Cabinet for 2-way ported loudspeaker

thingiverse

This is an untested design for a high fidelity 2-way loudspeaker. The concept revolves around cabinet rigidity and the avoidance of bass or midrange resonances, which are crucial for sound quality. However, thick, heavy cabinets aren't practical for 3D printing, so this design employs a "matrix" structure inside to provide overall rigidity while moving vibrational modes to higher frequencies. A matrix structure is similar to 'infill' on a 3D print but more sparse since sufficient internal air volume is necessary for a loudspeaker bass cabinet. The top struts of the matrix structure, when printing with the baffle face down, are arced to facilitate bridging during the printing process. Supports should be used from the bed surface only to assist with overhangs in the driver area. A section of the matrix structure has been removed at the back to accommodate a crossover network. If this design is ever built, I'll install a door on the back panel for a crossover board and speaker binding post connectors, but I'll wait to see what the crossover requires before doing so. This design utilizes an Anarchy 554 woofer (https://www.diysoundgroup.com/speaker-parts/speaker-components/woofers/anarchy55-4ohm.html) and a Tectonic TEBM46C20N-4B BMR-type tweeter (https://www.parts-express.com/tectonic-tebm46c20n-4b-bmr-3-full-range-speaker-4-ohm--297-2157). These drivers are not inexpensive, but they're still within a reasonable price range for a speaker design with high-end audio aspirations. Bass is projected (using WinISD software modeling) to be -3dB at 46Hz before room-lift, so it should reach an honest ~40Hz in-room. The Anarchy woofer has a lot of output capability for its size, making this speaker act much larger than its dimensions might suggest. The BMR tweeter boasts an unusually wide coverage angle and can be crossed over down at about 500Hz, resulting in good off-axis behavior and near point-source performance. However, this design hasn't been built yet, so no promises can be made about its actual performance. Additionally, without having drivers in a cabinet, no crossover network has been designed – it's still a work-in-progress. This speaker requires the full capacity of a 300mmx300mm (and 260mm high) printer, so ensure your endstops are carefully aligned. It will also consume more than 2.5 1kg spools of filament per cabinet and several days' printing time, which is one reason I haven't printed it yet. If anyone out there prints this speaker for a challenge, please post a photo here!