Polarity on JBL 075 Drivers

[planetred]

Will positive to the black move the diaphragm toward the listener? I have two JBL 075 (16 ohm) wax plugs intact. Thanks for your help.

 

[toddalin]

If original, yes.

Here you go. BTW, an 075 is a 2402 and an 077 is a 2405.

http://www.jblpro.com/pub/technote/tn_v1n12b.pdf

 

[mhardy6647]

when in doubt (as those of us who dabble in vintage Altec & JBL compression drivers sometimes if not often are) -- one of these comes in really (really) handy:

https://www.galaxyaudio.com/products/cpts

 

[planetred]

Thanks for your help!

 

[planetred]

Well, it seems my JBL 075 (16 ohm) wax plugs intact drivers are correct, i.e. Positive to Red. I used a friends hand held polarity checker with a AA cell to confirm results. Surprised by our findings, we checked out several other period and modern compression drivers for proper polarity.
Thanks again-

 

[Tom Brennan]

IME the 075 sounds best with the + terminal unconnected.

 

[toddalin]

IME the 075 sounds best with the + terminal unconnected.

They actually can sound really nice with the addition of a pair of these: