to be atypical with respect to other types of recording.
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Offline morst

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Re: Musings on shotguns vs rifles
« Reply #4 on: May 20, 2021, 04:51:50 PM »
Then there is the common myth that you "don't have to aim" a shotgun when firing pellets of buckshot or birdshot.
To be glib, you aim a rifle, you point a shotgun.

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Re: Musings on shotguns vs rifles
« Reply #5 on: May 20, 2021, 07:31:43 PM »
Then there is the common myth that you "don't have to aim" a shotgun when firing pellets of buckshot or birdshot.
To be glib, you aim a rifle, you point a shotgun.
That depends on what you are shooting at Morst. For flying birds, yes you point. But for things like turkey hunting you have to aim, at the head. You generally don't shoot turkeys flying unless you have done something wrong in your hunt. I have shotgun for turkey hunting with fiber optic sights and an extra full choke that you definitely have to aim to hit the small head of the turkey. Actually I missed one last week that started running off on me, tried to quickly point the gun instead of aiming and missed him.

Offline DSatz

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Re: Musings on shotguns vs rifles
« Reply #6 on: May 21, 2021, 03:52:41 PM »
voltronic, thanks. The main place I went to read up on shotguns was Wikipedia. The article there mentions that a single slug is an option, and it also describes the kind of choke that you described.

But I came away with the impression that those two techniques for achieving greater range and accuracy were "outside the mainstream" as far as the general use of shotguns is concerned--that the first thing that the term "shotgun" brings to mind for most people familiar with them is with the type of, I guess it would be ammunition, that consists of multiple pellets that diverge somewhat as they're fired. Do you think I was wrong to infer that?

--best regards
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Offline EmRR

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Re: Musings on shotguns vs rifles
« Reply #7 on: May 21, 2021, 04:16:58 PM »
I'll add the places my KMR81's have worked out best have been pretty close, as when used similarly to boom mics capturing dialog right off camera.  Seems counterintuitive to the general perception of purpose.   The times I've put them into a larger mic array at distance, they give one version of a particular 'focus', but it's not very natural.  I can maybe get a bit more vocal intelligibility out of an array with a PAS shotgun in a swim sounding room, but there's a definite limit of usefulness.  It seems to work better to have an ambisonic array or dual mid side array that can be steered in post to find the best focus. 

The sound of a pump shotgun being armed nearby is probably the most terrifying to an intruder, as you don't need much of a clue in the dark to hit a target.  You will need more drywall work though......
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Offline Gutbucket

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Re: Musings on shotguns vs rifles
« Reply #8 on: May 21, 2021, 05:20:36 PM »
^
Thanks for posting about your experience using them in that way.

Agreed on the greater value of the ability to tweak directional alignment in post with high precision while listening.   Although the analogy breaks down right out of the gate because sound is not projectile like, it strikes me that the comparison of pointing (shotguns) verses aiming (rifles) made earlier is analogous to visual pointing alignment of microphones during setup verses audible aiming of ambisonics or dual M/S in post.  Other than providing a direct-listening control loop, that also provides as much time as one wants before pulling the trigger - which may be both blessing and curse.
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Offline voltronic

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Re: Musings on shotguns vs rifles
« Reply #9 on: May 21, 2021, 08:04:33 PM »
voltronic, thanks. The main place I went to read up on shotguns was Wikipedia. The article there mentions that a single slug is an option, and it also describes the kind of choke that you described.

But I came away with the impression that those two techniques for achieving greater range and accuracy were "outside the mainstream" as far as the general use of shotguns is concerned--that the first thing that the term "shotgun" brings to mind for most people familiar with them is with the type of, I guess it would be ammunition, that consists of multiple pellets that diverge somewhat as they're fired. Do you think I was wrong to infer that?

--best regards

I wasn't trying to rain on your parade. And yes, what most people think of when they think of a shotgun is firing buckshot - the 9 or so large pellets that blow a hole through a door or a zombie or what have you in movies. I only was trying to correct one of the common hollywood gun myths that you don't have to aim or even sight down the barrel with proper form - people get hurt in the real world trying to operate a shotgun that way.

