Variable frequency speaker driver

Hi again folks.

I am a bit of a photography person and was seeing some "tricks" with sound and water at a site.

A small flow of water was falling in front of a speaker and it was oscillating at about 34 Hz.

This made the water do some weird things.

If the frequency was adjusted a small amount it looked like the water was falling up - rather than down.

Yes, this was a video, but the shapes the water was made into was quite nice.

So I was thinking: Can I make a circuit to oscillate from ...... 5 to about 100 Hz?

I understand I will probably need an AMP as well. Dunno if the normal off the shelf music one would cut the mustard, but that's something else.

Anyone?

What circuits? Arduino or w/o? You need powerful sub-woofer, I've seen a video.

Magican,

Well, as there would need to be a "driver" to control the frequency, I was thinking of using an Arduino to do that.

Then the output is sent into an AMP to make the "sound".

Link for video: http://www.youtube.com/user/brusspup#g/u

One of those links. There is a montage of stuff and while watching it I saw the "trick" with the water and sound. As it was a montage and I wasn't really looking for it in particular I didn't get the exact link.

If there would be arduino, have you seen a "Tone" function? http://arduino.cc/en/Reference/Tone Regarding possibility for trick in a video, when water looks running up, I don't think so. Most likely, simple stroboscope effect. Low frequency only helps to split a continuous stream of water into separate drops, and beating two frequencies - camera and subwoofer create illusion. Same, as occasionally spoke on the wheel rotating in opposite direction.

Yeah, I realised it wasn't really running up hill.

It is to do with strobeing

But what I am wanting to do is make the oscillator which drives the speakers to see that happening my my own eyes.

You even don't have to build a circuit for 24 Hz, there is a lot free software signal generator you can download and run on your computer. But you still would need a powerful speaker system.

Oh, ok.

Thanks.