The Nebbiolo uses a pair of Seas CA18RNX, the Hiquophon OW1, and a Tang-Band W4-1320SJ. It targets second order Linkwitz-Riley slopes and takes cues from a Duelund approach, with the midrange being a fill – with these slopes, thats still a pretty broad range it has to cover! Targets held over the first 12dB on all the drivers but shifted to a slightly higher slope in a couple cases.
Impedance remains benign, though the impedance peaks around tuning do run into the woofer inductor inducing a minor bump. It’s still a 4ohm nominal design – unavoidable entirely with this set of drivers.
Parts count is, I am sure, higher than many people want to see – especially for a 2nd order design. However, to keep it clean and maintain good phase alignment… note that this has more components for impedance compensation than for the crossover! I tried lots of variations,and some changes are less audible than others. Tweeter Fs management is really about phase, and many people may be happy leaving it out. The zobel allowed a different cap, and was a very audibly improved presentation – I did not use it initially!
The gallery contains some early models – though they’re close enough I didn’t re-model the off-axis plots once I was done tweaking. The extremely smooth (and still very very flat) off-axis response is worth noting here – out to 45° off-axis.
