Infrasound...

[Piotr]

http://asia.reuters.com/newsArticle.jht ... ID=3401200

[Shawn Simmons]

I still think my studio is haunted. Maybe it's the iguanas.

How's the studio going Piotr?

It's me Shawn up in Seattle.

[YOUR KONG]

Didn't the Flaming Lips use ultra-low frequencies on that four-CDs-to-be-played simultaneously jobby?

Here's a neat Fortean Times article about sonic weapons that gets into this sort of thing. Cool story about a scientist whose laboratory* was suddenly "haunted" - he discovered that a newly-installed fan was humming at 18.9 Hz...

19 Hz creates hallucinations -- because it *makes your eyeballs vibrate!* Whoa!


* initially typed "studio..."

[Bony Thompson]

here's something cool:

http://www.reuters.com/newsArticle.jhtm ... ID=3414356

[Piotr]

I just posted that same black hole article on the top page.

Hey Shawn!!

Things are alright. I have three clients at the same time! I'm working on a pretty creative web drama that will be posted in the months ahead by a Portland couple. I've got a blues-rock band from Eugene off and on. And I've got a young guy producing an even younger vocalist for a reputable producer. So I'm active.

I had a great time managing the stage over at the Holocene here in Portland for MusicfestNW.

How are things for you? How's Matt?

[Professor]

There is a frequency that I believe is called the 'Helmholtz Frequency' though I may be mistaken that is the name for the resonant frequency of the earth. Normally the frequency lives down in the 7.5Hz range though it varies all over the world. In areas where the frequency is highest (upwards of 12-13Hz) people have the notoriously worst health and highest diease rate - India, for example. In areas where the frequency is lowest, people have the best health - Scandinavia, and other areas.

I think it is fairly common knowledge that the US Navy talks to its submarine fleet through the ELF transmitter (Extremely Low Frequency) that is setup in Wisconsin (or thereabouts) and transmits a 4-5 Hz vibration into the earth that can be heard by submarines located anywhere on the planet.

There are also stories of ancient gongs from various places around the world that had extraordinary powers of healing or hurting. Obviously if you can identify a frequency at which the eyes vibrate, you can find the frequencies for the other organs of the body and effect them with sound. Mickey Hart talks about this a tiny bit in 'Drumming at the Edge of Magic' and I've always wanted to do some further research in the area though I haven't had much time to devote. Maybe I will look into it now that Iim working at a University.

And then I seem to recall that there is a group researching the possibility of using concentrated sound waves to target and explode bacteria and viruses as a way of treating diseases in the human body. For example, find the frequency at which the AIDS virus vibrates to explosion and 'spray' the patient's body with that frequency long enough to blow out all of those viruses and the patient could be cured or at least sent into significant remission. Obviously the research has to include determining if the same frequency will also liquify the patient's liver or some other sort of 'side effect'.

I've always enjoyed the kind of fanciful reality that as an audio engineer I work directly with such a fundamental force in the universe. It's kind of the spiritual and metaphysical side of the business that truly takes us beyond the subtle geekdom of gear lust and down into the deepest caverns of obsession.

-Jeremy

[jmiller]

While I was reading this, there was an earthquake. Freaky.

Nothing big, just the usual Valley jolt.

[onedyingtim]

how low of a frequency can you record and playback?

how would you even go about figuring out if it is there or not?

maybe a ridiculous question but it just seems like you could do some really amazing things with the mood altering low frequencies.

[Red Rockets Glare]

hey prof, your comments got me really curious. it's called the Schumann Resonance, and scientists believe it's rising.

[Professor]

There you go, I figured someone might do a search and find the correct name. Of course that makes me wonder why I thought it was Helmholtz - he is a famous psychologist. When I first heard about it, I thought that we must be altering it in some places. Every time we build a huge parking lot or airport, everytime we drain a swamp, and certainly every time we build a city we significantly change the density of the ground and I would assume the resonant frequency.

