JBL 4333 Build (Dad's Project)

Hello everyone!I am reaching out looking for advice to complete this project that my father started and now I'm finishing. Dad had the idea of putting together a stereo pair of 4333's using the drivers he had in his collection. Now I need to complete this but am lost on what crossover I should use. The drivers and cabinet are as follows.... Cabinet = C50SM (this was a Studio Monitor C50 cabinet and not the C50 Olympus, these can originally loaded with S8 system LE15/375/HL91/075) LF Drivers = 2235H Midrange Drivers = 2441 / 2311 horn / 2308 Lens HF Drivers = 2405 Slot tweeters Not exactly a 4333 but his homebrew version, I guess. I can install a pair of LX5 / N7000 crossovers that are here, but I am wondering if the 3131A is a better choice. He has both here to use. I would have to modify the rear of the cabinet to incorporate the 3131 as this cabinet had the LX5/N7000 originally. I think it would be convenient to have the option to go with a JBL5232 or 5234 later down the road and biamplification as well. I am looking for all input from this very knowledgeable group on this build, and if there are better options then what I have listed. I wish he was here, and I could ask what his plan was, but he passed away several years ago and I would like to complete this so we can enjoy his dream.Thank you in advance for your help

I forgot to mention, Dad also has a pair of JBL 2420’s with 2312 horns. Maybe this is better suited for this build….. thanks again for the input

I would stick with the S8 load, but bail on the stock crossovers. I would go with an 800Hz and 8KHz crossover. Personally I would work up a home brew network, but you could use a 3110 and (N8000 or 3106). I'm a little confused by your post, do you have the 375s or 2441s? If you have the 2441s, then I would go with the top part of the 4355 network... 3rd order at 10KHz.

The LX5 500Hz crossover will work, but I am not a fan of crossing over any of the smaller horns that low. Going active, especially with a quality DSP will give you much more control and flexibility, but dealing with extra amps is a pain... most of my systems over the decades have been bi, tri, or quad amped... they sound great, but are fussy.


Very cool project... keep us posted!


Widget

I 100% concur.

Barry.

I really appreciate your feedback on this project. I apologize for the confusion on the parts I have here. I was going off memory. I am sitting here now looking at the drivers and crossovers available to me now.Cabinets = C50SM (pair)HF Drivers = 2405 (pair)Midrange Drivers = 375/L91 horn(pair) or 2440/2311horn(pair) or 2441/2311horn(pair), or 2420/2312hornLF Drivers = 2235H (pair)Crossovers = 3131a's (pair) or LX5(pair) with N7000(pair)I guess looking at the parts here in house I have 4 options on the midrange drivers. I know the 375's and 2440 are the same. I am told the 2441's sound better, but I assume that's subjective. I have no idea if the 2420's with the longer horn is a better home fidelity use for this build. Looking for some feedback on this. I'm currently leaning towards the 2441/2311 comboIn regard to crossovers, if I use the 3131's the rear of the cabinet will have to be modified which is not a big deal, but I hate to modify original JBL cabinets. The LX5/N7000 are easy installs but from what you're saying, 3110/3106 are better crossovers to use due to the crossover points? I like the fact that these will also bolt in without cabinet modifications.

Regarding your 375, 2440, and 2441 drivers, presumably your dad bought these secondhand so their performance is an unknown. You should test these drivers and use the best pair. In your application the sonic difference between the three will be virtually identical if the three drivers are in perfect condition.

Regarding condition, even if the DCR reading or visual condition are perfect you will not know how good these drivers are until you actually try them out. I suggest getting some basic test system, there are systems available these days that are pretty good and cost almost nothing. If you are uncomfortable with this then when you set up the system be prepared to listen to them and swap out the three pairs of drivers to find the best pair.

As far as modifying the cabinets, it is pretty easy to create blank panels to block the rear holes and use those blank panels as an input panel for an internal or even external crossover.


Widget

Thank you so much Mr. Widget for your valued input. I will test the sets of midrange drivers I have and use what sounds best to me. I guess this hobby is truly subjective and is completely up to the end user to choose what’s “best” to them and what they hear. Spec sheets and stats are just more information to absorb. In regard to the test systems you mentioned, that sounds a lot easier then swapping out these monsters every week or so to check. I am unfamiliar with these test systems but am very interested in acquiring one. Do you have a recommendation on what to get? I feel I will get alot of use from this and plan on picking up where Dad left off. That means lots of projects and fun along the way.

As you have mentioned the 375 and 2440 are identical in performance and they drop off a cliff at 9kHz. The 2441 however has pretty good extension past 16kHz and on the 2311 is nearly flat out to 16kHz.

In my experience integrating the 2405 is a bit easier with the 2441 as it has less hard work to do compared to taking all the load at 9kHz and up.

Despite several pretty serious attempts I have never been able to love the 2420-2312. ? The 2441-2311-2308 I can be satisfied with.

Like Mr. Widget referenced, the 4355 crossover integration would be good start if your 2441’s are in satisfactory condition.

There is a really good JBL Pro shop in Wixom MI if you need a hand with your drivers. Ask for Jeff.

Barry.

Low cost measurement systems:

REW is free software that is pretty powerful. You need to buy a mic and load the software. The UMIK-1 mic is very good and is just over $100
https://www.roomeqwizard.com

Studio Six Digital is even lower cost if you want to keep it simple. With an iOS device you buy their app and you can use the internal mic.
https://www.studiosixdigital.com/aud...lysis-modules/

Both of these give you capabilities that would have cost thousands of dollars a few years ago.


Widget

Thanks again Mr. Widget for the guidance. Just downloaded the recommended software and ordered the mic. I'll report back once I get it and get some more information. I will attempt to post some before photos before I dig in as well and start to record the process once I get this going. Should be a lot of fun and hopefully a wonderful sounding system. Thank you 1audioshack, I am familiar with the Wixom JBL shop. I forgot they were there. I will remember that if I need any help there. Stay tuned for next steps and photo updates.