I understand the magnetic principle behind the working of speakers and microphones. I am just inquiring into the circuitry sense of it. I am pre-designing a project where I would require a very basic speaker where I could modify the frequency at which it plays. Old speakers from headphones or computer speakers would probably be the primary source, with a homemade resonance chamber for my purposes. In order to modify the frequency though using a "basic" circuit, I was wondering about the configuration of this. Would it be accomplished with a variable resistor, an oscillator or timer, and a speaker, on the most basic level? (With batteries, resistors, switches and LEDs to taste of course)

 

EDIT: Change in oscillator requirements

Edited April 30, 201411 yr by HRS

A variable resistor can modify the frequency over a certain range, and you can use a different capacitor to get a different resistor modifiable range.

 

This page gives a simple circuit and parts list: >> http://www.electrokits.com/Sound-Effects/Transistor-Organ

Thank you very much that should be very helpful. Although the circuit you posted is a little different than what I wish. It had several different tunes. Though I do find it very helpful.

 

But judging by that circuit, could I substitute R1-8 for a Resistor Substitution Box and be able to play a very large variation of frequencies? I'm not looking quite for something along the lines of a musical instrument, which this circuit emulates.

Edited May 1, 201411 yr by HRS

Thank you very much that should be very helpful. Although the circuit you posted is a little different than what I wish. It had several different tunes. Though I do find it very helpful.

 

But judging by that circuit, could I substitute R1-8 for a Resistor Substitution Box and be able to play a very large variation of frequencies? I'm not looking quite for something along the lines of a musical instrument, which this circuit emulates.

Glad it was helpful. Yes I think you could use the resistor substitution box, keeping in mind the pots listed for R1-8 are 250K. Once you get an audible tone you can experiment with different values from there.

Thank you very much