As for the question up there on recording and measuring the sound, it can be done. I think that as long as your recording system doesn't have a low cut filter on the electronics, it should extend down below 20Hz. Microphones like the B&K (DPA) omni mics extend down to 3Hz while the Earthworks QTC-1 mics will extend down to 4Hz. And there devices called 'frequency counters' that are pretty easy to find that do exactly what the name implies - the only trick would be finding one that is good down in that range. If you wanted to generate the tones, I'm pretty sure that most synthesizers will let you kick on a Low Freq. Oscillator (LFO) and send it to the outputs as a normal patch.

When you consider the effects of infrasound, and the fact that lots of folks with subwoofers in their systems can reproduce the frequencies, it kinda makes the full range speakers in mastering that much more important. I have seen extremely low frequency sound on my recordings through the oscilliscope I use during mixdown. In the case of one recording I had some pretty substantial LF information that my speakers weren't playing back to me, but it showed up as a scope trace in XY (phase meter) mode where the little trace was just dancing around wildly during the 'silent' part before the performance started. I didn't measure the frequency, I just put in a 25Hz roll off and got rid of it.

Of course if you really want to experiment, you need a couple of these bad boys. I have two of the Silver tactile sound transducers that I bought for my home theater before moving to WA. Unfortunately they are waiting in storage for me to buy a house. But damn they are fum to play with. Power them with a few watts, press them up against a concrete wall and the whole wall becomes a speaker. Yeah.

-Jeremy

[djimbe]

This low frequency discussion reminds me of some talk I saw on the Cool Edit site about low frequencies that cause some folks to develop a serious need to...ahh...deficate. Some wag dubbed it "brown noise"....

Hey Prefessor...those tactile sound transducers look pretty cool. Any experience using them as a driver for a plate reverb? I know I'm not the only one here looking for such a device, and the low budget model doesn't look prohibitively expensive given the cost of EMT's these days...

[Professor]

Never tried it, but of course now you have me interested. The tactile transducers are designed to move mass instead of air. Anything you bolt them to starts moving and the littlest ones put out about 1.2 lbs/watt as I recall so a 100watt amp will push 120 pounds of force. That is pretty serious and certainly more than enough to excite a reverb plate. I suppose if you cut a hole, dropped a nut and bolt on and threaded on the disc you would be in business. Great, now I want to go try it out.
You could have a collection of different size, shape and thickness plates and just bolt on the disc and setup a clean microphone to pick up the result. Infinitely adjustable and dirt cheap. The little discs have a list price of only $199 and I won't tell you what mine cost except to say that it was good working for a dealer.

What I always wanted to try was using them as a sort of speaker driver with a large wooden horn. Then they would trigger air movement and radiate it. Holding them against a wall does create audible sound and their frequency response is pretty wide. Of course since you mentioned the plate I also thought of creating two hanging steel plates like 3' wide by 6' high and bolting the discs on to vibrate them and turn them into speakers for some weird electronic music stuff. Damn, all the cool possibilities.

-Jeremy

[The Gibbon]

I thought "Helmholtz" was responsible for the "Helmholtz Resonator"....a way of trapping frequencies and cancelling them out (commonly used in real studios) using a method not unlike a coke bottle...frequency goes in.....trys to come out ....and cancells itself.....a sort of frequency suicide.

[djimbe]

O.K. Jeremy. Enough validation for me to think more seriously about building some sorta plate 'verb device with these things. Your idea about coupling them to some sorta horn reminds me of a new amp that the folks at Specimen in Chicago are building. Looks alot like an old Victrola; speaker element firing into a big horn. Was at the shop a coupla weeks ago and boy do those things look cool. Didn't ask to hear it, but I may be taking our sitar there for new strings soon, so maybe that'll be my opportunity. Cool shop, Specimen. Super nice people and great craftsmanship. Don't have the URL handy just now, but you might choose to Google "specimen". It's the first place that comes up...

[Professor]

Since the drivers top out at around 3kHz, it would be pretty fantastic for a bass amp. Of course if you want the ultimate in horn speakers, there is only one Avantgarde

-Jeremy