This really hertz

September 28, 2006 5:59 PM

20Hz not low enough for you? Aching for 5Hz notes? You need the rotary woofer.
posted by mr_crash_davis (36 comments total)

Huh. But can you install it in a Civic?
posted by cortex at 6:10 PM on September 28, 2006

cortex, more importantly can you use it for propulsion?
posted by aubilenon at 6:11 PM on September 28, 2006

"The Thigpen Rotary Woofer is the worlds first true infrasonic home audio or home theater woofer."

Actually, that's not correct.

I used to work for an acoustical consultant that had a sub woofer called a Ling Shaker. Its frequency response was from DC - 20Hz, and the output was measured in Gs.

It came with it's own 1000 watt amp (which had no output above 1K).

The thing was fucking amazing.
posted by Relay at 6:18 PM on September 28, 2006

Somewhere in between 7 and 9 Hz is the legendary "brown note" - under the influence of which it is apparently impossible to control your bowels. I need one of these things to hit that at shows.
posted by BlackLeotardFront at 6:23 PM on September 28, 2006

The whole helicopter-blade-variation-in-angle-of-attack-creating-variations-in-air-density-and-thus-sound approach is pretty ingenious, though.
posted by ChasFile at 6:27 PM on September 28, 2006

a sub woofer called a Ling Shaker

I worked for an oilfield instrumentation company that had one of these. I swear you felt like your skull was going to fly apart when they swept the thing up from DC to 40 Hz over the course of 5 minutes.
posted by ZenMasterThis at 6:31 PM on September 28, 2006

I'll save you the trouble of digging around for the punchline:

Total $21,950-$25,950
posted by nanojath at 6:33 PM on September 28, 2006

But can you install it in a Civic?

"the model 17 must be professionally installed in an attic or basement which becomes an infinite baffle."

My guess would be no. It sounds like it just shakes the house a bit.
posted by Balisong at 6:39 PM on September 28, 2006

I worked for an oilfield instrumentation company that had one of these. I swear you felt like your skull was going to fly apart when they swept the thing up from DC to 40 Hz over the course of 5 minutes.

ZenMaster: What are these things used for, seriously? (If it's to blow skulls apart, cool).
posted by KevinSkomsvold at 6:44 PM on September 28, 2006

The part where they say it has response to DC is bullshit. It's not a vacuum pump or a pressure chamber.
posted by TheOnlyCoolTim at 6:54 PM on September 28, 2006

TheOnlyCoolTim: It's a fan, which is basically a vacuum pump.
posted by aubilenon at 6:57 PM on September 28, 2006

Apropos of the Brown Note: asavage might have something to say his experience of it since Mythbusters covered it once. The interesting effect was how many people felt discomfort from the low-end sounds.
posted by John Shaft at 6:58 PM on September 28, 2006

i've seen some (vague at best) research that suggests hitting the resonant frequency of the chest cavity or particular organs can incapicate and potentially kill people. it may take rediculously high amplitudes or long exposure times to do serious damage, but with this one might be able to cause headaches, nausea, and other such mischief. now, for some time i've been planning on starting a "band" with the sole purpose of landing a big gig and attempting to clear out the place with a throbbing gristle style assault, but with this baby and a little experimentation i might actually be able to make people flee from physical discomfort.
posted by waxboy at 6:59 PM on September 28, 2006

I remain unconvinced by MythBusters' take on the brown note. (sorry, asavage!)

I realize they had a sound tech out there, but those speakers and amps, as well as the inward-firing cylinder didn't look like a good way to test for the "brown note".

Having worked on some really, really large and well done sound systems (20-50kW in amps, tri-amped, dozens of bass cabinets pushing dual 18" cones, dozens of mid/top cabs.)

I've personally felt the beginnings of the "brown note" in the form of a digitally controlled analog synth sound-testing a large system as described above.

Really, I damn near crapped my pants. I had to go (ab)use a porta-potty immediately. I've also had the wind just knocked out of me and have experienced heart palpitations and other bodily effects above and beyond the ordinary "hey, that tickles!"
posted by loquacious at 7:01 PM on September 28, 2006

Well, if it can produce a signal at 7 Hz, it will make you nauseous.

Plus, sounds below around 15-20 Hz are inaudible anyway. All this thing would do is make your house vibrate and make you feel sick.

