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ngccglp
05-28-2004, 03:19 AM
With the insistence of my friend who used to own JBL studio monitors, I connected a 1.5V battery across the terminal of the speakers (+ to red terminal, - to black terminal). To my surprise, he was right, the woofer sucked in instead of pushing out.

May I know which is the correct way? Should I now connect the + of the amp to the black terminal and vice versa for the - ? I've checked the internal connection and it is according to the JBL pdf for 4333B, i.e. black to black and all other colours wire to the red terminal of the drivers. I don't think it is different for 4333A.

Thanks.
David








:confused: :confused:

4313B
05-28-2004, 03:49 AM
We've been over this before... JBL's suck, all other brands blow. Learn it, live it, love it.




Note - JBL has finally succumbed to the "rest" of the industry and therefore all their newer transducers also blow.

ngccglp
05-28-2004, 04:21 AM
Giskard, Thanks.:)

Any science behind this 'suck' phenomenon?

boputnam
05-28-2004, 06:59 AM
Originally posted by Giskard
We've been over this before... :banghead:

Hey, David...

There are (too) numerous (to mention...) Threads discussing this, ad nausium. While it can be confusing, it needent be, and can (as you've seen with the battery test)... amaze your friends. Try the Search button for "Polarity", and sit back with a case of red wine for the some reading.

ngccglp
05-28-2004, 03:17 PM
It was indeed an interesting(confusing) read. I've been thinking about this the whole night, still couldn't understand the logic. If the source and amp is pushing (+), how can the woofer be sucking? That would mean the speakers are out of phase with the source+amp. Shouldn't it be pushing as well regardless of whatever JBL convention?:confused:

David

boputnam
05-29-2004, 11:03 AM
Originally posted by ngccglp
If the source and amp is pushing (+), how can the woofer be sucking? That would mean the speakers are out of phase with the source+amp. JBL did this to confuse the electrons - after building them passive network themeparks the little buggers wanted everything. These reversals kept them from becoming photons - GE was really against lighting-up your room with mere speakers... ;)

The point you raise has bearing more in live instances, where say the drum purcussion wave might be out of phase with the woofer (for an instant), but with the distances involved and non-echoic conditions, it is unlikely even then it would really matter. The attached excerpt from Ashly's XR crossover manual notes JBL's uniqueness, and gives sound ;) advice.

It is imperative that all transducers covering like-frequency ranges be in-phase, to avoid unintended cancellations.

johnaec
05-29-2004, 11:34 AM
And don't forget the amps and other components when working with balanced input equipment. Industry standard is pin 2 hot, yet there's tons of equipment with pin 3 hot, (180 degrees out of phase).

I've got four Crest amps, and two of them are pin 2 hot and two are pin 3 hot, from the factory!! And even though pin 2 hot is virtually standard, my old sound company, (Ultra Sound - now Pro Media), wires everything pin 3 hot...I was just talking with them about this the other day...

John

Mr. Widget
05-31-2004, 10:17 PM
...and let's not forget some amps invert phase so even unbalanced amps can get confusing.


Widget