3DPrinting

I've seen that approach taken to make the enclosure more "dead", but at these power levels it doesn't really matter a lot. The walls are 1.8mm thick with 30% infill. The top and bottom are PETG and the middle section is ASA. These materials are more ductile than say PLA, so they're inherently slightly deader.

You're absolutely correct that the approach you suggested would result in a slightly better outcome for a bit more weight to lug around and a little more design effort. It just didn't seem worth it to me for this portable and fairly low power application.

Go for it! 3D printing unlocks the opportunity to easily fabricate things that would be pretty difficult to make out of only wood. I'm mulling over making a baby array of BMR drivers https://www.tectonicaudiolabs.com/audio-components/bmr-speakers/

Another commenter in here suggested filling the gap with concrete. I don't think it's worth it at this power level, cheapish BOM, etc. The enclosure is also ASA (the middle) and PETG (the top and bottom), so it's a bit more dead than PLA already.

That looks like an interesting design. If you're linking to something like that, you've heard of Hoffman's Iron Law already. I chose size and low end response over efficiency. I did model some higher order enclosures, but they either didn't get low enough (size, efficiency) or were too big (efficiency, low end response).

Thanks! There are two "big" details that I did think about to some extent.

The first big choice was what kind of enclosure type I wanted. This winds up running into Hoffman's Iron Law, which means choosing two: low end bass, efficiency, and size. I chose size and low end bass, which means that I went with a traditional ported enclosure. I did consider, and spent some time modeling, a more exotic double bass reflex enclosure, but it just wound up being too large. Modeling in this sense involves acoustic modeling, which I did in WinISD for the ported enclosure and Hornresp for the double bass reflex, and physical modeling, which I did in Fusion360. I also selected drivers that would play fairly well with one another.

The second was geared more toward printing. Curved surfaces resist flexing more than flat surfaces, so most everything is curved or has a reinforced (eg the top and bottom). I wanted to minimize the need for supports, so the ports have "built in" supports. There's also the tongue and groove thing for the top and bottom to minimize air leakage.

As far as the drivers without the enclosure, an enclosure adds two things:

• Low end extension. Woofers in free space have extremely limited bass response. In this sense an enclosure is good
• Diffraction and baffle step. This is part of the reason why the sides of the front baffle have a massive radius on them. In this sense an enclosure is bad

Or both, as the barrel jack is much more robust than the USB-C connector.

Laziness and easy BMS board compatibly, but I totally understand the sentiment. It's not like I can't print a new top if/when I discover an easy/drop in solution that deals with negotiating power and voltage.

Thanks!

Thanks! Hexibase's builds are super cool.

If by characterize them you mean measure the driver's t/s parameters you can do it with a multimeter, a resistor, and basically any amplifier using a computer to generate the frequency. Elliot can be a bit verbose, which makes his instructions somewhat hard to follow at times, but here's a guide: https://sound-au.com/tsp.htm

The top and bottom are PETG. The middle section is ASA. 0.6mm nozzle, 0.3mm layer height, 150% extrusion width, two perimeters and 30% infill. I was cruising, but did limit my max flow rate to 25 mm^3. I could have gone even faster, but I was in the rate of diminishing returns for print time. I printed it in my Voron, but it did need some extra insulation to get the chamber temp high enough to avoid warping. The print completing completely successfully told me it's possible to do big ASA prints with a 60 degree chamber temp, so I'll be spending the time to make some nice insulated ACM panels.

Thanks!