Resistors to increase speaker impedance?

[marmoset]

This is probably a stupid question, but can I add a 4 ohm resistor in series with a 4 ohm speaker, and use it with a head which needs an 8 ohm speaker impedance? I don't actually know what speaker impedance is, but as it's measured in ohms I assumed it was the resistance of the speaker.

I ask because I use a line 6 spider combo at the moment, and I am planning to save up for a new head, and use the spider as a makeshift cab by disconnecting the speaker and connecting it to the head. I can use the cab at the practice room for band practice, and mic up the head through the spider's speaker for gigs (I hope). I'm thinking of something like the Orange Tiny Terror (which is 15 watts clean, presumably more overdriven). Would a single 12" speaker be overloaded by this?

Thanks for your help, and sorry if it's a really stupid question  :oops:

[MDV]

You could add a resistor to the circuit but you'd have to calculate its value more carefully.

Imedence is analogous to resistance, but its for AC, not DC. The DC resistance of the circuit is a factor, but its not a simple addition.

[marmoset]

Thanks, I guess I'll ask my physics teacher if I want to do it, but I need to save up for anything I do buy, so I've got plenty of time to ponder  :(

[5F6-A]

Imedence is analogous to resistance, but its for AC, not DC. The DC resistance of the circuit is a factor, but its not a simple addition.

that's right......