Ghostfather

I'm sold on the class D amps made by Orchard Audio, which use Gallium nitride transistors. The monoblock amps drive my LaScala clones using XLR inputs from an Orchard Audio streamer (using PCM1794A dacs) and Tidal. They also make stereo amps, all very budget friendly, and very clean sound. I find the sound better than the NAD integrated amp with Hypex UcD outputs that I was using, but it's also a class D amp.

I built my Eliptrac 400's from kits, and bought the Eliptrac HF, from Dave Harris. Very nice, but would have loved having them as Baltic Birch like these horns. Not getting rid of them, they sound great. Just out of curiosity, where can I find the formula's for designing horns as 3D ellipses, like these horns or the Eliptrac's, based on frequency distributions, and matching them to a specific driver? I have access to a CNC router to machine things like this, just need to generate the 3D model and slice it up.

I'm considering changing the plans to beef up the exterior panels to 25mm (1"), as well as the back panel with splitter and bottom panel. After reading here on the forum about bracing to reduce resonance of the 3/4" original panels, this seems prudent. I will probably keep the doghouse and woofer motorboard as 18mm (3/4"). Also, the La Scala II went with 1" MDF to reduce resonance as well. This will make the exterior of the whole speaker a bit bigger, but the proportions and basic look should be the same. My aim is to keep the interior dimensions the same as the original, for acoustic reasons, especially in the bass bin. The exterior matters less, even the H/F portion is not reliant on the dimensions for acoustics. I may have been mistaken on the cover sheet of my plans stating that the original 1963 La Scala was made of 5/8" plywood, as it seems it was 3/4" plywood. My excuses.

Just posted these plans yesterday elsewhere on the forum, a whole set of CAD drawings that you could give to a cabinet maker or to build yourself. It's metric (I live in the Netherlands), but has a few modifications such as 45 degree miters between the sides and top, and a back panel for the H/F section.The original was open in the back. The horizontal brace above the doghouse is slotted into the side panels of the speaker. There are even cut plans to get all the pieces out of 3 sheets of plywood, which takes a bit of planning. LaScala drawings metric.pdf