Slugs are not that exotic, but are very expensive (even before ammo prices skyrocketed with the pandemic). Choke tubes are extremely common though; any modern shotgun sold today comes with at least two. It's all about dialing in the amount of shot constriction you want at a certain range, and that was where I was thinking of the connection to shotgun microphones. The choke constriction is analogous to the length of the interference tube. Gutbucket has a better explanation though (as he usually does).
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Offline morst

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Re: Musings on shotguns vs rifles
« Reply #10 on: May 22, 2021, 02:42:28 PM »
the common hollywood gun myths that you don't have to aim or even sight down the barrel with proper form
Oh yeah, one more bit I learned in high school gun club was you aim a rifle with one eye shut, but you keep both eyes open when shooting trap & skeet with a shotgun, because you need depth perception.
Tangentially, I learned when i worked in a jewelry store that when you use a magnifying loupe, you should keep both eyes open so you don't mess up half your face squinting all the time.

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Re: Musings on shotguns vs rifles
« Reply #11 on: May 22, 2021, 07:31:46 PM »
the common hollywood gun myths that you don't have to aim or even sight down the barrel with proper form
Oh yeah, one more bit I learned in high school gun club was you aim a rifle with one eye shut, but you keep both eyes open when shooting trap & skeet with a shotgun, because you need depth perception.
Tangentially, I learned when i worked in a jewelry store that when you use a magnifying loupe, you should keep both eyes open so you don't mess up half your face squinting all the time.

I actually tend to shoot clays with just one eye open as though I am using a rifle. It's the wrong way, but it's how I started shooting, and I tend to score quite well. I can't believe I never thought about the depth perception aspect though, and none of my instructors ever mentioned that.
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Offline morst

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Re: Musings on shotguns vs rifles
« Reply #12 on: May 22, 2021, 10:32:44 PM »
you've been shooting the clays in mono!

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Re: Musings on shotguns vs rifles
« Reply #13 on: May 23, 2021, 01:11:47 PM »
The whole notion of shotguns having wide dispersion, even with bird shot, is vastly over exaggerated in the public mindset.  "You don't even have to aim" and that sort of nonsense.  Yes, there is dispersion to a certain degree when using bird/buck shot, but go to a range and try it out on cardboard targets and most people would be shocked at how tight the dispersion is at the type of home defense distances they have in mind.

That said, a shotgun is one of the most versatile guns a person can have.  I just can't help but address the widespread (no pun intended) misconception about how much the shot disperses. 
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Offline DSatz

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Re: Musings on shotguns vs rifles
« Reply #14 on: May 23, 2021, 02:05:44 PM »
heathen and voltronic, many thanks. That's pretty much what I'm trying to ascertain--the reality and (or perhaps, versus) the perceptions other people have about this type of firearm. The "segregation by lifestyle" in this country is so extreme that, just as I know only one person who voted for Donald Trump (that being my former mother-in-law in Texas, who is now in an assisted living facility), I don't personally know any gun owners. But I felt pretty sure that on this forum there would be people who could answer my questions.

I mostly didn't intend to talk much about microphone use, but of course "shotgun" microphones can be very useful for muffling* other, competing sounds that come from off-axis, when you're trying to pick up a sound source that's exclusively (or nearly so) on-axis. That's why their use can make perfect sense outdoors, or even indoors sometimes, to compensate for having to use a somewhat greater distance (i.e. just outside the film or video frame) than you would ideally choose to place a cardioid or supercardioid.

But to use them for picking up a sound source at a considerable distance in a reverberant space, when the same sound that's arriving on-axis is also arriving from many other angles in comparable amounts--they're just not designed for that (no microphone is), and they generally do poorly at it. Their extremely irregular off-axis response merges in with their on-axis response when that happens. (The ear/brain tends to integrate early reflections with the first-arriving sound for up to about 20 mS.)

