[Teddy KGB]

Here are the two main sources that led me to my conclusion:

http://www.lansingheritage.org/html/jbl/catalogs/1957.htm
http://jblvintagespeakers.com/1950s-jbl-c37-c-37-low-boy-speaker-d130-075-n2500

Again, it's all just speculation on my part. I appreciate the advice to address the "Lansing Heritage" forum directly. Good thinking...

You guys are the best. 'Preciate ya!

Brian

[Teddy KGB]

I have more then a few of the C series here in south county.

I have run nine of ours with no problem with original crossovers installed, but if you have concern, fall to the safe side.

Adding more fibrefill is not necessarily a good idea, as these cabinets were built without T/S parameters, and are a little small.

1.) "More than a few"? Wow--seriously?! That's something I would love to see! (Any suggestions on where I might look for the legs for the cabs? Mine didn't come with them, but I can see where they would've been attached on the bottoms...)

2.) Thanks for that. I didn't hear anything peculiar when I sampled these, but I'd never forgive myself if I damaged them. Still not sure...

3.) "A little small"? Holy cow! Hard to imagine!

Thanks again. I keep having a "Where you been all my life?" feeling about this site!



PS: Do any of your examples have the same sort of logo? None of the examples I've found online seem to have the logo top center of the cab, but rather a badge on the grill cloth. Just curious...

[daves]

The C37 will be 16" deep by 24" tall(w/o legs) by 36" long. And weigh 70 pounds. 
The paste on label is older than the metal grille labels, in most cases.

[Bob in St. Louis]

You GAS guys are making me proud. 

[KenSeger]

3.) "A little small"? Holy cow! Hard to imagine!

Well,,,,, http://hifilit.com/hifilit/Bozak/old3.jpg

I have the E-301, but it's the same size as the B-301, different drivers.
 
I'ld say 19" x 36" x 53" at 210# qualifies as 'not small'. 
Ken

[Teddy KGB]

Well,,,,, http://hifilit.com/hifilit/Bozak/old3.jpg

I have the E-301, but it's the same size as the B-301, different drivers.
 
I'ld say 19" x 36" x 53" at 210# qualifies as 'not small'. 
Ken

WOW!  That. is. EPIC!

Suffice it to say, the C37s take up a lot of real estate in the dining room of my little house. I spoke yesterday with Jeff at CompuTronics in Maryland Heights, and he assured me that the crossovers--if they're working at all--should be fine to stick with. So I'll gently continue to enjoy these for the time being. Truthfully, I just enjoy looking at 'em! Such a glamorous piece of hi-fi history!

Thanks again for the warm welcome, and all the input. You guys are a credit to your hobby/obsession!

Brian


PS: When I finally get everything all dolled up and presented as I'd like, I'll post pics of the whole system. (As it stands now, I've paired the JBLs with a piecemeal system consisting of a vintage-ish Denon PMA-501 integrated amp, TU-501 tuner, a mid-90s Onky0 CD changer, and a Dual 1245 turntable [and LOTS of Steely Dan.     ])

[KenSeger]

Since your crossovers are most likely second order 12db/octave, or higher, even if the old capacitor in the tweeter leg shorted out, your choke coil in parallel with the tweeter would act as a shunt to the low frequencies (similar to a series style crossover) and drastically reduce the bass going to both the tweeter AND the woofer.  So, if any low bass gets to the woofer, you know the cap in series with the tweeter is at least doing something, and the tweeter is protected.
This would not apply to 6db/octave crossovers at all.  If a series cap in a 6db/oct shorts out, you get full bass to the tweeter and that's usually fatal.
Ken