AQ"s DBS A reality?

[jneutron]

GREAT stuff. I'll look up what I don't understand of the specifics but I think generally - even for those of us that are scientifcally challenged - you've given us another example of what happens when opinions are taken as facts. But could you clarify what you mean in item #6? What cues are changed and how? Thanks.

Oh, sorry for the question mark in the title - tried to edit it out but it'll only let me edit text.

When we hear a sound, our ears give us information that the brain uses to interpret where it is coming from. Our ears give the brain two essential things..the ear to ear time delay, and an ear to ear level difference. With both of these, the brain has enough to go by to localize a source.

If a source is directly in front, there is no arrival difference and no intensity difference.

If a source is on our right, the right ear gets it first, and gets it loudest.

The music recorded in a studio is put onto the final two channel recording by using a pan pot, which uses only intensity as a side cue. Unfortunately, humans are not hardwired to interpret only the intensity difference to locate a sound, we are wired to also use the delay from ear to ear.

We have to learn, or acclimate, to this different style of sound locating. It is unnatural. With headphones, the brain interprets the information as being within the head (unnatural for most, I think). With speakers, the added ear to ear stuff helps confuse the brain into thinking the source is in front of us. But still, in a very un-natural way...speakers produce 4 images for one intended image source. 1, the desired image cause by the right ear getting the right signal, the left the left signal. 2, the image that happens when the right speaker gets to the left ear, and the left to the right ear. 3, the left speaker by itself, and 4, the right.. temporally and amplitude wise, we tend to interpret #1 as the primary image, but that requires the brain reject the other three. A learned response..

Any part of the reproduction chain that can change either the intensity difference or timing difference between channels, will alter the cues the brain needs to localize. Once a change is made, it takes a while to adjust...remember, the brain has to learn how to reject the spurius images.

Our sensitivity to these ear to ear differences extends down to the 1.5 to 5 uSec range for time delay, and strange as it seems, less than .1 dB..

I know of nobody in the audio world who has demonstrated the ability to measure those type of differences accurately at the low impedances of a speaker, even for simple two tone sines, nevermind a complex signal.

The researchers I speak to do not even understand the basic concepts of 2-D localization, nevermind the more complex angular and spacial first and second order derivatives necessary for differential localization and image stability.

It's not rocket science, for goodness sake...sheesh..

Cheers, John

PS...differential localization is our ability to determine the difference in spacial location of two sources, like two people ten feet away side by side talking to us. We are far more able to discern the relative positions of two people in space than we are to discern one person's absolute location. We key on one source as a reference point.



Image stability is how solid the virtual image is in space, even though the signal is being massaged either by the electronics, or by the position of our head. As an example of this, consider the toe in of a speaker that beams it's highs..if the beams intersect in front of you, when you move to the right, the left signal becomes louder while the right becomes weaker, shifting the image to the left. That is not what happens with a real source..and if the mids do not beam, the mid image will act more naturally. The effect will be to seperate the frequencies of the image spacially..Disembodiment.