> It seems that the unit with the unusual size of 160 cm had a lot of difficulty in the characteristic test. At the Koriyama Test at the Koriyama Factory was carried out in the measurement room at first, but it was stopped because fluorescent lamps on the ceiling fell due to vibration. It seems that the characteristic test was carried out at the ground in the factory premises.

> The outdoor test seemed to have a negative impact on the neighborhood. At a distance of about 100m from the speaker, it was felt as sound, but at a distance of more than that, it was transmitted as vibration and earth rumbling instead of audible sound. Within a radius of 2 km from the factory, there were damages such as vibrations like earthquakes and earth rumbling, and sound of walls and windows.

Very sceptical that a 3kW speaker can cause "earthquake like vibrations with a radius of 2km".

wowie

"The Hitch Hiker's Guide to the Galaxy notes that Disaster Area, a plutonium rock band from the Gagrakacka Mind Zones, are generally held to be not only the loudest rock band in the Galaxy, but in fact the loudest noise of any kind at all. Regular concert goers judge that the best sound balance is usually to be heard from within large concrete bunkers some thirty-seven miles from the stage, whilst the musicians themselves play their instruments by remote control from within a heavily insulated spaceship which stays in orbit around the planet - or more frequently around a completely different planet. [...] Many worlds have now banned their act altogether, sometimes for artistic reasons, but most commonly because the band's public address system contravenes local strategic arms limitations treaties."

(The Restaurant at the End of the Universe, Douglas Adams)

Is the article itself written by the manufacturer or a 3rd party? It keeps saying "we ..." but then also "[i]t seems that ...".

Edit: apparently the site is translated from its original Japanese version, which explains these weird wordings.

The original article is here, which has more pictures too: https://audio-heritage.jp/DIATONE/diatonesp/d-160.html

For many many years I have kept a design file on a subwoofer which would be far larger than this. 3kW is jack crap. The subwoofer I have in the trunk of my daily driver is almost 1kW. I’m thinking more like 95 KVA, or 76kW at an assumed 0.8 power factor. 3” cone displacement and 18,000 LbF available to drive the cone. Low pass filtered at 2000 hz. I am entertaining all offers from our resident billionaires to quit my job at the jet building factory to create such a device. We can drag it to Burning Man. Our first capex will be this big ol electrodynamic shaker head.

https://www.udco.com/products/electrodynamic-shaker-systems/...

Can only imagine the power efficiency of this was horrible.

Don’t they use something like this on ships to fend off pirates who want to board?

The claims sound somewhat exaggerated, 5kw of subwoofer is nothing in live music venues, though they purposely don’t go as low. Here’s some more modern “big” subs, which are larger and can radiate significantly more power

https://www.aia-cinema.com/products/the64-sub-pro-passive-se...

https://www.aia-cinema.com/products/the100-sub-pro-passive-s...

160cm is ridiculous. There is no advantage to this over multiple drivers in the same size enclosure. You'll get significantly lower distortion with an array of smaller units. The rigidity of the speaker cone is a big deal. Smaller ones are easier to make stiffer.