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Max SPL
06-04-2007, 11:48 AM
I just joined this site last night, and I think I'll be spending a lot of my free (non listening) time here reading.

I have a pair of JBL 4311As, and I just purchased a pair of 4311Bs from eBay. I haven't been able to find much literature on the Bs. I plan to run both pairs together with my Crown CE 1000. Does anyone know if there is a difference in sensitivity between the two? Are the crossover frequencies close enough that I won't have any phasing problems? Both pairs will be placed horizontally, one atop the other. I'm also considering another CE 1000, so I can run them both bridged.

I absolutely LOVE the 4311s. I was a live sound engineer for over 20 years, and I rarely used (or liked) anything other than JBLs. One band did have a pair of Gauss 15s that would handle anything. They were loaded into folded horn cabs. They could handle all the power from a Crown PSA-2 I could give them.

I'm also using a dbx 231 EQ and Aphex 204. A Lexicon MPX 110 gives TV programs a little space. My preamp is a Behringer mixing board, which I want to replace with a Soundcraft (preferably a 200B). I balanced the outputs of the TV with DIs, and the whole system is low impedance.

And, yes, I like it loud. Thanks in advance for your replies !

Robh3606
06-04-2007, 12:14 PM
Hello and welcome to the site. They should be similar enough so you can do what you want with them. Watch the impedence running pairs it can drop quite low. The differences will mostly be changes from alnico to ferrite conversion.

Rob:)

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/4311B%20ts.pdf

4313B
06-04-2007, 02:59 PM
Expanding on Rob's original post:

Component complement of 4311A and 4311B:

http://www.jblproservice.com/pdf/Systems%20Reference%20Charts/Studio%20Monitor%20Series.pdf

Note the listed network models, 3112A and 3112B.

Looking further on the JBL Pro website - network schematics of the two systems:

http://www.jblproservice.com/pdf/Network%20Schematics/3112A&B%20Networks.pdf

Mike Caldwell
06-04-2007, 05:38 PM
Hello
If your into a little experimenting and if the cabinets will let you do it with no major modifications. Since you plan on stacking the horizontal on top of each of other it may be interesting to swap the placement of the mid range and the tweeter in pair of cabinets so they would stack either with the tweeter next to each other or the mids next to each other. The coupling one way or the other may help with the overall image.

I have never heard it done but if the baffle cut outs would allow it would be a interesting experiment.

Mike Caldwell

pelly3s
06-04-2007, 08:21 PM
if you are gonna spend the money on another ce-1000 i would suggest selling the amp you have and putting the cash into a good used k2. I second what Mike has said about playing with driver placement with the tweeters and mids it could be interesting to find the results.

Max SPL
06-05-2007, 09:31 AM
Thanks for your replies, Robh, Giskard, Mike, and pelly !

Robh - Crown power amps have always been reliable for me at 4 ohms. The only time a Crown ever clipped (DC 300A) was when it was running at 8 ohms. I've also pushed their PSA-2 to full output at 2 ohms with no problems. Love that Crown power !

Giskard - thanks for the links. It seems they use the same network. If I run into problems, I can always tri-amp them.

Mike - It would require a lot of work to swap the mids & tweets. Not only the size of the cutouts in the baffle, but the enclosure for the mid driver. I don't posess the tools (or the skills) to do the necessary surgery. Much safer for me to leave them as-is, rather than ruining them (which I know would happen). It would be a good idea to try for someone who is capable of doing it, though.

pelly - I just checked out the K2's manual. Huge power outout, damping factor of over 3,000 (!), and no fan noise (no fan). The CE 1000 has been fine for my purposes, but the fan sound can be annoying (especially during an acoustic passage). Just noticed you're from Springfield. Played a lot of clubs there in the '80s. The bands were Justin, TKO, Lodestar, Desire, and a few others I've forgotten.

Thanks again for your replies and time.