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Bi-Amping the JBL SR4722-X Is This Amp OK?

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  • Bi-Amping the JBL SR4722-X Is This Amp OK?

    I am in the process of setting up my amp rack with class D amp to lighten it up some and would like to try bi-amping my SR4722X tops. I already have a Crown XLS1000 (specs below) and I'm wondering if it's too much amp for the highs. The speakers HF drivers call for 60 watts at 8ohms and the XLS1000 delivers 215 watts per channel at 8ohms. It seems to me like I need a less powerful amp. I s that correct?

    I don't post often on here but I read almost everything and would like to thank you all for the volumes of very helpful information!
    http://www.myspace.com/johnnychange

  • #2
    You are kind of stuck at this level, it would be better if you had a programmable limiter in your crossover so that you could limit the power to maybe 100 watts/8 ohms. This will give you a little more time to react in the event of an accident.
    -------------------------------------------------------------------------------------------------------------------------------------------------------------------
    Former product development engineer: Genz Benz, a KMC Music/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

    Currently product development engineer: Mesa Boogie

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    • #3
      This is one of the unfortunate problems we've seen for many years now, since it became cheap and easy to get powerful amps...there's precious little available in the under-100-watt range.
      "If you don't know where you are going, you might wind up someplace else" - Yogi Berra, 1925-2015

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      • #4
        Thanks! I guess I need to start shopping. I found this Samson amp that is 66 watts at 8ohms It's funny that at 15 lbs, it's almost twice the weight as the Crown xls1000.
        Samson - Servo Series - Servo 200
        http://www.myspace.com/johnnychange

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        • #5
          http://www.ebay.com/itm/Crown-Xs-Ser...item280497616c

          The above has a little more power than you need but it has 4 channels.
          I own a few of these amps and use them in several of my racks for horn applications in tri-amp systems plus small monitors. (They are the amps with the red and yellow LED's in the center of the faceplate.)

          28lbs. with four seperate 200w @ 8 ohm channels. I have used mine for several years and they have been bulletproof.

          I have purchased four of these as used units (two of them purchased via ebay @ approximately $350.00 per unit). I'd offer the seller $300.00 and negotiate from there.

          Mike M
          Attached Files

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          • #6
            What model crossover are you using?

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            • #7
              Mike M, Thanks for the suggestion, that looks like a good amp for my four monitors. He's asking $1200 for it, $350 is way below that

              souix, my crossover is the Dbx 234xs, I plan to use stereo mode with 2 subs(SRX718) under the 2 mains.
              http://www.myspace.com/johnnychange

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              • #8
                After doing some research on the Samson I have decided that even though it is the right size amp, it may not be as reliable as I would like. So, my next question is how far above the recommended 60 watts can I safely go without going too far? Andy mentioned using a crossover to limit at 100 watts, is a 100 watt amp too much? Thank you all for your help.
                http://www.myspace.com/johnnychange

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                • #9
                  Use the limiters that are available in most DSP crossovers. Unfortunately, the 234 does not have limiters.

                  I'm not sure biamping the tops is worth the effort, frankly.

                  Note that I am a little confused, you mention biamping with the 234 using subs and tops, but then talk about biamping the tops. Not sure what you really are asking now.
                  -------------------------------------------------------------------------------------------------------------------------------------------------------------------
                  Former product development engineer: Genz Benz, a KMC Music/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

                  Currently product development engineer: Mesa Boogie

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                  • #10
                    Thanks Andy, Maybe I am overthinking my PA set-up. I plan to use my crossover in 3 way stereo mode where there are two crossover points delivering three signals: 1) a low signal for my subs 2) a mid signal for the 12" in the top speaker 3) a high signal for the tweeter in the top speaker. The main thing that has me stumped right now is finding a decent quality amp for the highs. If I am safe to use a 100 watt amp the options appear to be better.

                    Am I wrong in bi-amping(if that's the correct term) the tops? Should I just stick with passive mode using the built in crossover in the tops?
                    Last edited by johnnychange; 09-11-2015, 06:57 PM.
                    http://www.myspace.com/johnnychange

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                    • #11
                      I prefer to use amps from the same line for biamp/Triamp. If you're using xls series amps then the xls1000 would be a great choice. Because of the DSP it's good to use other xls' so all amps are delayed slightly by the DSP.



                      Amp size isn't important if you've got limiters and you're not hitting them hard. I use qsc cx502s (plx1602s) on horns, mostly jbl2447 16ohm and peavey 22xt 8 ohm (these are most similar to the 2425). The meters never get above -20db and that's just flickering mostly. So far after 8+ years of biamp I haven't lost a horn driver at all to overpowering. The clarity is nice, the difference is sutble, less so when you lean into the boxes a bit. Better clarity at higher volumes.



                      4722 has a great crossover and a rather small HF driver (2418?). I'd be less inclined to biamp and rather move up it box size. I dunno, you'll have to make the call.
                      www.rock-bot.com
                      Live-Band-Karaoke

                      bassist and sound reinforcement

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                      • #12
                        IF you are using amps with DSP, they should all be of the same series so that the latency times all match, otherwise you are introducing yet another issue.

                        I wouldn't bother biamping the top boxes myself unless there was a compelling reason to do so. The crossovers are pretty good in those cabinets.
                        -------------------------------------------------------------------------------------------------------------------------------------------------------------------
                        Former product development engineer: Genz Benz, a KMC Music/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

                        Currently product development engineer: Mesa Boogie

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                        • #13
                          Originally posted by agedhorse View Post
                          I wouldn't bother biamping the top boxes myself unless there was a compelling reason to do so. The crossovers are pretty good in those cabinets.
                          That's why I come here, the advice is spot on! Than you for saving me from myself
                          http://www.myspace.com/johnnychange

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