4 12 inch woofers tested

MrEd

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Today I am going to test four woofers in a somewhat controlled way using an open baffle box I threw together a few months ago.
Tested will be Rola field coil, Jensen P12 RJ, Magnavox, and Altec 414 16c.
20211208_125545.jpg
 

MrEd

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Currently trying to do some subjective listening, hard to do switching them out and playing Pandora from a phone and powered by a class D chip amp
 
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MrEd

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After several back and forth sessions and considering all of these were playing full range open baffle my impressions are that any of these could be used with a good horn for top end and be enjoyable.
To my surprise the Jensen had the most bass output, it is the lightest and has what seems smallest magnet, but it is alnico as all but the Rola are. It may be the best suited for open baffle or a lossy enclosure.
In this group I think the stand out is the Rola, very close to the Altec.
I expected there be more distance between the 414 the others, not so much.
That said I would think the 414 would out shine the others in a proper cabinet.
I have been looking at distortion graphs and need to do some more comparisons before drawing conclusion.
All in all a fun experiment. 😊
 
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Thermionics

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First of all, thank you for taking the time to run these tests. I'm surprised that the Jensen had such high bass output, and am also surprised that the Magnavox had such a high level of distortion. I am not familiar with the Rola, but it looks to be a very interesting speaker. Given they all look pretty decent through ~ 3kHz, they should all do really well in avoiding crossovers in the fundamental range of instruments / voices.

It's too bad you didn't have access to a 414a/414z for your comparison, as the 414c you used in your shootout is a bit of a different beast (still very good, but different). More details here.
 
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MrEd

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The distortion plot is THD.
I will post more graphs of 2nd and 3rd order.
I suspect that these have much bearing on how we perceive the sound.
Maybe @Pat McGinty Can help us here, as I am venturing into a teritorey I have no authority to speak about.
Hoping to learn from this whole endevore 🙄
 

MrEd

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Too bad you didn't have a modern driver to try out also. The closest Satori I could find is a 9.5.

I had a very similar thought yesterday and wondered about some of the currently available woofers out there
 

Opa1

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Kool experiment. I have some 12" Maggies . What size is the baffle 18x32 or so?
 

mhardy6647

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To my surprise the Jensen had the most bass output, it is the lightest and has what seems smallest magnet, but it is alneco as all but the Rola are. It may be the best suited for open baffle or a lossy enclosure.
High Qts, I would imagine = "good for open baffle", you know? :)

This is very cool, especially because these aren't the kinds of drivers that usually get assessed in an objective ;) way -- other than maybe T/S parameter measurements.
The "problem" (i.e., the wrinkle to analysis) is that the electromechanical properties of the drivers will, to some extent, (differentially) color their behavior on an OB (or, of course, in any given enclosure/alignment).
I guess (???) the fairest way to evaluate them might be to hang 'em from a tree or a stepladder somewhere outside, in free space, and do similar measurements -- or to crank up one of them "Klippel" things that does soundfield measurements and can back-calculate anechoic performance from data generated in (almost?) any environment. ;)

This isn't meant to be (overly) critical nor demotivating at all. :confused: :rolleyes: I am just sayin'. ;)
That said, as always "The perfect is the enemy of the good"; this is infinitely better than what I/we knew about these drivers, say, 24 hours ago!

Thanks!!
1639077344623.png
source: ADAM Audio T7V Monitor Measurements & Conclusion

1639077294324.png
source: Kii THREE Review (sorry!) ;)
 
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mhardy6647

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Well Mr Hardy.....
I was wishing I had woofer tester yesterday to use.
As for hanging from the trees, I'm not quite ready. 😏
It would be nice to have one of those gizmos, wouldn't it? I keep thinking about getting one...
T/S parameters can be measured manually (so to speak) via brute force -- I've even done it! :redface:


1639087261955.png

Can't blame you about not wanting to dangle yourself or your woofers from a tree in the backyard, I must say. :rolleyes:
 
High Qts, I would imagine = "good for open baffle", you know? :)

This is very cool, especially because these aren't the kinds of drivers that usually get assessed in an objective ;) way -- other than maybe T/S parameter measurements.
The "problem" (i.e., the wrinkle to analysis) is that the electromechanical properties of the drivers will, to some extent, (differentially) color their behavior on an OB (or, of course, in any given enclosure/alignment).
I guess (???) the fairest way to evaluate them might be to hang 'em from a tree or a stepladder somewhere outside, in free space, and do similar measurements -- or to crank up one of them "Klippel" things that does soundfield measurements and can back-calculate anechoic performance from data generated in (almost?) any environment. ;)

This isn't meant to be (overly) critical nor demotivating at all. :confused: :rolleyes: I am just sayin'. ;)
That said, as always "The perfect is the enemy of the good"; this is infinitely better than what I/we knew about these drivers, say, 24 hours ago!

Thanks!!
View attachment 42447
source: ADAM Audio T7V Monitor Measurements & Conclusion

View attachment 42446
source: Kii THREE Review (sorry!) ;)
Fun in your own backyard!
 
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