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Need some help with JBL SF15 Comp Drivers

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  • Need some help with JBL SF15 Comp Drivers

    My local watering hole has tasked me with fixing the horns on a pair of JBL SF15's. I've pulled the 2412H-1 drivers and both diaphragms are toast. Well, one's burnt the other one looks ok but reads open on the meter. I have a few questions. I see that aftermarket diaphragms are readily available, but I'm not sure of the quality of the different ones out there.

    Is there a best aftermarket replacement diaphragm among them?

    Should I check the lamps in the x-over? Will the horn work unprotected if a lamp blows or does it kill the signal to the horn?

    Is there a better compression driver, reasonably priced, for these speakers?

    Any advice on the technical aspects of diaphragm replacement, cleaning the gap, ferrofluid concerns, etc?

    Is there anything besides the x-over's lamps that I could add to protect the horns?

    Also, I can't find any info on the power rating of this specific driver, just the speaker in total which seems adequate, does any know this drivers rating?

    Thanks for any help. I'm an amateur diy speaker guy, but not well versed in pro audio. So I really appreciate and look forward to you're opinions and help.
    Buyout MTMWW

  • #2
    Re: Need some help with JBL SF15 Comp Drivers

    I've seen some bad reviews of that driver, but in all fairness - don't know the circumstances at time of death.
    http://forum.speakerplans.com/replac...opic75022.html

    One opinion is that because JBL is reputed to use a special ferrofluid, AND does not offer or recommend a replacement diaphragm - that a replacement of the entire assembly is recommended.

    * 60 watts rms
    "Not a Speaker Designer - Not even on the Internet"
    “Pride is your greatest enemy, humility is your greatest friend.”
    "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

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    • #3
      Re: Need some help with JBL SF15 Comp Drivers

      Thanks for the link

      Yes it's the 2412H-1

      It appears the diaphragms have been replaced before. Also, there appears to be some evidence that they originally had ferrofluid in them b/c when I slide a paper into the gap it does get moist from the side of the gap but looking into the gap there is no standing fluid in there that I can see. Should I replace the ferrofluid?
      Buyout MTMWW

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      • #4
        Re: Need some help with JBL SF15 Comp Drivers

        Note: I changed my response.
        I do wonder if prior attempts had addressed the Ferrofluid issue correctly.
        "Not a Speaker Designer - Not even on the Internet"
        “Pride is your greatest enemy, humility is your greatest friend.”
        "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

        Comment


        • #5
          Re: Need some help with JBL SF15 Comp Drivers

          There are 10 formulations of Ferrofluid:
          https://ferrofluid.ferrotec.com/prod...rofluid/audio/
          "Not a Speaker Designer - Not even on the Internet"
          “Pride is your greatest enemy, humility is your greatest friend.”
          "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

          Comment


          • #6
            Re: Need some help with JBL SF15 Comp Drivers

            Sheesh, how's one to know what was used... sigh, does it really matter? I guess according to ferro-tec it does. Maybe I could give them a call and they'll know what fluid should be in them.

            I seriously doubt anyone who replaced the diaphragms on these in the past did anything but remove more fluid by cleaning them and dropped in the replacements. I'm tempted to clean them out, replace the fluid with what PE sells and drop in new diaphrams b/c it's the cheapest thing to do. Then maybe if they don't hold up, replace the drivers and modify the x-over/lpad circuit if need be.

            Looks like alot of people recommend the Selenium D220Ti as a replacement, but I'm having a hard time finding sensitivity info on the 2412H, let alone a graph. I've seen 109db or so in the threads, but not sure where they came up with that figure.
            Buyout MTMWW

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            • #7
              Re: Need some help with JBL SF15 Comp Drivers

              Perhaps the manufacturer would address a specific question on that:
              https://ferrofluid.ferrotec.com/prod...io/retrofitKit
              JBL uses the 2412H in numerous designs, so that would lead me to opine that most damage of this driver is over-driving, though brief accidents can do it.
              This is a driver used on JBL lower priced models.
              "Not a Speaker Designer - Not even on the Internet"
              “Pride is your greatest enemy, humility is your greatest friend.”
              "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

              Comment


              • #8
                Re: Need some help with JBL SF15 Comp Drivers

                This is a little discouraging from their website, "To learn more, please contact your distributor"

                If the 109db figure is true which I think it probably is, the PRV Audio D280Ti-S may be a good candidate @ 110db and cheaper than the Selenium and has a higher RMS rating.
                Buyout MTMWW

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                • #9
                  Re: Need some help with JBL SF15 Comp Drivers

                  I'd e-mail them...
                  This might help:
                  http://www.jblproservice.com/pdf/Sou...actor/SF15.pdf
                  A 1" thread driver capable of a 1.6Khz crossover
                  "Not a Speaker Designer - Not even on the Internet"
                  “Pride is your greatest enemy, humility is your greatest friend.”
                  "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

                  Comment


                  • #10
                    Re: Need some help with JBL SF15 Comp Drivers

                    The 2412 is complete junk don't waste your time even buying aftermarket diaphrams for it. The Selenium DH200 will will fix the chronic blown driver problems all these budget JBL boxes(EON, JRX, SF) suffer from but if you can spend a little more the D210/220ti will also produce a healthy SQ upgrade on top of being much more durable.
                    Paul O

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                    • #11
                      Re: Need some help with JBL SF15 Comp Drivers

                      Originally posted by Paul O View Post
                      The 2412 is complete junk don't waste your time even buying aftermarket diaphrams for it.
                      +1. Its shortcomings are legendary. There's a reason why there are so many aftermarket diaphragms available for it, that being that so many of them blow.
                      www.billfitzmaurice.com
                      www.billfitzmaurice.info/forum

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                      • #12
                        Re: Need some help with JBL SF15 Comp Drivers

                        That thought crossed my mind, packs of them in all manner of quantities. I think I'll do the bar, it's customers and myself a favor and opt for D220ti's. The budget is $150 in parts. I haven't been able to find any info on any changes or an alternate crossover, which kind of surprises me considering how many people with these JBL's seem to go this route. Are there any changes that should be made? Is it not worth the effort, eq it out? From what I read it seems like most people just drop them in and call it good.
                        Buyout MTMWW

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                        • #13
                          Re: Need some help with JBL SF15 Comp Drivers

                          Originally posted by gabel87 View Post
                          ...Is it not worth the effort, eq it out? From what I read it seems like most people just drop them in and call it good.
                          The SF15 was an entry level offering, so the merit of investing a lot of resources gets seriously evaluated and probably rejected.
                          MY observation is that drivers in entry level speakers fail more than the more costly models.
                          Even very expensive C.D. drivers fail or get damaged - that is why manufacturers offer replacement.
                          I've seen a lot of blown V.C. on other low cost horns ( like Hepner and Eminence )
                          "Not a Speaker Designer - Not even on the Internet"
                          “Pride is your greatest enemy, humility is your greatest friend.”
                          "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

                          Comment


                          • #14
                            Re: Need some help with JBL SF15 Comp Drivers

                            Yeah, makes sense. That's partly why I don't want to go through the effort of measuring them and modeling new crossovers or changes to the existing ones for the Seleniums myself, not worth my time. Other than the personal satisfaction of polishing these turds the best I can, lol. But probably like most who put any effort, however minimal, into these low end JBL's there's no hope for them shelling out for new or better speakers. So anything I can do to fix and improve the sound and their durability cheaply is as good as it's going to get. These are used for live music in a small, narrow venue, so their lack of lows isn't much of a problem. It'd be nice if they had better midrange but they are what they are. I get what you're saying about blowing horns, when you have any number of people plugging in and out, potentially dropping mic's and what not. The danger is ever present of blowing the horns regardless. Vigilance is required by the sound guy. Looks like the Selenium diaphragms are pretty cheap so hopefully they'll hold up but if the worst happens it won't be to bad. As long as it isn't happening a lot ;)
                            Buyout MTMWW

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                            • #15
                              Re: Need some help with JBL SF15 Comp Drivers

                              I put Selenium Dh200s in cabs for a bar that is nothing but hard surfaces everywhere(feedback central) where they hold regular karaoke sessions and parties and they have not blown up yet.. going on 5 year now.
                              Paul O

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