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Re: Soundscape Recordings

Subject: Re: Soundscape Recordings
From: Lang Elliott <>
Date: Thu, 07 Feb 2002 08:34:55 -0500
Yes, Rich is right. Compare the freq response specs (in the pdf files you
can download from Sennheiser's website www.sennheiserusa.com). There's not a
huge difference between the two.

Lang

>> From the low-end guy on the street that still cares about quality.
> 
> Do not dismiss using your me 64 as an omni so fast. It may be that a
> piece of tape over a couple top side vents will come close, or be the
> same as a me 62. There just is not that much difference in the two of
> them.
> 
> If it tests out ok than you may have bought both.  Tech support can
> give you some info and I can give you a test of pink noise recorded
> direct and at 90 degrees on a me 62 that you could compare to your me
> 64 with tape.
> 
> 
> --- In  Vicki Powys <> wrote:
>> All,
>> 
>> I have learned a great deal this week about stereo recording,
> thanks to all
>> your postings on this topic.  Your generosity in sharing such
> information is
>> very much appreciated.  I now understand for the first time how my
>> coincident pair of cardoids will have an uneven frequency response
> to the
>> sides.  And that a SASS set up would not.  I do love the effect of
> binaural
>> and as all my listening is through headphones I will certainly
> experiment
>> with binaural, eventually.
>> 
>> I realize now I must have omni-directional mics for binaural to
> work.  So
>> I'll start saving up for two Sennheiser ME62 mic capsules which in
> Australia
>> are currently $ Aust 320 each (I already have the power modules).
> Lang's
>> favourite Sennheiser MKH 20 omni mics would cost me $ Aust 2,540
> each, (plus
>> power unit) so they are totally out of the question!  Meanwhile my
> cardiod
>> pair of ME64s, home-mounted on a monopod as a coincident pair with
>> adjustable angle, are easily carried and quick to set up in the
> field.
>> Knowing of that dip in various frequencies to the side will help me
> to
>> better consider the angle I set them at, in any given environment.
>> 
>> Thanks again,
>> 
>> Vicki Powys
>> Australia
>> 
>> 
>>> on 7/2/02 1:39 AM, Lang Elliott at  wrote:
>> 
>>> Walt:
>>> 
>>> "Uncolored" simply means that the mike itself is not coloring the
> sound and
>>> that it's frequency response to sounds within a particular spread
> is pretty
>>> flat. In other words, it faithfully renders the sound that
> arrives at the
>>> mike. The SASS omni-mike setup does very well all the way out to
> 180
>>> degrees. Beyond that sounds become muffled because of frequency
> variable
>>> attenuation toward the rear. But at least it provides rather
> uncolored
>>> response to signals originating out to the sides.
>>> 
>>> Compare this to a coincident or near-coincident stereo setup
> using cardioid
>>> mikes, where attenuation varies considerably with frequency as
> sounds move
>>> more and more off-axis. This is due to the uneven falloff of
> different
>>> frequency bands typical of directional mikes. As a result, a high
> pitched
>>> sound off to the side will be considerably attenuated, while a
> low pitched
>>> sound from exactly the same location will have little
> attenuation. Thus, a
>>> broadband sound coming from the side will be extremely "colored"
> by the
>>> microphone setup itself, due to drastic attenuation of the highs.
>>> 
>>> Lang
>> 
>> 
>> 
>>> Re: Recording Natural Soundscapes and the 360-degree issue
>>> 
>>> Good comments Bernie and you're absolutely right about "360". And
> Walt is
>>> correct in saying that the ultimate 360 is actually 3D, with
> sounds coming
>>> from all directions, including overhead.
>>> 
>>> That said, it is good to keep the following in mind:
>>> 
>>> 1. If, as a listener, you desire more than the 60 degree spread of
>>> conventional stereo sound, then you'll have to adopt some other
> playback
>>> techique, be it headphones or multiple speakers, or other
> positions for your
>>> two main speakers.
>>> 
>>> 2. All stereo microphone setups hear in a full 360 degrees, it's
> just that
>>> highly directional setups greatly attenuate sounds to the rear.
> But even
>>> with very directional setups, loud sounds from behind are
> recorded and will
>>> be heard upon playback.