I'll pass.
posted by MythMaker at 7:07 PM on September 28, 2006

I need to ask the girl in the apartment underneath me if installation would inconvenience her in any way.
posted by pwedza at 7:31 PM on September 28, 2006

They make a computer speaker too.
posted by hortense at 7:57 PM on September 28, 2006

What are these things used for, seriously? (KevinSkomsvold)

Ling and other shaker tables are used a lot for testing equipment. You find out right quick where weak points are. You can sweep a simple (sine) waveform from low to high and at certain frequencies things will start to flop around. The wires under your dashboard are one example of that. You can also put a stew of frequencies (random vibration) into the mix. The shaker will make a roaring noise when you do this.

At 50 G rms random vibration you can't stand to be in the room with the shaker. Some pieces of equipment will thrash themselves to bits under conditions like these. I have poured powdered aluminum eroded from the enclosures of more than one bad design that got tested this way.
posted by jet_silver at 8:03 PM on September 28, 2006

Over the years the generally accepted low frequency limit of hearing has been 20Hz, some suggesting 16Hz. However nothing existed to produce significant enough output to change this belief. This development will spawn new special effects and we will begin to understand the true low frequency limit of human hearing.

That's a bit silly, of course you can generate frequencies lower then that. This sounds like audiophile snake oil to me. Of course, you can definitely feel notes that low.
posted by delmoi at 8:17 PM on September 28, 2006

For the man with the $485 wooden knob.
posted by weapons-grade pandemonium at 8:24 PM on September 28, 2006

maybe we can use it to talk with elephants. (5 - 30 hz).
posted by MonkeySaltedNuts at 9:58 PM on September 28, 2006

Just across the street from our own bjork24's Moxie Cinema there is a custom shop/studio where a gentleman is currently building a 15 foot woofer. It looks real impressive and I hope he lets me play one of my basses through it.

Kinda like the opening to Back To The Future.
posted by sourwookie at 10:06 PM on September 28, 2006

What Jet_Silver said.

Essentially, a big part of acoustical consulting is applying vabrational loads to structures to see where they fall apart, or, seeing where the vibration is present (which frequency), and then damping that frequency (e.g. to get rid of annoying noises in AC duct work).

(Hey, and what happened to spell check?)
posted by Relay at 10:19 PM on September 28, 2006

I can't believe this has come up twice in as many days, but this would be perfect for a Feraliminal Lycanthropizer.
posted by quite unimportant at 10:40 PM on September 28, 2006

The wavelength of a 20 Hz wave in air is something like 56 feet. So if your listening room is bigger than that in any dimension, go for it. Otherwise, enjoy your standing waves and cancellations.
posted by paulsc at 10:49 PM on September 28, 2006

i have near no idea what the hell it is you people are talking about.
posted by punkbitch at 11:47 PM on September 28, 2006

I want one.
posted by caddis at 12:10 AM on September 29, 2006

So, this subwoofer... it rotates?
posted by neckro23 at 12:31 AM on September 29, 2006

Nah, it just blows.
posted by eriko at 5:13 AM on September 29, 2006

Metafilter: heart palpitations and other bodily effects above and beyond the ordinary "hey, that tickles!"
posted by AwkwardPause at 5:33 AM on September 29, 2006

Sitting here next to a 200lb 1000 watt subwoofer, I can vouch for the added dimension of having your pants leg flapping to the music.

Its true, as paulsc says, that it's only really musical outdoors or in a very large, solid space. Otherwise, sweeping those low frequecies just changes were in the room the rattling sound is coming from.
posted by StickyCarpet at 6:08 AM on September 29, 2006

I try and imagine the effect, and all i keep thinking of is wind. slow, incredibly expensive wind.
posted by phylum sinter at 7:39 AM on September 29, 2006

Thanks Jet Silver. Very interesting.
posted by KevinSkomsvold at 8:21 AM on September 29, 2006

Audiophiles are amusing creatures, aren't they?
posted by rocket88 at 10:52 AM on September 29, 2006

I read the wikipedia article and another on the brown note (interestingly, after i made my post and before all yours :) ), and I too am unconvinced. They tried exactly 5, 7, and 9Hz only, which is entirely inadequate when you are searching for a specific resonant frequency, which is what the brown note purportedly is. If they had started at 5 and stepped up by a tenth of a Hz every minute or something (hopefully taking a break every 10) I would be more convinced.
posted by BlackLeotardFront at 11:20 AM on September 29, 2006

We had this in 1974 - Specifically developed by Universal Studios sound engineers W. O. Watson and Richard Stumpf for the theatrical release of "Earthquake," Sensurround essentially created subsonic, low-frequency vibrations between 5 and 40 cycles at sound pressures of 110-120 decibels...
posted by Lanark at 2:31 PM on September 29, 2006