Laid back = a shallow broad dip in the midrange frequency response; whereas "up front" would indicate a broad peak in the midrange response. Even a mild rise or dip would be audible and manifested in the way you noted. Room reflections and cancellations can cause or exacerbate such effects too.
I believe the sonic holography thing had to do with electronically cancelling the interchannel crosstalk, which results in a very wide soundstage. If done perfectly, it would mimic a headphone's binaural presentation. Polk had some success with this as well. Neither method yielded perfect results but the effects were easy to hear.
You can also cancel interchannel crosstalk acoustically, by placing the front speakers about 3 feet apart and then putting a large acoustic barrier between them ( a mattress or door turned on its side would work) extending from the midpoint between the speakers to the listening position. You could position your head 6" back from the end of the acoustic barrier and listen. I heard such a demonstration of this effect and though the speakers are only 3 feet apart, they sound like they're more like 30 feet apart. Ralph Glasgal at ambiophonics.org has a lot of good info on this subject. Here's another link that gives further explanations and tells how to use a computer with a Soundblaster Live card to create a concert hall experience.
http://audio.muddle.de/
Enjoy!
I believe the sonic holography thing had to do with electronically cancelling the interchannel crosstalk, which results in a very wide soundstage. If done perfectly, it would mimic a headphone's binaural presentation. Polk had some success with this as well. Neither method yielded perfect results but the effects were easy to hear.
You can also cancel interchannel crosstalk acoustically, by placing the front speakers about 3 feet apart and then putting a large acoustic barrier between them ( a mattress or door turned on its side would work) extending from the midpoint between the speakers to the listening position. You could position your head 6" back from the end of the acoustic barrier and listen. I heard such a demonstration of this effect and though the speakers are only 3 feet apart, they sound like they're more like 30 feet apart. Ralph Glasgal at ambiophonics.org has a lot of good info on this subject. Here's another link that gives further explanations and tells how to use a computer with a Soundblaster Live card to create a concert hall experience.
http://audio.muddle.de/
Enjoy!