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test of speaker....

Ahh, in retrospect, I think i can see why some people get confused....Some people think amps PUSH power out, like somebody pushing a boulder up a hill...the heavier a boulder, the harder one has to push, right??

But this is incorrect. Amps don't "push"--they merely provide a voltage potential...it's easier to envision that the load PULLS. The lower the resistance, the more the load "pulls".

In reality the load isn't actually "sucking". The amp is a voltage potential and electrons are seeking to flow from the low side of the potential to the high side (if you must ask, centuries ago they arbitrarily chose "positive" and "negative" before they knew about electrons.) If there's a lot of resistance--a speaker with lots of ohms--few electrons can flow. Hence, little current flows. If there's little resistance, lots of electrons flow, hence lots of current. If the amp cannot supply the amount of current that should be flowing, the amp "clips" and bad things can happen.
 
RayW said:
I guess I'm still not seeing your reasoning. As impedance goes up the number (ohms) goes up. As impedance in a constant voltage circuit goes up, current goes down. Go back to the hose analogy. If you increase the resistance, squeeze the hose tigher, then less water flows, i.e. less current. Where is the numerical disconnect? I'm really trying to understand where you're coming from, not trying to be a jerk.

Ray
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Well maybe I'm not thinking correctly. Is 16 ohms more or less resistance than 8 ohms? Is the number 16 more or less than the number 8?
 
BillR mastering said:
Me, pulling the rope back and forth IS the weight. AC does move in both directions.
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Again, sorry but your original analogy was incorrect. 16 ohms is MORE resistance, not less, than 8 ohms. If it were a car brake system , the braking effect on the rotor is more for 16 than 8.

Your analogy falls flat because the amp is not an engine, or somebody pulling a rope, it's merely a constant voltage source. (AC or DC is irrelevant, for a pure resistive load, AC merely reverses the sign of the voltage potential at some frequency.)
 
Speakers are motors and are not pure resistive loads. But, I degress, impedance of an AC circuit compared with pure DC resistance is something that should be looked at in more detail.
 
BillR mastering said:
Speakers are motors and are not pure resistive loads. But, I degress, impedance of an AC circuit compared with pure DC resistance is something that should be looked at in more detail.
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Yep, quite true. Actual impedances vary according to frequency for an AC signal. In general terms, though, (for any given frequency) a nominal 16 ohm speaker will still (most likely) be characterized by a higher impedance than a nominal 8 ohm speaker.
 
MaxSeven said:
Well maybe I'm not thinking correctly. Is 16 ohms more or less resistance than 8 ohms? Is the number 16 more or less than the number 8?
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Like Bill said, 16 ohms is more resistance than 8 ohms and 16 is more than 8 numerically speaking. Where's the discrepancy?

Ray
 
Do you have a multimeter that reads current? Then get a battery (AA, AAA, C or D cell) and a couple of 8 ohm speakers. Hook the multimeter in series with the battery and the speaker. So the connection would go battery +, to one wire of the speaker, then the other wire of the speaker goes to the input of the meter, then the other wire from the meter goes to the battery -. For a 8 ohm nominal speaker (which has a DC resistance of about 6 ohms), you'll get a current flow of ...let's see. V=IR..., or V divided by R equals I...1.5 divided by about 6...equals about 0.250 amps. That's 250 milliamps.

Now put the other speaker in series with the first one. This is now a 16 ohm total (nominal) impedance. Actual DC resistance will be around 12 ohms. So the connection will be: battery + connects to one of the speaker wires on the first speaker, then the other speaker wire coming out of the first speaker will connect to one of the speaker wires on the second speaker. The other wire coming out of the second speaker will connect to the input of the meter, then the other wire from the meter connects to the battery -.

The current will be somewhere in the order of 125 milliamps. Voila, Ohm's law is validated. A 16 ohm speaker, for a constant voltage source, draws half the current of a 8 ohm speaker.

Extra credit: connect the two speakers in parallel--yielding a 4 ohm nominal load (actual DC resistance will be around 3 ohms)....now what will the current be?
 
RayW said:
Like Bill said, 16 ohms is more resistance than 8 ohms and 16 is more than 8 numerically speaking. Where's the discrepancy?

Ray
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Then I indeed stand corrected. Where I was thinking a higher number meant less resistance, because it required a lesser amplifier to drive.
 
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