Directional dual acoustics

greetings all, I realy like to learn every aspect of design and acoustics and got my self a book about studio design and acoustics. I think i realy understand some of the most important aspects now. BUT.... the last few days i read things like directional dual acoustics and i love to understand this way of working and the ideas behind it The story The books mentioned a person called Wolfgang W. Jensen. It is somewhere in the 1970's . He designed a room which uses SAWTOOTH absorbers which tended to absorb much of the incident wave from the loudspeakers but at the same time kept the room alive ( from the engineers point of view ) The idea * so i understand that by facing the acoustic openings towards the loudspeakers, the direct wave can not bounce back from the wall but got trapped inside the sawtooths and got heavely damped before it comes out again ( Is it ? or does it not come out at all ? ) * the reflective side of the sawtooth is faced towards the engineers. tend to reflect back their voices while they speak to each other, making the room less death for speach * It also is mentioned that the reflected faces are relative lightweight so that they also act as low frequency absorbers. * further it is mentioned that is this type of rooms the loudspeakers are build in the wall ( flush-mounted ) This type of room intrests me very much but sadly the information stops here . I tryed to found more information on the net by using google. I can not seem to find it :( I'm not able to find the right person , Wolfgang W Jensen. Is their some one on this discussionboard how knows how this type of room works ? Are their formulas to calulate this type of wall ? ( offcourse their are, but i mean is it using the same formulas or are special ones needed. How big do these wall need to be and what type of construction is needed. I know it is a big post but i hope someone here can help me with this :) Many thanx in advance Chris

here's an idea: http://www.johnlsayers.com/phpBB2/viewt ... 5986#75986

Thank you for posting that link. I hope i find what i'm looking for in that topic. ( going to read it now ) I'll let you know greetings