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classicform
01-26-2014, 04:34 AM
I've had these Minigons for a few months now and have been running them with a pair of Mcintosh MC30's. Had a small amp issue and decided to check the speakers to make sure I was using the correct tap on the 30's.


Not sure what to make of my findings:


Both speakers show the woofers with 5.2 ohms and the tweeters with 7.2 ohms.
When connected to the LX-3 X-overs I am getting a reading of 4.9 at the terminals.


All four speakers say 16 ohms on the ID plate.


Looks like they have been reconed/rebuilt at some point by "Orange County Speakers" due to their tag on the woofer.


Is it possible that these were completely gutted and rebuilt using guts that are 8 ohm and now they aren't 16ohm speakers anymore? Is that even possible?


Very confused (and a little pissed that the speakers have been dicked with so much) although from what I understand they didn't sound all that great to begin with when new so maybe this helped

BMWCCA
01-26-2014, 06:51 AM
From what I know from experience and from what I learned here, I don't believe any 16-ohm-labeled JBLs will actually measure 16-ohms in actual resistance across the coil. If your old amp has "taps" for 8 and 16 I imagine either would work fine. I haven't owned such an amp in forty years so don't take my word for it. :dont-know:

rdgrimes
01-26-2014, 11:22 AM
Sounds like you are measuring DCR across the terminals, which is different from the load they will be rated for (load on the amp). I'd continue to treat them as 16u speakers.

Mr. Widget
01-26-2014, 03:33 PM
Sounds like you are measuring DCR across the terminals, which is different from the load they will be rated for (load on the amp). I'd continue to treat them as 16u speakers.:yes:

Feel free to try other taps to see if it sounds better... but 16 ohm is likely the right tap.


Widget

classicform
01-26-2014, 04:30 PM
Thanks for the insight...I'll try the 16 taps, they're on the 8 right now and sound just so so. I mistakingly assumed that wiring two 16 ohm speakers in one cabinet would either get me 8 or 32...the X-over must factor in as well huh?

Mr. Widget
01-26-2014, 07:20 PM
Thanks for the insight...I'll try the 16 taps, they're on the 8 right now and sound just so so. I mistakingly assumed that wiring two 16 ohm speakers in one cabinet would either get me 8 or 32...the X-over must factor in as well huh?The speaker's impedance is one of the most confusing specs for most people to get their heads around. There really is no single number as impedance changes with frequency... typically the rated number is the impedance minimum.

In any event, for a system with two woofers the impedance would be half if they are wired in parallel and doubled if they are wired in series... as soon as you toss in a network, that simplicity goes out the window.



Widget