Mixing speaker wattages in one 4x12

  • Thread starter Thread starter Greg_L
  • Start date Start date
nice !

I've always loved the way those things look.

They sound okay too! :D

Now for my next trick, I'm on to re-shielding my Strat. My last attempt didn't work worth a fuck, so I got some better shit (copper foil) and I'm gonna take better care to do it right.

Just cutting the copper I've sliced my hands about 6 times already. Fun times.

20121114_094640.jpg
 
Impedance figures are nominal and the actual impedance of any driver varies with frequency. If there happens to be a frequency at which one driver has a substantially lower impedance than the other drivers then it will draw significantly more than its share of power (1/4 for 4 drivers) at that frequency.

Normally that wouldn't be a big deal as you wouldn't be playing one frequency for an extended time at high volume, but if you're into channeling Jimi with high volume feedback it might be an issue.

800px-Znom3.png
That impedance curve looks to be for a 4 Ohm driver and it is a bit weird even then. The bass resonance is usually 5 or 6 times the nominal Z. But I wouldn't worry about Z curves, the impedance for a simple speaker system cannot go below the DC resistance which is about 12Ohms for 16R nominal drivers. "Hi fi" speakers with crossover caps in them can get very low.

Then for most of the frequency range the output Z of most valve gitamps is going to be higher than the speaker Z! It is this lack of damping that gives rock speakers the abilty to "sing"! (it is also the reason why valves ARE louder than transistors but THAT is another story!).

Dave.
 
That impedance curve looks to be for a 4 Ohm driver and it is a bit weird even then. The bass resonance is usually 5 or 6 times the nominal Z.

It's the image from the Wikipedia page on speaker impedance, posted to demonstrate the general idea. I would imagine it's a 4Ω driver since the Znom is 3.99Ω.
 
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