>>> 
>>> 3. Whatever soundstage the microphone setup records will be
> collapsed into
>>> the playback soundstage. THIS IS A VERY IMPORTANT POINT, and
> here's a
>>> example of what I'm talking about:
>>> 
>>> Let's say you record a soundscape using a mike setup such as the
> Schoeps
>>> KFM6 Sphere, which is 2-channel binaural and which records a full
> 360
>>> degrees, without any attenuation of the rear. Now, let's say that
> you play
>>> such a recording back using a conventional 60-degree arc stereo
> speaker
>>> setup. This results in the 360 degree recording being "scrunched"
> into a 60
>>> degree frontal soundscape. Another way of saying this is that the
> 360 degree
>>> natural soundstage is "compressed 6:1" into the smaller
> soundfield. You
>>> should also realize that all the signals coming from the rear of
> the Schoeps
>>> Sphere are simply being "superimposed" on the frontal signals. In
> other
>>> words, sounds that happened to the rear will sound as if they're
> coming from
>>> the front when played back using the conventional speaker setup.
>>> 
>>> For instance, when you're recording in the field you might notice
> that a
>>> bird is singing loudly from behind you and to the left. Using
> almost any
>>> stereo mike faced forward and then playing your recording back
> over a
>>> conventional 60-degree speaker setup, the bird will sound as if
> it's coming
>>> from just inside the left speaker, which would be perhaps 25
> degrees left of
>>> center, not at all cloe to where the bird was located in the
> wild!!
>>> 
>>> It is always good to think this way, even when using a stereo
> setup that is
>>> directional. In such cases, loud muffled sounds from the rear are
> recorded
>>> and they will appear in the frontal soundstage upon playback.
> Furthermore,
>>> they may sound "weird" because of their muffled quality.
>>> 
>>> 4. When listening to true binaural recordings over headphones,
> one can
>>> sometimes get fair imaging of sounds to the rear, but more often
> than not
>>> the rear sounds appear to come from the front, similar to what
> happens with
>>> speakers but within a broad 180 degree soundstage.
>>> 
>>> 5. Currently, it is not feasible to get true 360 degree 3D sound
> using only
>>> two speakers. There are some very advanced recording and playback
> systems
>>> that approach this, even using two channels, but most require
> multichannel
>>> recorders and multi-speaker playback systems (eg. the Soundfield
> mike and
>>> Ambisonics playback system). Conventional 5.1 Surround Sound DOES
> NOT
>>> produce 360 degree 3D sound and it is not a good choice for nature
>>> recordists for the reasons mentioned in other e-mails.
>>> 
>>> 6. Lang's current microphone choice for soundscape recording is
> his modified
>>> SASS, which receives an "uncolored" 180+ degree frontal
> soundstage, with
>>> moderate rejection of sounds to the rear.
>>> 
>>> 7. Lang's current speaker playback system of choice (for his SASS
>>> recordings) is to place two speakers almost straight out to the
> sides to
>>> produce a 180+ degree playback soundstage. Remember that the SASS
> also
>>> records sounds coming from the rear, even though they are
> attenuated. When
>>> using the 180 degree speaker setup just described, the rear
> sounds are
>>> projected or superimposed upon the frontal sounds, creating a 2:1
>>> compression, which is much less compression than the 6:1 produced
> using a
>>> conventional stereo speaker playback setup.
>>> 
>>> Does all this make sense? Really, it's an attempt to clarify how
> one's
>>> microphone hears the complete 360 degree natural soundscape
> (including what
>>> is being emphasized and what is being attenuated), and then how
> one's chosen
>>> playback system renders what the mike hears into an indoor virtual
>>> soundstage. 
>>> 
>>> As nature soundscape recordists, it seems that we should
> gravitate toward
>>> recording and playback techniques that give us the most natural
> and
>>> realistic illusion when we listen to our recordings indoors, with
> a full 360
>>> degree 3D effect being our ultimate goal.
>>> 
>>> 
>>> 
>>> lng
>>> 
>>> 
>>>> Wild Sanctuary wrote:
>>>> 
>>>>> It should be pointed out that none of the stereo systems offers
> a true 360
>>>>> degree listening experience by itself. To me, a realistic 360
> degree
>>>>> experience means that you can place the listener within a non-
> headphone
>>>>> tethered sound field and anywhere he/she turns his/her head,
> they will hear
>>>>> the sound accurately portrayed from that perspective. 360
> degree sound is
>>>>> listener-oriented and determined just as sound arrives at our
> ears in the
>>>>> real world.  That can be currently accomplished by discrete 4-
> channel
>>>>> recordings or (as we have recently tested) two M-S systems
> placed
>>>>> butt-to-butt, and perhaps some other method(s) not yet well-
> known or
>>>>> explored like, perhaps, a tetrahedral array (giving the added
> advantage of
>>>>> height as well as depth of field on the horizontal plane).
