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DIY converting an active monitor to passive - easy?

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  • DIY converting an active monitor to passive - easy?

    Alright guys,

    We've got an old Peavey 100W powered wedge (Eurosys 12PM I think) which stopping working in a puff of smoke a few months ago. It's not worth the money to have repaired, but how difficult would it be to convert into a passive cab?

    i'm literally thinking along the lines of 'open it up, take all the electronic bits out, and run a wire from the input jack to the speaker terminals'. Then we simply plug it into a power amp with a speakon-jack lead.

    It'd obviously nice if we could use the tweeter too, but I suspect I'd need to wire in some sort of crossover for that?


    Any thoughts? Will this work or am I missing something?

    Cheers
    ► Tokai LP
    ► Peavey Windsor (modded)
    Custom 2x12 cab |Boss DS-1 | Homebrew 'Ego Boost' | Marshall Echohead | Line6 FM4 | TC Polytune | Homemade A/B box |

    Traps 6-piece hybrid drum kit | JBL 4401 monitors | BCF2000 surface www.soundcloud.com/rightontime

  • #2
    The answer to your original posted question is - NO.

    Hmmm Eurosys 12PM sounds suspiciously like a behringer model. Are you sure it's a Peavey?

    Provided your drivers survived when the amp died (often the amp will kill the drivers when it goes) then it is theoreticly possible but....... it will never sound as good or have the power handling capabilities as it did with it's active system. The factory puts a lot of engineering into amp/speaker matching, time alignment, EQing, & preset limiters that you won't have if you run it passive (Most companies do - maybe not so much behringer - maybe that's why it died :>).

    Yes to use the tweeter (it's pretty unusable without it) you would need a crossover (at least a simple capacitor to hi pass the tweeter). A DECENT crossover would probably cost you more than the box is worth.

    Carefuly check the drivers individualy (NO low end to the tweeter) and if they are usable, sell them as parts. IMHO that's the most cost effective solution.

    BTW I like your band name :>)
    J.R. Previously jrble

    See my Dog Of The Hair studio at: http://www.dogoth.com/studio/

    Quote from someone: Flat response? Get out the jack and change the tire.
    If you think "power is knowledge", you have it backwards.

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    • #3
      Yeah, I don't ever recall seeing anything even resembling the name 'Eurosys' from Peavey, but then again I know they do offer some alternative products for foreign markets. I guess it could have been a European-only product, although JRBLE is right - it does sound like a Behringer name.

      I guess it all comes down to cost and the resale value. While I agree that it might be prudent to part out the components and buy a good passive monitor, that might not be the best option where you are considering what music gear sometimes sells for in your area. If it's a really old powered monitor, it might not have the processing and precise matching to the internal components that modern powered speakers have. They may have just stuck an amp inside the monitor and called it good.

      Back in high school, I remember using some old Peavey powered monitors that were made around 1990, back when Peavey was using the black & teal color scheme. They consisted of a Scorpion 12" woofer and a little piezo tweeter with a big amp in back. There were two 1/4" inputs and a level control (maybe sensitivity control) for the (heavy) internal amp that that's it. They worked fine but were nothing to write home about. Anyway, speakers like that would be okay to modify. You won't have anything but a cheap hacked speaker in the end, but it will work. Pull the blown amp, cover the large hole with some wood, then wire up jacks. I believe the piezo was just wired off the woofer with an inline resistor.

      Of course this is in no way a slam against Peavey, a company that makes great gear at very affordable prices. The longevity and reliability of Peavey gear has been a double-edged sword. While it gives the company a great reputation for reliable gear, it also leaves the impression among some non-thinking individuals that Peavey gear is subpar. They'll compare their 30-year-old Peavey powered mixer to the new one they just bought and say "Our new Brand X mixer is soooooooo much better than the Peavey. Peavey sucks." Well, would you compare an old Apple IIe's capabilities to a new Windows machine running Windows 7? Of course not, but folks seem to do that with audio gear all the time. Peavey has fallen victim to this mentality, unfortunately.

      Comment


      • #4
        Well, would you compare an old Apple IIe's capabilities to a new Windows machine running Windows 7?


