audible physics
an exercise in maximising small-scale acoustics, this prototype focuses on delivering a genuinely balanced sound with actual bass from a compact footprint. by pairing twin 5 watt 40mm drivers with 2 passive radiators (one on the rear for pressure equalisation), the enclosure handles a fair few of the lower frequencies with only some of the muddy distortion common in low-tier portable audio systems.
screenshot of the result (red line) of a frequency sweep measured by spectroid (1 meter away). click to enlarge.
despite the rolloff at 100HZ, when EQ in Android is set to the Harman curve the speaker is surprisingly competent, with a crisp room-filling sound that packs a modest punch for such a low bill of materials (£17)
power is delivered by a single usb-c rechargable 18650 lithium-ion cell with a 2200mah capacity, giving the speaker roughly 10 hours of runtime at about 60% volume. to maintain acoustic compliance and pressure seals during active testing, the unit is currently held together with industrial electrical tape at the seam. in future iterations i will implement machine screws with threaded inserts.
it's a rough, highly functional prototype: unapologetically utilitarian, but it proves out the physical architecture necessary for relatively rich sound generation before moving into refined enclosure iterations with EQ, DSP and other additions.