ZMF Caldera Closed Review

X axis is frequency, Y axes are dB SPL (on the left) & Ohms impedance (on the right).

The tan curve is impedance vs frequency of the Caldera Closed (from @purr1n 's measurement); the other curves are the SPL vs frequency changes, relative to 90 dB SPL from a nominal zero-impedance amp, that are predicted from voltage division out of amplifiers with the specified output Zs.

My simple voltage-division calculator is based entirely on resistances. I do now wonder though whether any capacitor in the filter needs to be further accounted for (ie beyond its implicit effect on the impedance/frequency curve). @zach915m , I'd be happy to be corrected here if necessary.

 

For the impedance plot, gotcha (sorry I’m looking on my phone, in the sun and I am “color impaired” ).

This electrical dampener is actually a bummer for current mode amplifiers like the Bakoon/Enleum HPA-2x . You’d lose 6dB by 10kHz and 8dB by 15kHz :/

 

Didn't realize how many headphones Zach has now until your trying to discern 8 different colored lines in a chart. Converted to a table for those with trouble seeing the color changes.

 

Ok, I admit this is silly; and am weak too willed to avoid this

AO = 41.5
AC = 40.5
Auteur Classic = 39.5
Bokeh = 35.5
CO = 39.5
CC = 41
VO = 43
VC = 43