>>>> 
>>>> I'm even more picky as I visualize a 360 setup as being actually
> a 3d
>>>> volume. And I'd also prefer that more than one can enjoy it at
> the same
>>>> time. That's going to be harder to do. For now I'm keeping my
> goals much
>>>> simpler, good stereo. That may wander into binaural setups or M-
> S, but I
>>>> am working on the stereo field, not surround.
>>>> 
>>>>> It's all a matter of taste. Test a whole bunch out and go with
> what pleases
>>>>> YOUR ear. I recommend using systems that are durable, easy-to-
> use, provide
>>>>> a good to excellent signal-to-noise ratio, and a reasonable to
> great
>>>>> illusion of space. Except for the specially configured SASS
> system
>>>>> described by Lang (and which we WILL explore when we get the
> bucks to do
>>>>> it)
>>>> 
>>>> That's the big problem with Lang's system. I figure I'm going to
> go two
>>>> steps on it, start with cheaper capsules to see if I like it at
> all,
>>>> then try for the expensive stuff. That way I can also explore
> some
>>>> technical issues that I'd not try using MKH20's. Or for which the
>>>> MKH20's are unsuited. Working with a built up mic is a
> disadvantage in
>>>> some ways.
>>>> 
>>>> The issue of practical to use is a important one for me. Does
> not matter
>>>> how wonderful the mic, if it's hard to transport or use, or
> can't stand
>>>> the outdoor environment, it simply won't be used. Whatever I
> have must
>>>> fit easily in a car with lots of other stuff, preferably in a
> ready to
>>>> go state. Due to the sort of locations I often have it must also
> be
>>>> something that can be hand held. Those criteria weed out some
> types.
>>>> 
>>>> , we use all types and all configurations depending on the
> application
>>>>> and what we wish the end result to be. Call me an end-resulter,
> if you
>>>>> wish. (I won't be insulted 'cause I'm just wired that way.) I
> go for what
>>>>> the illusion will sound like on a CD or in a public space
> installation so I
>>>>> don't necessarily monitor for the pleasure of the moment in the
> field. I'm
>>>>> happy enough to be there in the first place. Rather I monitor
> just to be
>>>>> sure that the M-S recording on tape or disc is as fine as it
> can be knowing
>>>>> that in the studio it will be close to what I imagined it
> should be, then
>>>>> detach the headphones. The M-S system we use is more difficult
> than other
>>>>> systems because it is not intuitive. What you hear using a
> simple pre-amp
>>>>> in the loop is clearly not a representation of what can be got
> in the
>>>>> studio or lab when doing the final mix. So I usually recommend
> simpler
>>>>> stereo systems to begin with.
>>>> 
>>>> As I often use the stereo field in the headphones to align the
> mics,
>>>> especially when hand holding, I've been looking at the business
> of how
>>>> to handle the M-S system for that. Aiming by sight in the dark
> is not
>>>> that precise. So, I'm wondering about a split system that feeds
> stereo
>>>> to the headphones, and the regular signals to the recorder for
> later
>>>> processing. I don't care if the stereo field I get is the best
> listening
>>>> one, just want to aim with it. Do you have any suggestions in
> this
>>>> regard? Hopefully something reasonably priced.
>>>> 
>>>> 
>>>>> Lesson the long way 'round: use different mics and find one or
> several you
>>>>> like.
>>>> 
>>>> I get the feeling I'm going to find I like several. But that
> each one
>>>> will do best at different things.  So, just like I have a camera
> with
>>>> several choices as to lenses, I am working in the direction of a
>>>> recorder with several choices of microphones. And knowing those
> mics as
>>>> well as I know camera lenses.
>>>> 
>>>> Each microphone (or microphone combination) is going to take
> some time
>>>> to really get used to what it does. So, while I have initial
>>>> impressions, those are subject to change.
>>>> 
>>>> Worst part about experimenting is how much the mics cost. I just
> don't
>>>> think it would be effective to rent them for a short period to
> evaluate
>>>> them. Hopefully, by using things like Ebay to keep the costs
> down I
>>>> won't go broke doing it.
>>>> 
>>>> Walt
>>>> 
>>>> 
> 
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