If anyone gets a chance to watch a film or video being made, note how much trouble and effort a competent boom operator goes to, to keep the talent within a VERY narrow range of angles in front of a shotgun mike on a boom. That's not just for the sake of maximum sensitivity or even a "dry" pickup--it's also to keep the sound from the "talent" from getting in to the sides of the mike, which will color the voice or other sound in a way that is nearly impossible to filter out.

_____________
* edited later to add footnote: I say "muffling" rather than "suppressing" because an interference tube takes effect only above a certain frequency which depends on its length. Shotgun microphones are designed for intelligibility of speech pickup, which is largely a matter of the region above 1500-2000 Hz. To have narrow patterns for music including low frequencies, they would need to be 20 feet long or thereabouts. The only way around this limitation so far is for the microphone to use multiple capsules and fancy methods of combining their signals. A few manufacturers offer this, notably Sanken and Schoeps. But such microphones are extremely expensive and have operational peculiarities that the user has to work within; they aren't the all-purpose solutions that one might imagine them to be.
« Last Edit: May 24, 2021, 12:11:13 PM by DSatz »
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Offline tim in jersey

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Re: Musings on shotguns vs rifles
« Reply #15 on: May 23, 2021, 08:24:17 PM »
The whole notion of shotguns having wide dispersion, even with bird shot, is vastly over exaggerated in the public mindset.  "You don't even have to aim" and that sort of nonsense.  Yes, there is dispersion to a certain degree when using bird/buck shot, but go to a range and try it out on cardboard targets and most people would be shocked at how tight the dispersion is at the type of home defense distances they have in mind.

That said, a shotgun is one of the most versatile guns a person can have.  I just can't help but address the widespread (no pun intended) misconception about how much the shot disperses.

Took Mom In Jersey to the shooting range recently. Almost 80, and she's *scary* accurate with the .22 target pistol my dad gave her as a wedding present...

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Re: Musings on shotguns vs rifles
« Reply #16 on: May 24, 2021, 06:10:03 AM »
The whole notion of shotguns having wide dispersion, even with bird shot, is vastly over exaggerated in the public mindset.  "You don't even have to aim" and that sort of nonsense.  Yes, there is dispersion to a certain degree when using bird/buck shot, but go to a range and try it out on cardboard targets and most people would be shocked at how tight the dispersion is at the type of home defense distances they have in mind.

That said, a shotgun is one of the most versatile guns a person can have.  I just can't help but address the widespread (no pun intended) misconception about how much the shot disperses.

Thanks; that's exactly what I was trying to get across in my earlier post, and you said it more succinctly.
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Offline lsd2525

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Re: Musings on shotguns vs rifles
« Reply #17 on: May 24, 2021, 09:53:58 AM »
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Offline datbrad

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Re: Musings on shotguns vs rifles
« Reply #18 on: May 24, 2021, 03:07:04 PM »
One of the highlights of my GD taping days was a discussion me and my cohort Chet had with Owsley in the taping section 1st night Boston Garden'93 about my Nak CP4s + a center CP1. He was patching his Greenpeace buddy's D6 out of different rigs throughout the tour and all the tapers that night shunned him because they didn't know who it was. Chet called him over and when he saw my rig he was skeptical of the 3 mic method and went on for 15 min about the stereo purity of a pair of cards and how wrong it was to mix 3 mics. Well, he ended up patching with us anyway and he came back every night after that, so he must have not been too horrified, lol. The only time in my life I actually smiled while getting lectured about my misguided ways.
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Offline DSatz

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Re: Musings on shotguns vs rifles
« Reply #19 on: May 24, 2021, 07:56:50 PM »
Well, he did have a point. Any approach toward recording is based on some particular type of playback system that it's suitable for. Historically the two main schools of thought about stereo were the one from Blumlein (two directional, coincident microphones -> two loudspeakers) and the one from AT&T Bell Labs (many microphones spaced apart -> an equal number of speakers).

