Nothing. As far as I'm concerned that reference is talking a load of twaddle in this particular quote
I'm entirely with you on that one. The quote is completely wrong. The reasoin that our hearing has not developed very well above say 8 kHz is because of the extreme amount of HF absortion in the air at these frequencies. Hence, with distance, the HF response tends to fall, not increase. In a large auditorium, air absorption at 10 KHz is greater than the absorption at the walls and almost nothing above 8-10 KHz exists in the reverb field. At some distances even the direct field is strongly affected.
Of course this is true, an omni in a reverb chamber would have a seet spot everywhere. It would also have no imaging capability at all. To me thats a non-starter. Imaging is critical and spaciousness is desirable, but not the other way arround.
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Ah, oui, bien sur. Not to worry, I took French lessons from that famous Spanish cow.
I think this is one of those issues where people have different tastes and priorities. I clearly remember the spatial impression I heard when I went to a performance of an orchestra in a large auditorium for the first time, a few months ago. The "image" you hear isn't sharp at all, but you can clearly hear the effects of the hall. Sharpness of imaging then, is not very important for realistic reproduction at home; spaciousness, on the other hand, is important for reproduction in this case.
Last week on Monday I listened to keyser's highly directional speakers. When I heard a band playing outdoors the next day, I concluded that the sharp imaging I heard on the speakers can be considered desirable for faithful reproduction (although I do miss a little spaciousness and "fullness" of timbre with his design).
In a nutshell, I think the order of these priorities may well depend on musical tastes and your live references. I do, however, believe that any polar pattern should approach Constant Directivity. In my experience, speakers with fairly increasing directivity didn't do the trick (as far as correct timbre is concerned).
Nothing. As far as I'm concerned that reference is talking a load of twaddle in this particular quote
Yes, the first quote has me scratching my head. Unless the source is large relative to the observation distance (i.e. you are in the near field) than it should fall off 6dB per...
The rest of the paper is a nice readable summary of the topic.
David S.
and here is how it actually sounds as reported by a Grammy winning, legendary producer (Bob Olhsson, posted by Him at gearslutz forum):
underlines mine
Graaf, you already quoted that part in post #509. Have you ever heard a speaker that has high directivity? I suppose not, because otherwise you would not keep repeating yourself over and over. There are many things we can disagree about, but anyone who has heard high directivity speakers would tell you they image more precisely than omni's.
Well not anyone. See my post just above yours and also my post here:
http://www.diyaudio.com/forums/mult...-pattern-stereo-speakers-113.html#post2712366
See my post just above yours and also my post here:http://www.diyaudio.com/forums/mult...-pattern-stereo-speakers-113.html#post2712366
In my experience, in a 'normal' room, nothing images as sharply as high directivity speakers. Mind you, I'm not saying I don't enjoy listening to anything but high directivity speakers, I'm only saying they have the sharpest imaging. I'm also not saying wider dispersion speaker can't have good imaging. I've listened to the Linkwitz Pluto's a couple times and they had pretty good imaging too. But they were always far from the walls and I was sitting relatively close to the speakers. I'm quite convinced though, that strong direct sound and a sufficient Initial Time Delay Gap (ITDG) help to make imaging more precise/sharp.
In my experience wider dispersion speakers setup in a conventional way (i.e. maybe about 1 meter from the sidewalls) can have nice and broad imaging, with a lush sound. They can't have very sharp imaging.
Medium size hotel ballroom. See here: http://www.diyaudio.com/forums/diyaudio-com-articles/170305-midwest-audio-fest.html
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Joined 2009
keyser,
I'm a bit surprised at how similar my experience (#949) was to your description. My speakers are wider dispersion than yours but our rooms are almost identical.
I found that slight toe out works best for my setup. Have you tried it? What about minimizing contralateral reflections by pointing the speakers to cross behind the sweet spot?
I speculate that strong contralateral reflections although beneficial for enforcing the center phantom image have detrimental effect on the edges of the image. With contralateral reflections, when material is panned to the side the listener would get cues of similar intensity from conflicting directions. It was mentioned in an earlier post that the brain tends to ignore conflicting cues and to enforce compounding ones. That seems to explain the effect that markus and I observed of narrow image with speakers toed in and wider image when they are toed out.
I am afraid that is true. For a performance of an orchestra you would like to have the 'you are there' experience. Maybe some interaural crosstalk cancellation does the trick for stereo, I would be interested to hear such a recording. But multichannel audio should be much more suitable to provide that experience.
I think the most believable normal stereo recordings are the ones that provide you with a 'view through a large window to the acoustic space of the recording'. There recordings contain sufficient cues to give an impression of the acoustic space. They also place the orchestra, trio or band at a larger distance than the usual 3 meters.
I think different authors come up with different numbers because they may use different test signals.
I strongly believe this is also frequency dependent, and not constant ! Then to optimise a toe-in system, the directivity should be frequency dependent to follow the optimum. It would mean constant directivity is not optimum directivity pattern for stereo speakers.
- Elias
I thought it goes without saying that "You are there" and "They are here" requires a different recording technique ? Obviously the same recording is not optimal for both. I'm not sure why you're even labouring this very obvious point.
Just a philosophy: How to record a singer in an anechoic chamber to achieve "you are there" ??
It must be possible, since by now we know that stereo is capable of anything
- Elias
thank You
but were they far enough from the walls to secure the allegedly necessary 10 ms of delay for ipsilateral reflections? 10 ms is over 3 metres of sound path difference
for example - was this requirement met at at the Dayton speaker contest with those Walsh/Ohm modified speakers?
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