Uses for a 5 Hz frequency?

[Dr.EM]

Producing 5Hz as an "audio" tone from any conventional speaker is a nearly impossible task; if you wanted any "useable" output level. Any reflex design (like most 18" PA bass bins and subwoofers) will unload below 40Hz or so, output level falls off rapidly below this point (~24db/octave), by 5Hz the cones are just "flapping in the wind"

A specially designed system may produce some output at such low frequencies, but as a minimum it will be enourmous!

 

[malfunkshun]

In-car nag responder, 5/second should be enough to answer 'are we there yet?'

 

[MikeHunt79]

5Hz would be useful for earthquake detection equipment calibration and avalanche control, if you're talking about 5Hz sound waves...

You can't actually hear 5Hz however, but you can certainly feel it.

Dr EM: Some dude in the US built a massive long horn, around 70ft I think, good for 8Hz!

 

[Tomsk]

I'm surprised you didn't think of this.

A 5hz weapons trigger.

 

[bloodiedathame]

Edited for safety.

 

[vertica]

IIRC the human body exhibits resonance at about 5Hz, so a vibrator may be the best use

 

[Efour]

5hz non lethal death ray

 

[Biohazard]

5hz non lethal death ray

Up the bum!

Side note; not seen you for a while.

 

[chuck990]

strobe on its own will be fine now no death rays (non lethal my ass ) or brown noise required!

 

[Feek]

strobe on its own will be fine now no death rays (non leth

There's no such thing as ..........

 

[Tefal]

iirc very low frequency radio waves are used to communicate with nuclear submarines, because they are very hard to either intercept or detect or something.


but they require the sub to tow a huge cable antenna and the sending station requires kilometres of cables.

 

[Jonny69]

Producing 5Hz as an "audio" tone from any conventional speaker is a nearly impossible task; if you wanted any "useable" output level. Any reflex design (like most 18" PA bass bins and subwoofers) will unload below 40Hz or so, output level falls off rapidly below this point (~24db/octave), by 5Hz the cones are just "flapping in the wind"

A specially designed system may produce some output at such low frequencies, but as a minimum it will be enourmous!

Yes but have you ever stood in front of a big driver running low frequencies at high power? Sure you can't hear it, but it blurs your vision and you can't think because you whole body is vibrating slowly

 

[Tefal]

http://en.wikipedia.org/wiki/Extremely_low_frequency

http://en.wikipedia.org/wiki/Very_low_frequency


tbfh will blow the socks of "makes your vision funny"


Build one, nuke china

 

[jak731]

Infrasound can have some weird effects.

http://en.wikipedia.org/wiki/Infrasound#Human_reactions_to_infrasound

 

[meghatronic]

If you're talking about Brownian noise then I agree, but that's the correct name, not brown noise. I've never heard Brownian noise called brown noise

Oh, and I'm not a youth

Brown noise is fine. As named after Robert Brown.

Page 121 of Rhythms of the Brain.

Things can have more than one name you know...!

 

[Dr.EM]

Yes but have you ever stood in front of a big driver running low frequencies at high power? Sure you can't hear it, but it blurs your vision and you can't think because you whole body is vibrating slowly

I haven't stood in front of any PA setup running anything like 5Hz no, typically they filter anything below about 40Hz very sharply to avoid overexcursion. I can only go by theory which says that a system tuned for a passband of about 40-100Hz will have such low efficiency at 5Hz that acoustical output (any output other than heat) will be negligible. A vented alignment tuned around 50-60Hz as they might be will allow the driver to completely unload at 5Hz, meaning excursion runs out with just a few 10s of watts, even on an 18"! You'd need a special system designed for infrasonics to produce output at these frequencies, like the 'matterhorn'.

None of this is to say that around 40-60Hz these setups don't produce a very visceral bass sensation! That's exactly what they are good at/designed for, and you'll certainly get bass in your chest and trousers flapping at these frequencies

 

[J.B]

Myabe I'm just not creative enough but you could use it as a counter or timer. So it incriments every 5 wave forms.

 

[Bear]

iirc very low frequency radio waves are used to communicate with nuclear submarines, because they are very hard to either intercept or detect or something.


but they require the sub to tow a huge cable antenna and the sending station requires kilometres of cables.

The reason subs use very low frequency radio waves is because they will be transmitting through sea water which is a very lossy medium for RF. The lossier the medium means that the higher the frequency the signal is being transmitted the higher the attenuation of the signal over distance.

If you transmit a signal of around 2MHz in sea water, the attenuation would be about 50dB per meter, so you can see that it would be totally ridiculous to transmit at anything but at low frequency.

Subs use really long cables for antennas because for an antenna to work optimally (resonate) its length should be 1/4 of a wavelength. So say using a 300kHz radio system, the antenna would be 250 meters long to work in air, for a radio system working at 100kHz the antenna would be 750 meters long. Working in water modifies this somewhat but it does illustrate why long antennas are needed.