Specimen Audio – Finished! Janus Horn Ceiling-Mounted Spinning Speaker

One day about a year ago I received a call from Jack White. He inquired about a Janus spinning double horn speaker. He said that he wanted me to turn it upside down and hang it from the ceiling. After a long pause, I said it would take a little engineering. He suggested I embark on the project.

Below is more detailed information about the building of this newest Specimen including photos and a slide show of images taken during the building process. You can see more images of the finished Specimen here.

Original Janus Double Spinning Horn SpeakerCeiling-Mounted Janus Double Spinning Horn SpeakerWell it did take a little engineering, quite a bit actually. I quickly realized that not only was I grappling with the typical rotational forces, I was now defying gravity right above people’s heads. The prospect of a sharp-edged spinning projectile hurtling through space and chopping off someone’s head was terrifying to say the least.

To ease my conscience, I decided to fabricate all the support structures from half-inch steel plate instead of the aluminum I used on my other models.

Posing another engineering challenge was the diameter of the shaft. The Janus Horn Speaker features a half-inch shaft which is appropriate for the horn throat diameter, but I needed to drill through it and install a cotter pin of some description in order to hang it safely. My other Janus Spinning Horn Speakers rely on gravity to seat the bearings, instead of having to defy it and hang. Half-inch was the maximum diameter I could use for the shaft. Any larger than would obstruct the sound passing through the horn’s throat diameter. What to do?

After quite a bit of research I decided that key-less bushings were the way to go. One of them properly torqued is good for eight hundred pounds of thrust. If I added a backup bushing in case of failure, I felt reassured enough to go with it. With this stumbling block out of the way it was time to solve some aesthetic issues.

I was having a fundamental difficulty with the idea of simply inverting the Original Janus Horn because mounting a box on the ceiling just didn’t seem right. Coincidentally, I had started doing research on ceiling fans for my living room. After looking at scads of nasty designer fans I settled on the Hunter Original— a heavy industrial-looking fan with oil bath bearings. Very impressive. Then it hit me. Of course! The enclosure for the Specimen Ceiling Horn would be cylindrical. I made a cylindrical form out of laminated MDF and used 1/8″ thick bending plywood to create a custom 3/4″-thick cylinder. Once this was done I was on a roll.

At one point, I had mentioned to Jack that a cable controller might be a little awkward coming down from the ceiling and that I could look into a wireless system with a handheld controller. Careful what you wish for! Luckily, Blaise Barton from Joyride Recording Studio has expertise in such matters and made me a custom transmitter and controller. In spite of its ultra modern, etched board, surface mount, micro processor technology (essentially the opposite of the Specimen ethos), the unit has worked flawlessly and is a wonder to behold. I am very happy to have it on board (pun intended).

After installing the transmitter, circuit board, motor, fittings, and silver-foil backed sound-deadening material, the inside of the Ceiling Janus was really starting to look a little like the lunar module.

Instead of relying on wood screws alone to attach hanging components, I used long, 1/2″-13 stainless steel bolts running up through the whole assembly. This ensures that the unit will continue to defy gravity.

The threaded rod and clevis used to mount the unit to the ceiling was not visually inspiring, so I embarked on a modular carapace to enclose the whole upper unit. A bit of whimsy here resulted in a rather interesting onion dome. Following the format of the octagon, I created a single section of the carapace carved out of wood. I then made a mold of this and layed up epoxy into it. Repeating this process seven more times produced all the sections for the carapace. These eight sections were glued together and lacquered in alternating black and white colors.

One of the last steps was to install portholes around the cylindrical main body. I decided to use screens normally found on National/Dobro guitars and swaged them to hug the radius of the cylinder. This allowed for ventilation and I thought it might assist with the telemetry.

Last week, we delivered the Ceiling-Mounted Janus and successfully installed it in its new home. For having just a six-inch speaker, the Ceiling Janus sounds like a psychedelic Twin Reverb! It is a wonder to listen to.