1 watt 8ohm speaker inductance

I'm trying to come up with an approximate inductance value to use for a 1 watt 8ohm coil resistance small cone speaker, basically the kind you yank out of cheap radios. I don't have any way of measuring the inductance though, can anyone give me a ballpark figure to use?

Edit: The only refrence to a measured static inductance I've found so far is 560uH

Why would you want to know?, it's not really of much use as it doesn't act like an inductor.

Was trying for a quick and dirty way of getting a better simulation of a speaker aside from an resistor. Never mind though I found a decent spice model that simulates the physical properties of a speaker that's not too bad.

you can't just treat a speaker as an inductor.
a basic rep would be a resistor, if you are starting to want a more detailed model you have to include variable inductance and such... not worth the hassle unless a pro

A number of years ago I read a magazine article about speaker enclosures, amplifiers and other audio system components. I was left with the impression that the reactance of the speaker was related to the frequency - and the physical characteristics of the enclosure that changes the way a speaker behaves (as compared to open-air).

The whole point of the article was to explain that the enclosure/speaker pair - and amplifier can be matched or mis-matched in terms of frequency response. The reactance differences across the spectrum were not trivial. Sometimes the differences offset other characteristics - other times it compounded a problem. I distinctly recall the author explaining how applying pressure with a fingertip to the cone would significantly affect reactance as they swept the audio range. It appeared that the author did a lot of measuring and analyzing.

Not sure if this helps but thought I'd offer just in case.

Sceadwian said:

Was trying for a quick and dirty way of getting a better simulation of a speaker aside from an resistor. Never mind though I found a decent spice model that simulates the physical properties of a speaker that's not too bad.

Click to expand...

A resistor is probably as helpful as anything else?, unless you can find an exact spice model for the speaker and cabinet you're using - but an inductor would be no use at all.

Some years ago I needed to find the impedance of a cheap unknown speaker.
Cutting a long story short, the speaker was 3ohm and within my measurment accuracy was resistive from 20 to 1000hz.

JimB

JimB said:

Some years ago I needed to find the impedance of a cheap unknown speaker.
Cutting a long story short, the speaker was 3ohm and within my measurment accuracy was resistive from 20 to 1000hz.

Click to expand...

Easier to just measure it's DC resistance? - it's about 75% of the impedance, and is plenty accurate enough at that. Interesting you didn't get a peak within that range though!.

I want to feed simulated amplifier output into a simulated speaker to see what kind of results I can expect. It's just a learning exercise for understanding more complex circuits in spice than just a few basic bits glued together real fast. I'm not used to dealing with complex electromechanical systems and I'm learning on my own. After viewing the schematic I understand it a little bit more, there's a few increasing resistor values right off the bat fed into a parallel array of inductors to give a variable inductance for the voice coil. A couple parasitic capacitors that simulate the actual physical feedback from the cone mass.
I found a schematic for LTspice on the Yahoo Groups forum for ltspice
It's attached if anyone wants to see it.