At some point in the mid-1980s, a group of Mitsubishi engineers looked at the laws of physics, nodded politely, and decided to ignore them. The result? The Diatone D-160, a subwoofer so comically overbuilt it makes a monster truck look like a Hot Wheels car.

Let’s get the absurdity out of the way: this thing is 1.6 meters across. That’s 63 inches. That’s taller than Danny DeVito. The cone alone, designated the PW-1600, weighs about 3 kilograms and is made of an aluminum honeycomb core wrapped in carbon-fiber-reinforced plastic. Because obviously, when you’re making a subwoofer the size of a manhole cover, you want to keep it light.

The magnet? A 400-kilogram field coil motor, because using a permanent magnet would have required 800 kilograms of material and perhaps a deal with the devil. The frame? Another casual 600 kilograms. Altogether, the enclosure tips the scales at around 1.5 tonnes. This isn’t a speaker. It’s a siege weapon.

It could hit frequencies as low as 8 Hz, which is well below what humans can hear but comfortably within the range of what humans can feel — usually moments before their ceiling lights shatter and the dog runs away. During testing, the D-160 reportedly caused rumbling sensations up to 2 kilometers away. People described it as a “small earthquake,” which is a charming euphemism for “why are the walls vibrating and why is Nana crying?”

It wasn’t for living rooms. This beast was built for seismic research, industrial labs, and the kind of audio enthusiast who thinks “practicality” is just another word for “cowardice.” It debuted in Kobe in 1981 and later turned up in universities and power research institutes, where it spent its time proving that science and madness are sometimes indistinguishable.

There was even a Japanese quiz show that asked whether it could break prefab house windows. (Spoiler: it could, and did, because of course it did.)

The D-160 cost about ¥30 million back in the day, which is roughly the GDP of a small village. Each one took four months to build, presumably by a team of engineers, blacksmiths, and at least one wizard. Mitsubishi never mass-produced it, because even in the 80s, there was a limit to how ridiculous a consumer product could be before someone from accounting intervened.

And yet, here we are, decades later, still talking about it. Not because it was sensible or scalable or even remotely necessary. But because it was magnificent. The D-160 wasn’t a subwoofer. It was a flex. A rolling boulder of audio arrogance that dared to ask, “What if bass, but too much?”

It remains the largest single-driver subwoofer ever built. Others have tried to make bigger systems, sure—stacks of smaller drivers crammed into shipping containers, for instance. But none had the audacity to just make one enormous cone and call it a day.

The Diatone D-160 is proof that sometimes, the most beautiful words in engineering are: “Because we could.”