Doesnt resistance mean same as impedance??

İmpedance is resistance which changes with frequency whereas simple resistance is constant with frequency. 

I can remember that one pretty easy cakyol.

<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

pwerahera 

You have to be kidding me, a true squint's answer, I'm impressed, but still no answer for the OP. Like me talking the guy off a 40 foot telephone pole. "Jump, just try to hit the grass". Splat! Ops, wind changed by .21760943% X 21 -.33456. LOL

Regards

Just to say,

OP, (having the impediment of resistance to learning) asked about preamps and amps, you Brainiacs leapt in on Speakers.

@erik_squires I am a physicist.  My understanding is pretty darn good.  This is a simplified explanation for the layman.  You seem to be struggling to execute that. 

Better to struggle withe truth than be comforted by falsehoods.

     "Impedance is resistance which changes with frequency whereas simple resistance is constant with frequency."

     There is NO frequency with DC, which is WHY, "resistance is constant".

     With ONLY a single strand of solid wire: passing an AC current (ie: with a frequency) through, will cause that wire’s effective cross-sectional area to be reduced, via skin effect*, thus: an increase in measured Ohms (knowledge regarding electricity that has been around since the late 1800s).

                    * https://en.wikipedia.org/wiki/Skin_effect

      Even you wiki-scientists should be aware of such a basic electrical measurement!