Any speaker cab impedance measurements?

[Merlin]

Years ago I'm sure I used to visit a site where someone had collected a bunch of impedance and frequency response measurements of various guitar cabs. I can't find it now, maybe I'm misremembering. Does anyone have any links where I can find the impedance curves of cabs? (I'm mainly interested in the whole cab, not just the driver btw)

[jjasilli]

Maybe if you're real nice to IR developers they'll tell you.  Or maybe if you get an IR device with lots of IR cab simulation you can derive the impedance curves. 

[tubeswell]

IRRC, EV had sme cab design information somewhere which I think I saved on my old iMac - I’ll see if I can fire it up.


In the meantime, a (very) quick search just now brought up some interesting discussion in a thread over at MEF from not so many years back https://music-electronics-forum.com/forum/amplification/guitar-amps/theory-design/47015-speaker-cabinet-design-interpreting-thiele-small-data-using-sofware-and-tuning?view=thread


Actually there are lots of interesting threads there - like trying to find a needle in a haystack.

[jjasilli]

It occurs to me that: for open back cabs I think the speakers will follow their open-air impedance curves which may be published by the manufacturer.


For closed-back cabs the difference in impedance curves would be more significant, probably for lower frequencies.  In practice there's probably only a few significant, widely-used, closed-back cab designs. 

[Merlin]

It occurs to me that: for open back cabs I think the speakers will follow their open-air impedance curves which may be published by the manufacturer.

For closed-back cabs the difference in impedance curves would be more significant, probably for lower frequencies.

That's exactly what I was hoping to find some plots for! I'm sure plenty of people have measured them, I just can't find any decent web pages anymore :(

[shooter]

 
21st century internet sucks!


JBL used to have a great cab design section, just looked, NOPE.
here's a bunch of old links to design tools


https://www.audioheritage.org/vbulletin/archive/index.php/t-8936.html


didn't follow any, so buyer beware

[tubeswell]

Old EV spec-sheet