Re: Listening Get Together
Hi Leland or Doug,
Looking at the youtube videos, a couple of questions...
1) The "dual 18 test prototype model 218SLVX" cabinet in the one video shows rear facing drivers which are presumably firing into a reasonably long pathway. Typically when creating this sort of design, were I the designer, my goal would be to locate the drivers such that the output from the front and the rear of the driver could arrive simultaneously and in phase with each other in order to sum for increased output. It would seem to me that the configuration shown might be capable of significant output, but that multiple arrivals and a long path might negatively affect punch and usability in the higher end of the output spectrum (ie above 100hz). I am sure the designers have their reasoning for such a configuration, but I am curious.
2) The "LC8 Line Array PA Top" has a rear facing HF driver loaded into the "Vortex Waveguide", which presumably does some gymnastics with the audio passing through it (at the very least turning it 180deg). I have experimented with curved horns and found "smear" (low tech talk for multiple arrivals) to be evident even into the low midrange with such configurations, getting progressively more noticeable as the frequency rises. I can appreciate that BigE says that they are overcoming some traditional perceptions, but I would be interested to hear a more detailed account as to how this issue is addressed. The descriptions on the website of an "event horizon" are pretty vague, invoking reference to quantum mechanics and theoretical physics concepts. What does this waveguide actually look like? Are they actually making a real physics claim, or is this just marketing? For those reading along:
http://en.wikipedia.org/wiki/Event_horizon
http://relativity.livingreviews.org/Articles/lrr-2005-12/fulltext.html
From BigE - "transmit auditory information beyond line of sight with minimal loss. The Vortex Event Horizon will wrap around objects, obstructions, and up to boundaries providing a self-adjusting nature to the nearfield."
I am curious as well regarding how the above claim might impact reflection and especally further information regarding diffraction properties, which are commonly known to be frequency dependent, ie d sin(theta) = m lambda for nerds. If you have actually overcome the diffraction equation you will stir waves in the science community. And how could you derive a coverage pattern in this case?
Please don't take this post the wrong way, I am legitimately curious as to the responses to these questions.
Cheers
Jeff
