Impedance plot of speaker cabinets for design of reactive load.

[Humbug]

The Marshall 4x12 loaded with GB+V30 is a 16ohm cab.

I took the liberty of spicing your cab... Maybe this is your excuse to build a 16 ohm load ;-) I'll send you the files (or just the values if you're a masochist) if you're interested. The upper rise portion is exaggerated to compensate for whatever is going on in the highs in my box and will probably need to be changed, and I'm guessing at the actual magnitude and Q of the resonant peak.

 

[Orvillain]

Hey slight bump, but anyone got one of these plots for any of the Two Notes loadboxes ??

 

[Humbug]

Hey slight bump, but anyone got one of these plots for any of the Two Notes loadboxes ??

Here is the impedance curve of my captor X 8 ohm. It's basically a hammock :)

 

[Humbug]

Ok, I'm calling it... Now to figure out what causes the SPL to deviate from the impedance curve in the highs.

Update: It was/is the box. A tonewood version of the load does not exhibit any of the dampening effect at higher frequencies. Also, rearranging the high frequency inductors to a greater distance from the box walls reduced the effect.

Also: Omitting the parallel capacitors from L1 and L2 networks does not negatively affect the response (although I did need to increase the value of the second inductor by .1mH to compensate) and may (small enough to possibly be measurement error) actually improve the HF response a smidge in box.

This surprised me so much that I forgot saving the measurement files. I'll include a screenshot off LTSpice in hopes of avoiding your disapproval.

Apologies for the excessive editing. I can't brain today.