Sharing what I'm working on. I'm planning a Directiva r1 build with passive crossover and probably the -NAA aluminum cone driver. My box will be a bit different as well, so clearly I'll need to use my own measurements and change the crossover, but it helps to go through the process with existing data.
I took what
@ctrl provided
here and deleted the unused DXT dsp chain. Per
@ctrl's intentions (if I followed correctly) that provides corrections to Amir's NFS data as a baseline for crossover design.
The DXT part is what
@617 provided back at
post 5. (Note: Others have suggested that the DXT will benefit from a couple of parallel notches but that's another matter.)
The Purifi part uses the topology from the SPK16 app note, with the impedance network for the aluminum cone driver shorted out. I used Purifi's values as a starting point (crossover freq unspecified but similar?). Series resistance values of inductors included in optimization were inserted as separate components so they could be locked to reasonable approximate values. I then used VCAD's optimize function on the woofer network (other than inductor series resistance) and the tweeter series resistor. I re-checked inductor DCRs, adjusted to available values, and checked that there was little or no effect of any adjustment.
The
biggest inductor is big but manageable - 28 ml volume without subtracting for the air core. If using the aluminum cone version, notch filters per the Purifi app note would be recommended.
Seems promising.
EDIT - VCAD is showing huge power dissipation in R7. The topology is from Purifi (and doesn't seem at all unusual) though the component values are changed.
VCAD project attached.