Surround Sound
On Saturday, November 9, 2013 8:17:38 AM UTC-8, news wrote:
"KH" wrote in message
...
On 11/8/2013 8:07 AM, Gary Eickmeier wrote:
radiation patterns of the speakers
Gee, where did this happen? Did you invent the piano speaker, bass
speaker, and drum kit speaker? This isn't feasible. Nonetheless, let's
assume you have these perfect speakers for discussion purposes.
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what do you know - zing ping pow happening all over again right in your
room! The drum sound will reflect off the front and right side walls, the
bass off the left walls and the piano will remain mainly centered.
Well, let's do a bit of an arrival timeline here. Let's say that in the
new room, the smaller playback room, that new room first arrival and new
in-room zing ping and pow are now only separated by 0.2ms. So what
happens when you play back in the room? Let's see, to be simplistic, you
play one pure tone from each "instrument", in sync.
Sorry, I don't want to trash all of your work on the X, A, B, C diagram, but
I'm getting Deja Vu all over again here.
reality will keep hitting you in the face over and over again every time you make these completely incorrect assertions about stereo.
I said that all of the foregoing just scratches the surface, so permit me to
elaborate just one more level.
There are two stereophonic recordings being made at the live event.
No. There is only one stereophonic recording being made. Even with mulitmiking
One, the
direct sounds and their directions, left to right. Two, the reflected sounds
have been recorded in stereo as well - as you have agreed.
Noooooooo. They are all entwined in the same single stereophonic recording. There is no separate channels for reflected sound. The mics pick up the direct and the reflected sound. You can't separate them. It's all in one recording.
Both the
directions and the timings of those reflections, plus the reverberant tail
as the sound dies out during the reverb time of the hall.
No, the "directions" do not die out. that doesn't even make sense.
No, we cannot find enough channels to do each reflection with a direct
loudspeaker, nor could we do a new setup for every recording.
Again this doesn't even make sense. You can't mimic the reflections of the original venue without recreating that venue. That is never going to happen.. That is the primary reason the inventors of stereo recording and playback never went that route. It would be futile.
What is
important to audibility is that these reflected sounds NOT come from the
same directions (sources) as the direct sounds that were recorded.
Actually that is not important. If it were, all we would ever hear with playback is the directional sound coming from the speakers. Funny thing how we hear directionally. It has to do with phase, amplitude and spectral content. Stereo recording and playback utilizes this to create an aural illusion. If it didn't work then stereo would sound like two point sources. But it does work. And it does so without bouncing the sound off the walls. That is not a part of how stereo works.
This is
why you cannot just wipe out the room and listen to the speakers only, in
near field or any other manner.
Actually you can. And it works well.
Nor is it necessary to have precisely the same radiation pattern as each
musical instrument - just a general pattern will suffice, one that is
oriented toward the model, not the live sound itself, in a general way, not
for each instrument and each recording.
How on earth can you possibly make such a claim? Have you made comparisons between speakers and live instruments in concert halls? Not that it matters..
The main requirement is to get the spatial patterns more correct and
separate the later arriving reflected sounds from the first arriving direct
sounds.
That is just going to be a sonic mess. as has already been pointed out to you all you are doing is taking the original two or multi channel recording with all the reflected sounds of the hall that are on the recording and then making them echo off the walls of the playback room. Sonic smearsville USA.
This will be done simply by time delay. In the model, a matrix of
real and virtual speakers
real and "virtual" speakers? What is a "virtual speaker?" I probably shouldn't have asked.
is set up equidistant from each other such that
the loudnesses of all 8 of these sources is about equal and there will be a
summing localization among them all, in depth as well as width, so that the
recorded sounds come from a region within this structure somewhere behind
the plane of the real speakers and from wall to wall in width. This
structure, a spatially arrayed, temporally delayed, spectrally shaped sound
field simulator then becomes the "canvas" on which the recorded sounds can
array themselves.
And this is supposed to work with what recordings? What you are proposing is just a seemingly random made up new flavor of multichannel and then mixing room echo into it.
The main point is that the reflections from the recording come from correct
spatial angles on playback,
That would not happen with what you are proposing. Wouldn't even be close.
which MUST be different from the direct sounds.
Your whole timing discussion is mostly irrelevant to this spatial
requirement.
No it was not irrelevant. the timing of reflected sounds gives us our aural cues to recognize the illusion of original sound space.
The fact that the timings of the reflections in your room are
shorter than those in the recording matters not. Those timings remain as
recorded, but now come from spatially similar angles during playback if
properly recorded.
It matters hugely. This is really old news. Take a recording with substantial real recording venue reverb on it and play it back into a reverberant playback room and you get all kinds of confusing spacial cues that pretty much destroy each other. You end up with poor imaging and a lot of smeared sound. IOW a complete sonic mess.
At this point you declare that Eickmeier is full of it once again, because
there is no way to separate out the reflections from the direct sound in the
recording in order to make this fantastical model work. You would be wrong.
No we would all be right. It's not like this is anything new.
It is all done with time delay.
Nope, no such thing as time delay that seperates the reverb and direct reflections from the direct radiation of the instruments. Once it hits the mics it all becomes one signal. Taking that signal and adding time delayed playback over the regular playback just smears the sound.
Much like a Hafler or Dolby Stereo playback
system can extract the ambience from a recording and wrap it around to the
sides and rear, the time delay of the reflected sound in your room can
decode the reflected in the recording for the frontal soundstage.
Those systems can't actually extract the ambiance from a recording.
How? There
can be only one first arrival, and that HAS to be from the actual speakers
in the model. Later arriving, longer duration sounds will come from the
virtual sources or reflections in your listening room if the balances are
all about right.
The audible result is that for tight dry recordings with none or little
reverberance contained in them, the direct sounds just take on a harmless
image shift toward the reflecting surfaces and form themselves as an aerial
image slightly behind the plane of the speakers.
And what recordings that actually exist in this world would you be refering to here? And let's not forget that this is a huge issue for any attempt to reinvent stereo/multi chanel recording and playback. Just ask JJ Johnston. He helped develop such a system that by all reports was a substantial step up when it comes to realism. But the problem is we have over half a century of recorded musical heritage and any new system has to be retro compatible for that vast array of existing recordings. If not then what is the point? Ditch our music collections and wait and hope for the new recordings made with the new system? Not going to happen.
More reverberant recordings
take on the spaciousness and depth similar to the live situation and for
similar reasons. As long as zing ping pow happen within the fusion time, we
perceive them as part of the direct sound but with the spatial signature of
the model, which has been designed to be similar to the live model.
Except it doesn't work. It doesn't work because that is not how those recordings were designed to work. what you get is the good old Bose 901 sound. No thanks.
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