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Someone asked by DM for facet cutting templates, so here they are as .stl files. These are all from a Fusion model of the speaker that would take me some time to clean up. Some notes: These were made for the 1.5 inch thick stock that I used for my baffles. This is relevant where the jigs wrap...

Sort of a non-update... I had a workshop injury late last week from a workpiece on the router table kicking back and hitting my hand. I was setting up a lock miter bit using scrap Baltic birch. 13,000 rpm at 0.75" radius = kickback at 58 mph. Lessons: (1) Use sleds, rollers, featherboards, etc...

As I make some decisions about enclosure construction, I thought I'd share a few measurements that I took to guide me. Thanks to @tktran for learnings he's shared, as well as to @augerpro for things he's shared on his website. The prototype box is generic big box store 7-ply 3/4" nominal (18 mm...

All facets cut, on both baffles. This went very quickly with the 3D printed jigs. If you look at the pics above, you can see that for each facet I printed two pieces: the main piece that fits over the baffle blank leaving the portion to be cut off exposed (5th pic above), and the second, a...

The lower facets were an aesthetic choice made in concert with the people who will own these, supported by listening tests with the prototype. I'vm planning on chamfering the inside to make space for air flow, but not until finalizing mounting.

Yes - all limited to the aesthetics and woodworking front... Took a lot of time to decide on the baffle material: black cherry. The balance of the enclosure will probably be birch or cherry plywood stained black but that's not finalized. Located and purchased stock, cut baffle blanks Bought a...

Someone asked by DM for a drawing of the baffle, so here it is as .pdf and also as .dxf. Dimensions are in mm. All of the facet cut lines on the baffle face are 8 mm from their respective driver opening tangent lines. In the prototype, this dimension was more like 4 mm but we decided to allow...

Aesthetic decisions made last weekend: Keep the woofer-tweeter spacing as well as the baffle dimensions, but lower both drivers about an inch on the face. Keep what we're calling full faceting: sides (tangent to the drivers) and center on both top and bottom Absent any new revelations, baffle...

Thanks! I will take a look. My attention definitely could have drifted away from the impedance chart. I've done a lot of optimizing in VCAD with the minimum set to 3.2 but maybe a bit higher is better and the optimization routine imposes a penalty for going below, not an absolute guarantee...

I'm prepping for a listening test in the "customers'" apartment. Here's a 3.5ms window response compared with the VCAD prediction (so ignore below 300 Hz). This is with 1/6 octave smoothing. The crossover is a DSP-implemented LR4 @2200 Hz. The Purifi LP is 2nd order Butterworth and the Purifi HP...

Measurements are complete, and checked (and corrected for) any change in microphone distance after repositioning on the stand for horizontal and vertical measurement sets or for alignment with the driver axes. 2D baffle simulation suggested that the baffle step would move up a bit in frequency...

Bottom facets are cut, and edges are aggressively rounded. Rounding was limited by the 3-5 mm distance from facet lines to driver openings, and I don't think it will have a major effect on the measured responses. I do expect effects - the baffle step peak moving a bit up in frequency and being...

Thanks, @fluid. ...which is what I failed to do when taking the measurements, by setting the delay in REW to a bit less than what corresponded to the distance. You end up with excess phase proportional to frequency, but with that same excess added to both drivers' responses. ...which was done...

[edits below for clarity] I think that what you're saying is spot on with regard to the acoustic center (approximating it as a fixed point). I set the delay in REW to just a bit less than what corresponded to the actual distance, and accordingly the impulse clearly begins a bit (about 88 us)...

Thanks again, @XMechanik, for noting the phase wraps. I'd set my measurement delay to be a bit less than what corresponded to the actual distance. Below, and in the attached, the merge is re-done, matching phase at the transition, and rather than apply correction to every sweep in REW I've set...

Thanks for pointing this out. Here's the phase with far field measurements only (They're in the .zip, in the Purifi folder.). Looking back at the VCAD Merge tool project, the merge frequency was set to 400 but the near field delay was zero. I had to change the frequency to something else to...

@Rick Sykora - this thread, and the thread on lobing linked there, were helpful. I also got a lot from this tutorial from Sausalito Audio. Happily, there's consistency (+/- full agreement) among the Sausalito tutorial, Kimmo's comments in the threads, and Dennis Murphy's comments. Anyway...

A question: Many of the crossovers that have been posted leave a 5 dB or so bump in vertical ERDI, in a 1-2.5 KHz range around the crossover point. Is this a concern? In what I posted above, I was working to avoid it.

A parallel notch (in my vernacular, band reject) in place of one of the series notches (in my vernacular, trap filter) tames the impedance significantly and vastly improves power handling. There's a Purifi app note where they do this for similar reasons. Vertical ERDI could be smoother, the...

Yep. VCAD is showing under 2 ohms and optimization brings it back down even though I have a max impedance specified. I agree here as well. When I was playing with passive crossovers for r1, there were some approaches with significantly lower component count, though involving much larger...