Three microphones/recording channels/loudspeakers is just the Bell Labs approach stripped down to a certain compromise between effectiveness and effort/cost. But if three is better than two, then four is better than three, and so on--the more discrete channels you have (complete from microphone through recording through playback via a separate loudspeaker for each), the closer you can come to recreating the original sound waveforms of the performance.

Cutting the Bell Labs approach down even further, to two channels, leaves a notorious "hole in the middle" if the sound source is wide, such as a symphony orchestra. The technique of adding a center mike originated in an attempt to mitigate that problem. But it's only somewhat effective, and it comes at a cost of other qualities about the recording unless you are very practiced at the technique, and also rather lucky. Any time you mix signals from separate microphones into one recording/playback channel, you produce cancellations and colorations of sound that can't be straightened out by any form of subsequent processing, unless your microphones are picking up mutually-exclusive sound sources or nearly so (see the "three-to-one" rule).*

In most cases if you're limited to two playback channels then it's better, in my opinion, to give up the Bell Labs approach entirely, and use either some variant of the EMI/Blumlein approach (e.g. ORTF), or go over to a more recently developed alternative such as sphere stereo recording, IF you're sure that some representation of the original sound is what you want to capture. Otherwise multi-mike, multi-track, reverb and EQ, and create your own original project from the ingredients that the musicians provide.

_______________
* I attended (via Zoom) a very interesting historical presentation Saturday night by someone who actually went to Decca years ago, interviewed engineers, and got access to the session logs from when the "Decca Tree" was supposedly used for stereo LP recordings. It turns out that the actual setups varied considerably. Many of the later recordings so praised by certain audiophiles as classic, must-have LPs were in fact not made with the Decca Tree method at all--and that much of the time when it was used, baffles were inserted among the three microphones in an attempt to increase the separation among the channels, and there was spot miking as well. He showed a fair number of session photos. I was rather shocked; I had to unlearn and relearn this chunk of recording history.
« Last Edit: May 26, 2021, 04:42:55 AM by DSatz »
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Offline kindms

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Re: Musings on shotguns vs rifles
« Reply #20 on: May 25, 2021, 07:01:10 PM »
I'll add the places my KMR81's have worked out best have been pretty close, as when used similarly to boom mics capturing dialog right off camera.  Seems counterintuitive to the general perception of purpose.   The times I've put them into a larger mic array at distance, they give one version of a particular 'focus', but it's not very natural.  I can maybe get a bit more vocal intelligibility out of an array with a PAS shotgun in a swim sounding room, but there's a definite limit of usefulness.  It seems to work better to have an ambisonic array or dual mid side array that can be steered in post to find the best focus. 

The sound of a pump shotgun being armed nearby is probably the most terrifying to an intruder, as you don't need much of a clue in the dark to hit a target.  You will need more drywall work though......

https://www.youtube.com/watch?v=CiHHgjaR0TI

this was eye opening. you better be sure there is NOTHING you love behind or anywhere near someone you are shooting at inside or outside your home. this guy shows regular loads going through 2 internal walls and the external wall.
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Offline voltronic

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Re: Musings on shotguns vs rifles
« Reply #21 on: May 25, 2021, 10:10:41 PM »
I'll add the places my KMR81's have worked out best have been pretty close, as when used similarly to boom mics capturing dialog right off camera.  Seems counterintuitive to the general perception of purpose.   The times I've put them into a larger mic array at distance, they give one version of a particular 'focus', but it's not very natural.  I can maybe get a bit more vocal intelligibility out of an array with a PAS shotgun in a swim sounding room, but there's a definite limit of usefulness.  It seems to work better to have an ambisonic array or dual mid side array that can be steered in post to find the best focus. 

The sound of a pump shotgun being armed nearby is probably the most terrifying to an intruder, as you don't need much of a clue in the dark to hit a target.  You will need more drywall work though......

https://www.youtube.com/watch?v=CiHHgjaR0TI

this was eye opening. you better be sure there is NOTHING you love behind or anywhere near someone you are shooting at inside or outside your home. this guy shows regular loads going through 2 internal walls and the external wall.

