"According to my Fusion 360 simulations, this cab structure is 8 x stiffer than MDF and 3.4 x stiffer than Birch ply of the same thickness. There's very little ringing, no flat internal surfaces and the geometry helps break up and diffuse internal standing waves. It's like taking out a whole flock of squawking geese with one stone.

"With external dimensions of 16 x 21 x 32cm WxDxH, the perfect mini monitor cabinet was born. Because of the massive motor and magnet on the Dayton driver, I printed an additional support ring to reinforce the front panel. Since space is tight and internal access limited, the crossover will mount to a 6mm stainless steel panel that screws into the rear of the cabinet.

"So what's the final result of combining a 150mm Dayton Epique with two 180mm passive radiators in a 7-liter mini monitor? A speaker that works beautifully on the desktop for work and play; or as a traditional bookshelf speaker. I'll let this graph do the talking for now. Measurements were taken in the 40m² Virtual HiFi listening studio. The black shows my standard listening position 3 metres from the speakers; the red line is 45° off axis." If Dayton as an OEM supplier was as yet unfamiliar, Wilson Audio's Loke subwoofer runs their 500-watt DSP-enabled plate amp.

At this juncture, my reader Mica checked in. "Whoa Srajan, your updated Viper piece really has me excited. Greg's enthusiasm for the project is totally palpable and with his track record at Cube and Qualio, our man clearly has mastered the dark arts of not just speaker design but driver design and driver manufacture. That makes his choices of Mundorf air-motion transformer and Dayton super woofer and passive radiators all the more inspired and far more promising than the average guy just starting out in a garage workshop. Working all of it into a wholly 3D-printed enclosure of that sophistication then takes the cake. Why do you think it is that such ingenuity so often comes from very small outfits not from the big established power players? Those tend to own the distribution and presence in the remaining High Street shops to get all the traction but it's this kind of thing that I find far more appealing and would love to see a lot more people find out about…"

I replied that "I think that a lot of true creatives are at odds with corporate structure and big business. It's not where they tend to end up because there they would work for shareholder profits and design by committee. That must be one big reason why a lot of ingenuity and resourcefulness can often be found far off the mainstream… A major brand whose opening order for a new model might squash what Greg will sell in a lifetime could probably not countenance spending five non-stop machine days to produce a single raw cab. How many 3D printers would they need to satisfy their global distribution partners? Sometimes being small and obscure has real advantages. You get to do things in ways you couldn't justify scaled up. In such cases, having the wisdom to remain small can be key." For Viper, being small definitely is key to its conceptual kingdom.