[*almost*solved]Super simple project

Hello, im working on a project where i need to hook up 2 speakers to an arduino duemilanove, but me having no knowledge on electronics, has no idea how to do it.

The project is basically making something like this http://www.instructables.com/id/Arduino-Laser-Show-with-Full-XY-Control/

but with smaller speakers, and possibly less materials.

i will be using two 2 watt speakers that i need to be able to control with the arduino. Im kind of confused on how to ground everything, because i really dont want to fry my board a day after i got it.

I am using a setup like this so far but have no idea how to put two speakers on it http://www.bit-101.com/blog/wp-content/uploads/2013/05/motorcontrol_bb.png

Arduino has 25 or so mA drive capability. 5V/8ohm = 625mA if the 5V sources has that much capability. Arduino output pins do not. 5V/25mA = 200 ohm. You can connect your 4 or 8 ohm speaker if you also add a series resistor to stay above 200 ohm total. However, that won't be very loud. If you need some volume, connect the Arduino output thru a couple of resistors, Arduino to 8K, to 2K to Gnd. Connect junction of 2K and Gnd to set of selfpowered computer speakers. 8K can go down to 4K, but the output from the amplifier might sound distorted with that much signal coming in. Search the forum for "piano tones micros" for a topic where I created a bunch of tones and played them back that way. youtube link included even.

so i would hook up 8k ohms of resistance on the arduino output then connect it to an amplifier, and place a 2k ohm resistor

something like this? http://postimg.org/image/wxz9wcgmf/

like where would I connect the second speaker so i could control it independently? remember I have little electronic knowledge =p

something like this?

Sorry nothing like that. An amplifier has an input and an output. The output connects to the speakers. The input like crossroads said.

ok since I dont understand amplifiers completely.

To control two speakers would i just need to make two of these? http://www.bit-101.com/blog/wp-content/uploads/2013/05/motorcontrol_bb.png

would i just connect the two grounds together? How would I ground it?

Nice project there Crossroads. Hey think I'll get the band back together 8)


What is that three terminal device?if it is a transistor then it needs a resistor in seriese with the base.

yes it is a npn transistor.

Would a circuit like this be able to power two speakers independently?

original site

looks kinda sketchy because there are no resistors but maybe the diodes perform the same thing possibly.

The base resistors are mentioned in the parts list but do not make it onto the diagram. Diodes do not take the place of resistors. They are included to stop the back emf from the motor. These sorts of circuit are not much good for a speaker because they only pull the cone in one direction and only produce square waves.

Ok I think im understanding this a little more.

since from my speakers im looking mainly for displacement. I could make like an h block to pretty much give me the ability to drive the speakers both inwards and outwards by reversing polarity.

something like this http://shallowsky.com/arduino/class/motors.html

Im possibly thinking of just connecting an amplifier to the circuit before the speaker, because it will be cheaper and I wouldn't have to order parts online and could buy them at radio shack.

something like this http://shallowsky.com/arduino/class/motors.html

Yes that would do.

Im possibly thinking of just connecting an amplifier to the circuit before the speaker,

That is what I would do.

ok thank you guys for the help XD

helped me soo much!

ok........... i thought i had it finished, but...... can someone check this circuit out. the speaker to the right is way louder than the speaker to the left. Any thoughts? http://postimg.org/image/93uzh4isr/

Since you have the speakers driven by different ports, I would have to suspect that the code for the two ports is different.

Stil no resistor's in the base. You have two transistors so you need two base resistors. Without resistors you will damage your arduino.