I always have liked that guy's videos. He actually tests things properly instead of pontificating based on "experience".

Speaking of which - that common trope about racking the slide on the shotgun to scare an intruder could potentially get you in big trouble. It's a sure way to give away your position in the dark.
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Offline Gutbucket

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Re: Musings on shotguns vs rifles
« Reply #22 on: May 26, 2021, 06:59:12 PM »
One of the highlights of my GD taping days was a discussion me and my cohort Chet had with Owsley in the taping section 1st night Boston Garden'93...

Great story, thanks for sharing that.

* I attended (via Zoom) a very interesting historical presentation Saturday night...

And this.  I'd heard the actual recording approaches used at Decca varied significantly.  Any chance that presentation was archived online anywhere?  I'd love to see it.
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Better recording made easy - >>Improved PAS table<< | Made excellent- >>click here to download the Oddball Microphone Technique illustrated PDF booklet<< (note: This is a 1st draft, now several years old and in need of revision!  Stay tuned)

Offline Gutbucket

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Re: Musings on shotguns vs rifles
« Reply #23 on: May 26, 2021, 07:04:24 PM »
On the one microphone > one speaker stereo convention, the wisdom behind it, and carefully breaking it-

I've been out recording smaller outdoor patio gigs a couple times in the past several months before venturing down to Miami to record "for real" at an outdoor garden venue on Monday night.  It was really good to see so many local tapers show up, and hello to anyone reading this who was there. There were folks I've not seen in years, and a couple new folks I met for the first time.  Felt like things getting back to normal.  Anyway, while listening to my recording directly off the recorder over headphones yesterday, I found myself thinking about the whole multi-microphone thing, the two original approaches to stereophonic recording originating in the 1930s, later panophonic-mix based stereo, and my own oddball taper path from stereo to multichannel and back around to stereo.. sort of pulling it all into perspective. 

I realize that:
>Most people listen in 2-channel stereo, over headphones, in cars, maybe to a stereo at home.
>Few will ever experience my recordings played back in the way they were originally intended to be listened, using a 1:1 relationship between the microphones and multiple speakers properly arranged around the listeners.
>I don't even have a playback system setup to do that myself at the present time.
>Simple is often best, not as an end in and of itself, but because of the other things a simple approach makes less-problematic, more straight-forward, clear, or otherwise advantageous.
 
So, given all that, should I go back to recording just 2 to 4 channels all the time, perhaps with upgraded equipment based on a simplification of what I'm doing now?
Not personally, but I now know what microphone channels I'd use in doing that, which I'd eliminate in simplification, how things would differ, and why.  And I feel I can objectively recommend a logical path forward for tapers with similar interests.
Does it make sense and is it worth it to me to continue to record using multichannel arrays that undoubtedly seem ridiculous to most folks? 
Yes, yes, and yes.

Why? At the very least, I very much look forward to getting back to proper multichannel playback again, even if few others ever get to experience that.  It is what really hooked me and I can't let it go. Further, I certainly hope others will eventually get to experience the enveloping, transportive 3-dimensional nature of it, perhaps by way of some sort of head-tracking binaural rendering over headphones.  Yet beyond that, I decided I would still record using these multi-microphone methods even if I were to never have the opportunity to listen that way again, because I find it makes for better, more consistently-good 2-channel stereo output than I am otherwise able to achieve in taper recording scenarios.  The taper recording scenario thing is our biggest constraint and what makes this form of recording different from other forms of recording.  Ironically, it is not recording for surround but the adaptation of that recording method to 2-channel output that represents the point at which I break with the one microphone > one speaker purist stereo rule of thumb.. deliberately and a by lot. "All your base are belong to us."

^
That realization is the primary motivation for this post.  I remember when it came to me, somewhat late and counter to my expectations.  Previously I figured I was following a separate, distinctly alternate recording path, necessarily sacrificing 2-channel reproduction purity for something more correct in a multi-dimensional sense.  Most folks including experts I acknowledge and admire seemed to feel that way (optimize the recording arrangement for either 2-channel stereo or multichannel playback, better not to attempt both simultaneously), the arguments for dong so were sound, the pitfalls clear, and who was I to question 90 years of collective stereo recording history?

