Mesa OS 4x12 Impedance Curve vs Load Boxes

[Ben Waylin]

By altering the values of the inductor/capacitor/resistor network in the resonance circuit, you can make the impedance curve match your target speaker (or cabinet).

 

[RevDrucifer]

Fryette and Fractals load boxes have the ability to adjust the curves, but I’m not sure how accurately modelled either of them are.

Cliff’s pretty fanatical about that stuff, his posts about it give me a headache by the 2nd or 3rd sentence. He’s written a lot about them and impedance curves outside of Fractal that it’s definitely an area he’s gone down the rabbit hole on and after a decade on that forum, I think the biggest thing that motivates him is not getting something as accurate as it can be. I know he’s made a SHITLOAD of graphs about this stuff, to the point it’s a running joke on TGPm I wouldn’t be surprised if they were on the money.

Something I found pretty interesting was adjusting Impedance Curves while using actual cabs, which is how I have my FM9 rig setup. I don’t know what’s going on internally, but with a few amps, especially high gain stuff and edge of breakup tones, I’ve had some great results mixing up difference Impedance Curves with actual cabs, regardless if they’re the same brand of cab or not.