Post by sandyk (RIP Alex, 1939 - 2021) on Sept 10, 2019 10:19:53 GMT 10
In real life you get one set of inter-aural differences for left and right ear for the various cues (in level, time, frequency) per sound source. With stereo sound reproduction there are two sets of inter-aural differences for left and right ear, as created by left and right speaker. So its not the natural way we perceive real sound objects.
There is the experience of some that eliminating this 'cross talk' between stereo channels ie preventing left channel stereo info from reaching the right ear and vice versa will result in better localisation and overall a more natural and life like sound. The reasoning would appear to be that it is closer to simulating how a real sound source is perceived ie returning to one set of inter-aural differences for the various cues.
STC is the expert on such matters. If understanding the effect is like headphones but playing outside, not inside of the head.
Nonetheless, By manipulating the mix of sounds in stereo reproduction (and whatever else sound engineers do like EQ) a very convincing illusion of multiple sound images on a soundstage can be created. Using the stereo phantom central image as example, perception of location relates to amplitude and delay panning (with phase also affected but differently for each frequency). Psychoacoustically the brain perceives that the image is located away from the time delayed speaker and towards the not time delayed speaker and similarly for loudness differential. As I understand it, this is then further influenced by room and speaker interactions. Omnidirectional speakers in rooms with lots of early reflections will produce a larger image that will float between the speakers and tend to stay fixed irrespective of whether you get up and move around the room according to Art Noxon (acoustics engineer and Master Physics).
This is exactly what I heard with mbl radialstrahler speakers in an untreated room (sandyk (RIP Alex, 1939 - 2021) may have heard these at Dennis' place?). In most acoustically treated rooms which dampen first reflections and with more directional speakers (like mine), when you get up and move to the left or right the image and stage shift smoothly to the left or right. In problem rooms, the image collapses to the loudspeaker that is closest to you.
Usually for me the central image is at about the level of the plane of the speakers.The vocal in some recordings push out a bit forward of the speakers. This might be in recordings that have some midrange "presence" boost in the Eq? I think Barry Diament bdiament explained that sometimes due to direct and reflected sound combining in an untreated recording booth, a dip in midrange can occur and the engineer unnecessarily compensates by boosting the mids. When played back it sounds brighter and edgier than it should. He didn't mention pushing the image forwards.
David
-----------------------------------------------------------------------------------------------------------------------------"All music is folk music. I ain't never heard no horse sing a song." -
- Louis Armstrong
Hi David
I remember these problems well , with all the finger clicking by Dave trying to get the best positioning in that room.
I presume that is the occasion you were speaking of ?
Regards
Alex