Peter Oxford wrote on Sun, 29 August 2004 05:49 |
Dear Bob,
How are you all at home now? Has everything settled back to normal yet? I expect within the community there are plenty of problems that need to be dealt with. I just couldn?t begin to imagine.
|
We're doing fine, thanks!
You're arguing a fine point. I concede that you have found that Thomas Lund notes that 5.1's sweet spot can be even worse than stereo's if one resorts to power panning. Well, that's because now we're panning on more than one axis!
I think yours is an academic argument that can be answered with "avoid power panning". Furthermore, let's take a front pair mix which is "totally power panned". This stereo mix has a terribly small sweet spot. Move off center and everything seems to move to that side. This can be alleviated somewhat by speaker toe-in, etc. But the laws of psychoacoustics prevent too much improvement in this way.
Now, if you convert the 2 channel "terrible power panned" mix to trifield, the sweet spot opens up! The point being that surround, even 3 channel reproduction, is better than 2 channel and does have the effect of a wider sweet spot.
Thomas Lund's point ONLY NARROWLY APPLIES to if you dare to power pan material between front and surrounds. This should be avoided at all costs. You're arguing a small point here. Thomas and my point still prevails, that "well-mixed" 5.1 has a far bigger sweet spot than any 2 channel recording.
Consider this: Start with a stupidly power-panned multi-mono stereo mix that has a terribly-small sweet spot.
Add some decently natural surround to your simple power-panned stereo mix. Use proper delays, early reflections, natural reverberation, etc. as Thomas Lund suggests. PRESTO! As I said---the result is a wider sweet spot. Wider sweet spot in surround than ever in stereo. You can stand somewhat further from the front speakers but due to Hass, your ears will locate the source as coming from the front.
By means of the Hass effect, and because you have NOT power panned from front to surround, the listener will find the localization of the source improved. The source is ANCHORED better in the front. The ambiguity of the original front power-panned stereo mix is still there, though it can be greatly improved through Trifield conversion to 3 channel, even if the source was still purely power panned, the left-to-right (horizontal) sweet spot and the ear's localization ability of center-located material will instantly widen when using the 3 speakers.
Quote: |
And a Baritone (one of the world?s best) sang out a note from the stage ?throwing his voice? which caused me to spin round completely, as it sounded to me as if the singing was coming from behind me and to the right. I looked back at the singer. He looked directly at me and gave me a warm smile, we smiled at each other. He had played a trick on me with the acoustics of the Hall, quite deliberately.
|
Yeah, been there, done that! Bad acoustics, buildup of inphase material in the back of a bad hall. A bit of gazebo effect and you're in trouble. I once had to record in a hall in New York City that has curved back wall/corners. Sound in the front left is "amplified" in the rear right. I put a pair of spaced omni ambience mikes in the back and found that by reversing them left versus right I got a much better recording.
Quote: |
I would make one further point. Just as in a real concert hall I would expect to be able to sit in any, of quite a number of seats, and still hear an excellent balance of sound wherever I was. Whether I am listening in stereo, surround sound, or whatever format was used to present material. I would expect to be able to sit in a completely un-optimal position, and still hear a fairly good balance of sound. This is what real life experience in concert halls is like.
|
And this is EXACTLY the intention of 5.1 and the intent of Thomas Lund's article and my point about the sweet spot being larger in 5.1 than in stereo... only by twisting or narrowly interpreting Thomas' words can you make a counter argument.