The resistor shelves the capacitor at some frequency *. Around this point and at higher frequencies the capacitive reactance is below 1 ohm and the resistor is effectively shorted. At lower frequencies, 1 ohm is added to what the 15uF capacitor is doing.
The 1uF capacitor almost looks to be unnecessary, but is likely making a subtle but wanted change in the response. Simulating would make this much easier to understand.
* [about 20kHz - 1/(2*pi*1*0.0000082)]
Here's a sim.
First off, here's our drivers : SB29RDNC-C000-4
$58 from Meniscus :
SB, SB29RDNC - Meniscus Audio
Eminence Beta-6A
$65 from PE :
Eminence Beta-6A 6-1/2" High Power Midbass Midrange Woofer Speaker
Side note: I don't know how they make a profit on these speakers. Even if you built these yourself, you're looking at nearly $700 for the midrange and tweeter array alone. The Internet says the speakers retail for $3000 a pair? That's a crazy price.
First off, here's what the circuity would look like with no xover filter whatsoever. This is the basic response you'd expect from a nice soft dome tweeter. 87dB efficiency, a F3 at 1200Hz and output to 20khz.
Here's the response with Tekton's seven element array. There's a series of things happening here:
First off, with a center-to-center spacing of about two inches, the array elements will begin to destructively interfere with each other at about 2khz
if they're all playing full range. That's a big IF; the whole point of this xover is to "power taper" the elements on the outside, similar to what D.B. Keele does with his CBT array. Only the center element is getting full power.
Instead of conventional power tapering, the Tekton array filters out the highs
but not the lows. This means that below 3khz, the seven element array is basically behaving as a single diaphragm that's approximately seven inches in diameter. This is nice because it narrows the directivity, similar to what a waveguide would do.
In the sim, you can see that the center driver (red) gets full power, the top and bottom tweeter (yellow) get approximately 100% as much power (each) and the outside tweeters get 25% as much power (each.)
The graph is a bit deceptive, because the yellow curve represents *one* tweeter, not two. IE, the combination of the two will be louder than the yellow curve suggests.
The most important part about the whole circuit, is that every tweeter is lowpassed except the tweeter in the center.
As if all of this wasn't confusing enough, the low pass filters on the outer elements do one more thing, which is that they CURVE the array. This is because the inductors introduce a delay. So the lowpass filters curve the array, just as if the baffle of the loudspeaker was curved. Curving the array should extend the highs and widen the beamwidth of the array.
All of this is fairly standard stuff if you've read up on the Keele CBT papers. Very similar idea.
In a nutshell, the Tekton speaker uses an array of seven tweeters to raise the on-axis efficiency to about 93dB. The tweeters hand off to an array of high efficiency prosound midranges. The net result should be a speaker that looks (fairly) conventional but has efficiency and directivity control that's similar to a horn. In a lot of ways, it's a two dimensional CBT array.
Here's some stuff that might help explain this speaker:
1) passive loudspeaker delay :
Passive Loudspeaker Delay