Is it possible to use normal stuff found in home to make a subsonic wave device? What I mean is in a speaker type of way.
It depends on what you normally have around the house in the form of tools and parts.
One pot.
One stick.
Strike pot with stick.
QED.
:smack:
Ok, I see now that this is a trick question.
A speaker like device that produces subsonic waves. No, you do not have anything in your house to make such a device.
Speaker -> Sound. Sound travels at the speed of sound (Duh). Subsonic sound = not possible.
1 bathtub - filled approximately 1/2 way
1 board or other suitable waterproof flat object about the size of a notebook.
Splash the water back and forth in a smooth motion.
Now you have a subsonic wave.
I think he means infrasonic, as in lower than 20 Hz. At least that’s what I think he wants…
As you can see Moeman we have no shortage of people who will answer what you asked, though it may not be what you wanted to know. You may want to be a bit more specific on what you want.
FWIW I suggest thumping the cone of a woofer cone. Much more speaker-like than pot-like 
Argh, I should have been more specific. If you thump on your speaker and can hear it then the transient isn’t infrasonic. Pushing it repeatedly might be better.
I wouldn’t encourage him. He might be trying to make device that produces just the right frequency and volume to create “the brown note.”:eek:
Bag End’s ELF speakers are supposed to go flat to 8hz, but you aren’t going to build one of those yourself. There is a circuit called a Linkwitz something or other that will Eq a sub down pretty low. If you are looking for true deep bass you are going to need big drivers, big amps (or big horns) and a big enclosure.
Is this what you are asking about?
Which isn’t true. I’m too lazy to find a cite, but if you search the SDMB, you’ll find several threads on the topic.
Yes that is what I am loking for sorry I don’t know all the technical terms:smack:
Ok, stupid question time. What is a brown note???:eek: :smack:
What exactly is your application, moeman? It might help if I knew what you had in mind.
I suppose you need a sub-woofer.
The South Park episode “Worldwide Recorder Concert” featured a concept called “the brown noise,” a particular frequency of sound that would cause anybody hearing it to lose control of their bowels and … uh … “have an accident.” The note that did this was described as being “ninety-two cents below the lowest octave of E-flat.” Obviously a joke, but there are real rumors about the existence of certain low-frequency sounds that cause anxiety, panic, loss of consciousness, crapping your pants, etc. I think there are already several threads discussing this somewhere on the message boards…
My neighbors kid does not think there is any noise that people don’t hear. I was trying to build a small project to show him there is noise you cannot hear. I thought that I could use a piece of paper in front of the object to show that the there was something there he could not hear. But now reading what I just wrote I am not sure that would convience him either. Oh well just a goofy idea.:smack: 
Oh, that’s easy, just go the other direction: Dog whistle.
And build an Ultrasound detector to listen to it.
That’s what a dog is.