I am glad you asked.
Well the short answer, because according to Roger (the criteria for the driver selection in the short/mid/far field speaker design process) could take up to a week to explain, is:
They are 2 different technologies the lt-8 ribbon pushes the air in a way more optimal to the near field conditions of the surround channels of a small screening room. Let's call it near field "sound blooming point".
The air motion tweeter Squeezes the air out much farther out to a 4-5 meter "sound blooming point", and beyond. IOW if you had a large cinema he would use air motion transducers throughout on all channels.
Roger required front channel technology that would not blow up as he found out happened when in Hollywood they took his dome based Music Scoring monitors and then tried to implement them in Mixing Theaters.
In addition to punch through a perforated screen requires that narrower dispersion and focused power. So the selection of drivers is based on achieving a system that holistically integrates well together. He found out that tonally the LT-8 ribbon's "blooming point" (my term) when used in the surround near-field position does match more closer to the Air Motion transducer's timbre whilst the AMT are at the mid far field position, than the domes. So he tested dome tweeters for the surround channels and he could not get them to integrate as well with the front amt's. The ribbons where engineered to look similar to the amt as an industrial design consistency. That part worked, the fact that there were two different tweeter technologies flew under my radar, until you asked just now. That is why am glad you asked.
I am so jaded over the years with the surround sound options out there, dynaudio blow ups, meridian tweeter blowups. genelec/procella boxiness, horn harshness, etc. and etc. that when I went in with Quested I was very skeptical. Once I heard the results I have been floored. I can 100% confirm that Rogers driver design decisions do yield a superior loudspeaker surround system that in an imperfect world steam rolls over anything else out there.
I know many consider me as the best video guy (can't say i blame you there
), yet I have not necessarily been known to be a top audio guru, yet my instincts in multi-channel sound did not prove me wrong, and let's face it , my contempt for 2 channel audiophilia and faith that there was light at the end of the multi-channel tunnel have paid off. Since age 19 then as a musician I have been pursuing multi-channel nirvana, it has been an unnecessarily bumpy road, I believe the incredible results at Albiorix have placed me atop the multi-channel systems designer/installer's heap, I submit that it was not all random luck as some may assume, but instead submit that this is the end result of perhaps a good trained ear and focused due diligence (one that the entire global battalion of home theater apparatchiks could not even come close to conceive). I instinctively picked up on a sound track: DESPICABLE ME: FUN FUN FUN and I reverse tracked back to Quested and requested that same mastering room near field performance but at a far field. It is brilliant! I know. So I do take full credit - thank you, If I can blow my horn a bit
Having access to every high end brand out there, for precision, realistic, synergistic high end screening room multi-channel there is simply no other option, diamond coated woofers set aside. But the fun just starts, the best part is that Quested +Atmos is going to be the 21st century standard for quality sound at home or public venue.
Jeff regarding your question, now knowing what I have learned that I am not sure that there is much benefit to listening to the lt-8's at front channel positions if say over 2-3 meters away, it is simply not the right speaker for it , you would need the lt-10's. When you listen to the lt-8's do so in the surround positions for which the speaker is made.
Cheers!Edited by CINERAMAX - 12/16/13 at 8:18am