thought I would post some tidbits from that article on the crossover:
"The crossover is a third-order design that uses Audiocap 1% polypropylene metal-film capacitors and air-core inductors rated at 600 watts. Capacitors used in high-end products are often rated at 5% tolerance, and the inductors are sometimes ferrite-core types of lower power-handling capacity. Barnes plans to switch to MultiCap capacitors in the near future, and they are even more costly. The wiring, which is high-grade silver wire from Germany that’s hand-braided by nOrh to reduce inductive effects, is all hand-soldered using silver solder. The crossover is tuned using an LMS system, and the coils are positioned so that their flux is going in opposite directions.
With all this going for the nOrh 7.0, Barnes could have tried to cut corners in the area of driver selection -- but he didn’t! Instead he chose some of the very best units available to complete this package. A Scan-Speak 18W/8545 7" carbon-fiber woofer assumes the role of the baritone, and the Scan-Speak D2905/9300 1" silk-dome tweeter is the resident soprano. These same drivers are used in much more expensive speaker systems. To my knowledge the 7.0 is the least expensive speaker on the market to incorporate them.
The frequency response for the 7.0 speakers is stated as 45Hz to 36kHz +/- 3dB and -10dB at 33Hz. The rear port is tuned to 46Hz, and the internal cabinet volume is 17 liters. Sensitivity is 87dB for a 2.83 volt input at 1 meter, and the crossover frequency is set at 2kHz. Nominal impedance is specified at 8 ohms, and the minimum impedance is about 6.5 ohms at 200Hz. The two low-frequency impedance peaks occur at 80Hz (25 ohms) and at 20Hz (30 ohms). Except for the low-frequency impedance peaks, there are no other sharp peaks or dips that would suggest a difficult load for the amplifier."
So it seems that options for the speaker evolved a bit over the years but Tyson found the 9300 to be the best tweeter after all.