Stepping back a bit, I took the multi-channel recording / multi-channel playback path early upon seriously getting into live music performance taping, and did so because I found it especially well suited to conveying unique aspects of the live music experience I was hoping to re-create.  To explore this I was willing to sacrifice 2-channel stereo purity and accepted that as a necessary compromise toward achieving the greater goal.  I was happy enough to find I was able to get my microphone arrangements designed specifically for multichannel playback to work nicely for 2-channel stereo as well, realizing that in doing this I was breaking the traditional one-microphone>one-speaker rule for good of thumb for good stereo purity. Perhaps it worked because I realized early on that achieving optimal channel separation was even more important for really good multichannel playback than stereo, was challenging to achieve across the microphone array, and that the same techniques helped avoid problems when combining multiple channels in a 2-ch stereo mix.  I've posted in many threads here at TS about the complexities of running two microphone pairs with the intention of mixing them and how its not as simple as just putting up your two favorite stereo-pair configurations in the hope that their sum will be better than either alone.  That's where channel interactions between pairs get complicated.  Fortunately I realized that in doing so I gained additional degrees of control quite welcome in situations where tapers otherwise have little control.  I found I gained more than I suffered with the additional channels, as long as their potential interactions were well considered and designed around, and as as long as I was willing to make the commitment to mixing it.

It was at that point I began to make revisions to my microphone arrays which had previously focused on multichannel playback above all else, doing things to optimize them for best 2-channel output in addition to discrete multichannel output.  My hope was to develop a single recording method for myself that I was happy with regardless of playback modality.  The revelation that followed was twin-fold: First that I was able to get it to work better than I'd hoped; secondly and more fundamentally that breaking the underlying one-microphone>one-speaker purity rule was not necessarily a road to perdition as long as it's done carefully with the focus on minimizing its potential problems in light of the potential benefits.

Here's the thing about it- With regards to multichannel playback I had been operating essentially in "purist recording mode" with each microphone feeding an independent speaker for the most part.  That's definitely the case with the three front L/C/R channels, although the surround channels don't always follow a 1:1 microphone > speaker correlation.  But in 2-channel output mode I'm definitely breaking the purity rule by mixing multiple microphone channels together.. not just a couple but five each side.  I actually introduced one additional channel I use solely for the 2-channel stereo mix that does not get used at all for multi-speaker playback: a single figure-8 the addition if which turns the directional Center channel microphone into a Mid/Side pair.  It is one of the channels I would not give up if I were only recording four channels for stereo output alone, and that makes for an ironic situation: My recording arrangement for 2-ch stereo output consists of one more microphone channel than does my recording arrangement for 7-channel discrete output.

Blasphemy I know, but happy to be the weird uncle on this one.

musical volition > vibrations > voltages > numeric values > voltages > vibrations> virtual teleportation time-machine experience
Better recording made easy - >>Improved PAS table<< | Made excellent- >>click here to download the Oddball Microphone Technique illustrated PDF booklet<< (note: This is a 1st draft, now several years old and in need of revision!  Stay tuned)

Offline kuba e

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Re: Musings on shotguns vs rifles
« Reply #24 on: June 02, 2021, 04:13:27 PM »
Thank you for very nice posts about recording for stereo playback. I understand that one pair of microphones for recording is best for professionals. These are pure recordings, but it requires the art of placing the microphones correctly and choosing the right configuration and pattern. Unfortunately, I am not able to do that. And as Gutbucket has already written, tapers have a very limited choice of place to setup and no listening feedback. Gutbucket's multi microphones approach for tapers makes sense to me. I personally like Gutbucket's technique because it helps me with more possibilities and I can learn a lot from it. Recording on multiple microphones and processing it gives me the opportunity to be aware of at least the basic principles of acoustics and to train my hearing a bit. And most importantly, it's more fun for tapers.

 

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