David, Simon. It's been a few years since read the Prologic papers, but IIRC the active steering was to make up for the small amount of physical separation between typical home speakers. Not needed in the cinema, but needed at home to more closely approach what is heard at the cinema.
With all the new formats, discreet channels and remixes for video, I doubt it's of much use these days.
With all the new formats, discreet channels and remixes for video, I doubt it's of much use these days.
Member
Joined 2003
Weather has been beautiful here, so a little late to the in/out of phase tests.
These shots were taken from the LP in a fairly symmetrical room with fairly directional speakers (subs off). 1000ms, 1/3 octave with identical impulse start for both channels.
First, right channel blue, left black:
In and out of phase:
These shots were taken from the LP in a fairly symmetrical room with fairly directional speakers (subs off). 1000ms, 1/3 octave with identical impulse start for both channels.
First, right channel blue, left black:
In and out of phase:
Here could be interesting paper for individual perception of phantom sources:
AES E-Library Individual Localisation Behaviour for Perception of Virtual Sound Sources
"Test results normally indicate very large variability in perception of lateral virtual sound sources"
- Elias
AES E-Library Individual Localisation Behaviour for Perception of Virtual Sound Sources
"Test results normally indicate very large variability in perception of lateral virtual sound sources"
- Elias
Lateral, i.e. a side speaker pair (@60° and 90-110°)? That's very old news - from Blauert, "Spatial Hearing":
An externally hosted image should be here but it was not working when we last tested it.
Elias, are you seriously still trying to find proof 60° stereo wouldn't work?
Tony, I wouldn't worry too much about phase at such low frequencies as long as the FR is good.
Elias, I haven't read the paper, but from the abstract you quoted it seems the authors suspect *other factors* were causing the erratic localisation results in some recent experiments conducted by third parties. So they investigate it in this paper. I don't think, from the abstract, they are arguing that phantom images are not possible.
Are you still trying to back-rationalise your personal localisation experiences by searching out science that supports it, rather than accept the mainstream consensus? Take care, or you might become the audio equivalent of the creationists who cherry pick little pieces of science and proceed to argue it proves their beliefs true.
One way to look at it is to consider the unit and its reflection. If the unit is 1/4 wavelength off the surface the 2 units are 1/2 wave apart and a null would happen in the upwards direction. For wavelengths longer than that the unit and its reflection would be in phase in all directions. At that point (and for frequencies lower) the units are essentially joined and the unit must be in half space.
4 ft would give a 1/2 wave separation at 69 Hz. For frequencies below that the unit is essentially in half space. Of course the room's standing wave pattern will always apply and may overide the simple boundary effect.
Why are you asking?
David S.
This was the point that I was going to make. In a real room the modal effects overide any measurement except one that is in-situ. The room dominates everything in the low modal density region making free-field or infinite baffle data equally unrealistic.
Probably the tenth time I read the Allison paper it dawned on me that he had averaged curves from houses all over Boston. The boundary effects would be constant for a given distance to the boundary, but the particular standing wave effects of every room would be different and would average out in the mix.
David S.
David
Quite true. Using an average like that may make sense in some sense, but its just going to "average out" exactly those things that you need to know, leaving behind something that has lost its meaning. The room dominates the situation, every room is different (and not just a little, a lot) so each room is its own study and generalizations are more misleading than helpful.
Quite true. Using an average like that may make sense in some sense, but its just going to "average out" exactly those things that you need to know, leaving behind something that has lost its meaning. The room dominates the situation, every room is different (and not just a little, a lot) so each room is its own study and generalizations are more misleading than helpful.
With two horns covering your entire front wall? Or maybe a large driver matrix for beam forming? WFS?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.