Yes, two SASS units back-to-back will work, as long as you put a pretty big
barrier between them to reduce phase cancellation and summation effects at
higher frequencies. An expert has suggested that I use a 4' X 4' (or larger)
sound absorbent panel for this, cutting a rectangular hole in the middle to
allow for two SASS's to be inserted and held firmly in the center of the
barrier. This would involve making a special frame to hold the two SASS
units together, placing one on top the other and pointing them in opposite
directions with the mikes of the two units more-or-less aligned vertically
to reduce phase problems).
Four speakers would then be used for playback. The front channels would go
to two front speakers placed out to each side and a little in front of the
listening position. The two rear channel speakers would then be placed out
to the sides but a little behind the listening position. I think this would
produce a very nice 360 degree soundstage.
Bernie's tetrahedral approach can also yield good results in this respect.
Lang
> Lang Elliott wrote:
>>
>> When I do such a test with my SASS, using headphones, I get a really nice
>> 180 degree depiction, the only weakness being that front and center sounds
>> like it's coming from above.
>>
>> As I go around behind the mike, mostly it sounds as if I've turned around
>> and proceeded back in front of the mike. This is typical of all binaural
>> setups, unless they're tweaked for individuals. Even then, rear sounds often
>> are projected toward the front.
>>
>> This is one reason that I've decided to use my SASS recordings primarily for
>> 180 degree frontal playback (with some convincing 3D or height effect). This
>> can be simply accomplished using two conventional full-range speakers, each
>> placed out to the side (as I've described previously). One clear advantage
>> of using speakers is that sound sources originating front and center come
>> through sounding like they're front and center, as opposed to headphones
>> which often render them overhead center.
>
> I'd think to get a 360 from the SASS setup you would really need to use
> two SASS mics back to back recording to 4 channels.
>
> For me, most stereo in headphones sets up behind me, or so it sounds. I
> can get it more likely to sound out in front by reversing the
> headphones. And I have no idea why.
>
>> While a lot of research is being done that could eventually extract a full
>> 360 degree arc from two tracks (possibly including lots of 3D or height
>> effects), it is much more reasonable at this time to investigate ways to use
>> 4-track recording to produce an encompassing playback soundstage.
>
> The one I can think of that should be able to do 360 from two tracks is
> a pair of figure 8's, like the MKH 30's. Or if you want to match the
> noise specs of your MKH 20's and also have something that provides
> actual sound signals over the full range of the higher sampling rates
> you like, you would use two MKH 800's in figure 8 settings. Those are as
> quiet as the 20's, maybe quieter, and go to 50khz. One place where the
> increased frequency range might mean something is in surround sound.
> I've not seen any matrix software for crossed figure 8's to 360
> surround, though there probably is some.
>
> It might be interesting to try two figure 8's with a foam barrier system.
>
> I'd think that you could do it with three channels using one figure 8
> paired with two matched mics pointing front and back. I understand that
> it's usually done with two figure 8's making it two MS setups back to
> back. Which would be 4 channels.
>
> Walt
>
>
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>From Tue Mar 8 18:22:21 2005
Message: 2
Date: Sun, 17 Feb 2002 19:03:21 -0500
From: Walter Knapp <>
Subject: Re: Re: stereo recordings
richpeet wrote:
>
> In case anyone noticed that I didn't post the results of the foam
> block head stereo baseball field baserun test. The mic failed the
> test so I didn't. I am back to the bench. It didn't fail serious
> but needs work before use. I will post proto 2 if it works better.
You may find that test is very hard on stereo mic setups.
Be interesting to see what proto 2 is like.
Walt
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>From Tue Mar 8 18:22:21 2005
Message: 3
Date: Mon, 18 Feb 2002 03:14:20 -0000
From: "richpeet" <>
Subject: Re: stereo recordings
I found on my first attempt that standard 1.5 lb foam rubber was
letting too much sound through. I have switched to 1' X 1', 3.0 lb
foam and placed a 1/2" wood barrier in the center. I have holes for
hanging from trees, it sits well on the ground and picnic tables, and
I will mount a angle iron shortly for a tripod mount. The mics that
are not visible are 2 Sennheiser ME 62's.
I first recorded with it today and found it to be much better. I
have not done the base run test yet but here is some fun sounds with
some lost in the mp3 translation.
photo is about a 200 kb download at:
http://home.attbi.com/~richpeet/proto2.JPG
stereo sound is a 1.7 meg download at:
http://home.attbi.com/~richpeet/proto2.mp3
PS If you are guessing what the sounds are of I will be glad to e-
mail you if you are unsure and want to know.
--- In Walter Knapp <> wrote:
> richpeet wrote:
> >
> > In case anyone noticed that I didn't post the results of the foam
> > block head stereo baseball field baserun test. The mic failed the
> > test so I didn't. I am back to the bench. It didn't fail serious
> > but needs work before use. I will post proto 2 if it works
better.
>
> You may find that test is very hard on stereo mic setups.
>
> Be interesting to see what proto 2 is like.
>
> Walt
>
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