BillFitzmaurice.info

Is anyone else contemplating playing a 15-20 hz frequency through their subs to give the house a "haunted" feel? I am really thinking about doing exactly that through my THTs to spook the neighborhood! It should scare my neighbors since the low frequency should carry right into their houses and shake their dishes, pictures, etc. And they won't hear the sound...

Yahoo!

I remember hearing the "wierded out" feel comes from about 10hz or so. I am not sure though

Great idea. Modulate it for extra ooooooohhery weirdness.

If you had two you could beam some gnarly focussed interference patterns into specific neighbours' lounge rooms. Split subs on a mission from hell. If someone does, please share the maths!

I remember reading that the "dread" feeling is right around 19hz, think it also affects eyesight a bit causing minor illusions.

This is a really cool thread, I'm interested to see how it comes out. Monomer (?) or someone who has <4 THTs, they should rattle the whole neighborhood

Well, I have 2 THTs and a BASH 500 amp that I know for a fact can rattle my neighbors window and I don't think they can conciously hear the sound. I was actually joking that if any of my neighbors made me mad, I would leave for a weekend and leave a 15-20 hz frequency blasting the whole time I was gone so they would be freaked out and move.

Aphex Twin's "Selected Ambient Works Vol II" album contains a good amount of creepy stuff on it. There are also a few select passages from the Silent Hill 2 & 3 soundtracks that I always thought would make for great HH background.

What a great idea. We are doing sound for the Halloween street dance in town a couple of blocks from our shop. I'll fire up all the HT subs in the shop with a modulating subsonic tone all night.
Cool idea!

Ding ding, a winner.

If you do it right you can focus very intense out of phase, back in phase interference beat patterns. Need the right frequencies and separation distances.

With a staggered fixed frequency pair, minus the modulation, you would get a pure beat frequency at fixed nodes. I'm not clued up on the maths enough to give you a prescription.

Say one set is doing 20Hz to 22Hz and another set pure 19 Hz, you get a womp womp at the modulation frequency, I think, with nulls and peaks which sweep across the landscape. The mind boggles how freaky that could get. Range of a couple of city blocks might be a stretch though.

I don't know if mixing sub breeds is a good idea. You might get accidental overexcursion.

Gregory East wrote:With a staggered fixed frequency pair, minus the modulation, you would get a pure beat frequency at fixed nodes. I'm not clued up on the maths enough to give you a prescription.

These are beats of mistuned consonance.

The formula can be found here:
http://hyperphysics.phy-astr.gsu.edu/hb ... /beat.html
and a demo here:
http://hyperphysics.phy-astr.gsu.edu/hb ... ox.html#c1

Well I don't think I have any equipment with which to modulate sound, just a receiver, sub amp, bluray player, and laptop. If anyone has an mp3 or cd with the mentioned infrasonic frequencies please let me know, I would like to get my hands on it!

67baja wrote:Well I don't think I have any equipment with which to modulate sound, just a receiver, sub amp, bluray player, and laptop. If anyone has an mp3 or cd with the mentioned infrasonic frequencies please let me know, I would like to get my hands on it!

I think you could use Audacity to do it but I am a bit naive on that program still

Audacity can be used to create tones, open it up and click 'generate' then pop in the details of the tone (frequency, type, length), hit create and fairly soon you'll have something suitably evil to pump out of your subs...

67baja wrote:Well I don't think I have any equipment with which to modulate sound, just a receiver, sub amp, bluray player, and laptop. If anyone has an mp3 or cd with the mentioned infrasonic frequencies please let me know, I would like to get my hands on it!

Take another look at the formula I posted. You don't need to modulate anything. The interference of the waves accomplishes the modulation. Just two tones, each at different frequencies, and they'll "beat" at the the difference between the them. Try a 20Hz tone and an 18 Hz tone, they'll beat at 2Hz. 30 and 32 and it'll sound like the engine room of a submarine.

Tonegen is also another good freeware program for running experiments.

25 and 15?

Note that the f2-f1 beat formula assumes sources at equal distance from the listener. When you separate the sources you can factor in your delay time to get intentional combing reinforcement/cancellation.

One of the DJ guys with some T36's did it a few years ago when he had "neighbour issues". He had it all worked out to pound next door's living room with a huge infrasound node that you couldn't hear coming from anywhere in particular.