RadioShack 8ohm speaker circuit

thatoneguy

Joined Feb 19, 2009
6,359
Ok. I give up. Here we are trying to help you and all you can respond with is I'm just experimenting.
It's good to have an idea of the limitations prior to an experiment when tinkering. Buying new microcontrollers or speakers would get old after a while if doing it the "Irish Way".
 

#12

Joined Nov 30, 2010
18,224
That project is about using a piezo element as an input, not how to use an 8 ohm speaker as an output.

At this site, this is called, "pulling teeth" because it's like pulling teeth to get you to say what you really want to do. It makes us run out of patience.
 
So I got one of these cheap Radio shack speakers and im interfacing it to a ADC on a microcontroller. The speaker is rated for .2 watts max. How do I hook this thing up without frying it? Someone mentioned hooking it up in series with a current limiting resistor would work. Is this true?
.2 watts?

I own a recording studio and am very good at understanding Speaker..."REALITIES"...which tend to be very different from what the manufacturer states are the speakers specs.

I will try to help. Tell me what the specs are as far as frequency...the size of this thing and what you are using it for.

Split Infinity
 

Thread Starter

kingArgon

Joined Mar 20, 2011
33
frequency: 300-800hz
rated input: .10W
max input: .20W
impedance: 8 ohms

im connecting a speaker to a adc of a microcontroller and using it as a microphone instead. I also want to use it for PWM output using a signal generated by the microcontroller. I dont want to burn up the speaker though. What is the right resistor to use with the speaker to protect it from too much current. I calculated a 200ohm resistor in series with the 8ohm speaker should be okay. Am i wrong?
 

thatoneguy

Joined Feb 19, 2009
6,359
That project is about using a piezo element as an input, not how to use an 8 ohm speaker as an output.

At this site, this is called, "pulling teeth" because it's like pulling teeth to get you to say what you really want to do. It makes us run out of patience.
Ok, yeah, I'm confused. I guess if I read every other reply or something, it made sense for a bit.
 

thatoneguy

Joined Feb 19, 2009
6,359
Just to clarify..

You want a knock sensor using a piezo element on an ADC port?

You want an 8 ohm speaker output on a digital output?


ETA: You want a speaker for both purposes? That is possible, but a bit more intricate than separate sensors.
 
OK...I just noticed the link you provided. A speaker this small is going to be very susceptable to distortion and possibly frying due to to great an input signal as well as easily blowing due to any frequency between 0-800 cycles getting to it either unregulatated or removed by either passive or electronic crossover. A Compressor/Limitor either passive or electronic is a MUST.

If you are running two at 4 ohms these problems are multiplied. Radio Shack speakers...at least 8 inch and up...are not that bad but I would not begin to compare them with JBL Pro SRX series. The Radio Shack Micro Speakers also are not that bad as I have listened to them in use as headphone speakers.
The power needs for this thing are small but unless you are using an amp specific for use with such speaker size and design as such amps tend to be part of an overall system of amplification, frequency selection, Compressor/Limitor...etc...you are going to have to be careful not to blow them.
Split Infinity
 
Top