        Funny... I don't ever remember my IIe locking up... :lol
        Engineering Axiom 21: Whomever has the key should be qualified.

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        • #5
          Gotta have one more post...
          Engineering Axiom 21: Whomever has the key should be qualified.

          Comment


          • #6
            i like IIe's. i appreciated their 'machine' type of use rather than the 'environment' type of use of winders and marcintash.

            kind of like the korean war era ex WW2 army jeeps compared to the military industrial complex's hummer. i'll take the jeep please.
            band status - "its complicated"

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            • #7
              I remember the IIe's in grade school failing to load Oregon Trail and having to be restarted. Other than that they were pretty reliable.

              But... have you ever tried to burn a DVD on an Apple IIe? Or just look at a color picture for that matter?

              Comment


              • #8
                Guys, Peavey sells gear in the EU under different names than in the US.

                tele62, there's a good chance that the speaker isn't biamped, so there will be some sort of passive crossover between the amp and the speaker drivers. If this is indeed the case, you can do as you planned....yank the amp out, and run the speaker wires to a Neutrik Speakon jack on the back plate. Be sure to test for correct polarity. A 9v battery + terminal touched to the 1+ terminal (and - to the 1- terminal) should result in the LF driver cone moving outward.
                "If you don't know where you are going, you might wind up someplace else" - Yogi Berra, 1925-2015

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                • #9
                  Cheers guys, tried to sort it out and it was a ridiculously simple circuit inside - a small power amp linked directly to a no-name 12" speaker (no tweeter at all).

                  Connected the speaqker directly to the binding posts of a power amp and I got absolutely no sound either way round, not even the slightest pop or cracked. I've tried 9v battery against the terminals and nothing at all happened!

                  Which leads me to suspect that the speaker's dead, what do you reckon?




                  Exactly. My logic is, rather than spending
                  ► Tokai LP
                  ► Peavey Windsor (modded)
                  Custom 2x12 cab |Boss DS-1 | Homebrew 'Ego Boost' | Marshall Echohead | Line6 FM4 | TC Polytune | Homemade A/B box |

                  Traps 6-piece hybrid drum kit | JBL 4401 monitors | BCF2000 surface www.soundcloud.com/rightontime

                  Comment


                  • #10
                    Sounds like a plan to me. You definitely want a fullrange speaker, not a guitar speaker which is usually midrange only.

                    Eminence has the Beta-12CX, which is a coaxial fullrange speaker with a built-in HF driver. In the US it's $75 (www.usspeaker.com), and they have a wizzer cone version, the Beta-12LTA for 10 dollars less but at the expense of most of the high end response (8kHz vs 20kHz). For vocal monitors, it might not matter to you at all, and it will help fight feedback.
                    "If you don't know where you are going, you might wind up someplace else" - Yogi Berra, 1925-2015

                    Comment


                    • #11
                      Sounds like a plan to me. You definitely want a fullrange speaker, not a guitar speaker which is usually midrange only.

                      Eminence has the Beta-12CX, which is a coaxial fullrange speaker with a built-in HF driver. In the US it's $75 (www.usspeaker.com), and they have a wizzer cone version, the Beta-12LTA for 10 dollars less but at the expense of most of the high end response (8kHz vs 20kHz). For vocal monitors, it might not matter to you at all, and it will help fight feedback.


                      Cheers for the advice again, they're about
                      ► Tokai LP
                      ► Peavey Windsor (modded)
                      Custom 2x12 cab |Boss DS-1 | Homebrew 'Ego Boost' | Marshall Echohead | Line6 FM4 | TC Polytune | Homemade A/B box |

                      Traps 6-piece hybrid drum kit | JBL 4401 monitors | BCF2000 surface www.soundcloud.com/rightontime

                      Comment


                      • #12
                        open or incredibly stuck/fused into gap VC. check for continuity
                        band status - "its complicated"

                        Comment


                        • #13
                          Eminence has the Beta-12CX, which is a coaxial fullrange speaker with a built-in HF driver.
                          The HF driver is not built-in - it requires a APT-50 supertweeter and crossover.

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