You want to find out what differences people hear between live and recorded sound. So what you are trying to do is to compare the information a mic placed in the normal listening position would pick up from: (a) a live musician in the room, and (b) a recording in which the image location of the musician is in the same place as the live musician in (a). And the reason for the anechoic chamber recording is so that you have a "pure" instrument/singer sound to play back which contains no room information, just as the sound made by the instrument/singer in a real room contains no room information at the precise instant it is produced. Yes, it would be a very interesting comparison but I'm not sure it's quite as valid as it appears. After all, we never hear that "pure" sound since we always musicians in a space with acoustic properties and that's the case in a recording studio as well so I'm not sure it's a good comparison to make. Also, is it possible to judge the "virtual location" of a recorded musician in the room accurately enough to place the real musician or instrument there? I can judge their direction from the listening seat quite well, but I find the virtual depth tricky. It's almost as if the recording overlays another space over the room and I don't have the reference points required to judge depth in that space. Different speakers portray space and depth differently as well, though the angular location of where things are in the left to right dimension is usually more consistent across speakers. I wonder whether the difference might not, in part, derive from the fact that there is always room acoustic information on our recordings and then our own room adds another set of such information and the two different sets of acoustic information "clash" in a way which is never heard when listening to live music. I would think there has to be something distinguishable when the recording, for example, contains information indicating that the performers are placed in a large concert hall and the listening room acoustic is telling you that you're in a 13' x 17' x 8' space with an alcove opening off it behind you and a large open doorway on the right side (my room). That kind of "location acoustic" confusion never occurs in real life. It doesn't have to be an audible artifact that is produced - simply having the 2 sets of information presented simultaneously should be enough to cause a level of confusion as to space that isn't present at a live performance and that may well be enought to tip us off. It's also interesting to consider that the scale of this problem will vary depending on the difference between the size and acoustic of the performance space and your own room, so the effect should be more pronounced on some recordings than others. I find symphonic recordings among the worst simply because the space difference is so large and I know there's no way an orchestra can fit into my room, so the scale is always way off for both the acoustic space and the people space occupied by the performers. It never seems as bad with a performance of one or two musicians, even if they're recorded in a live venue much larger than my room, because the scale of the performers seems more appropriate even though the acoustic space seems "off", especially when there's audience noise like applause. Then there's always the issue of whether your speakers can reproduce the full frequency range and dynamic range of a live instrument. While there are some which can probably do this for a piano, given the bottom note on a piano is around 28 Hz most speakers will fail that and the tendency of speakers to compress dynamics at high volume means many fail there as well. Things will definitely get worse there too as you add more and more musicians. No doubt someone like JJ can come up with a lot more differences between the live event and the reproduced, but I think we have a fairly good handle on what the differences are and I don't think that we can eliminate them all with better equipment and room correction. Frankly, I'm staggered at times at how good a job we can do at reproducing music. When you stop to think about it, it does seem rather implausible that you can produce the illusion of a musical performance in your room out of the bits and pieces that go into our systems, doesn't it? David Aiken
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