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  • NX55P suddenly sounding bad

    Hi, All;

    Sorry to bug y'all with two sets of questions in one day!  I'm prepping for my first show of the year, took my NX55Ps which I had been using as monitors and threw them up on stands, got some loaner JRX112Ms set up as monitors, ready to have a "dress rehearsal" to make sure I've got all my Ts crossed and Is dotted. (Nothing worse than showing up at a show and being short a cable .. or not knowing how to operate your equipment)

    So ... one of my NX55Ps now sounds like crap.  Something wrong with the LF driver I'm pretty sure. I have checked the configuration between the two speakers and made sure that the source feeding the bad-sounding speaker sounds fine with the good-sounding speaker. The source is just the demo track off my drum machine, through a mixer.

    The video shows me walking from the bad speaker to the good speaker and back.  They are being played VERY quietly, something like 75dB @ 1m   (people sleeping in the house).  Listen to the bass, very scratchy and jangly in one speaker and smooth as silk in the other.

    Should I bother doing anything at home, or should I just take it to the shop on Friday?  (135 mile drive each way) .. Could this be a loose connection between the amp and the driver, or something simple like that?

    Thanks,
    Wes

    <div class="signaturecontainer">--<br><br>Hammond: BC, M3, Split L111, L122 / Leslie: 51, 760 / Yamaha: DGX-620, PF-85<br><br>Follow my new band, <a href="http://DrBombay.ca/connect.html" target="_blank">Dr. Bombay</a>! We're going to be organasmic!</div>

  • #2

    Are you 100% positive it's the speaker? How have you got the signal routed? Something's not right for sure. Sounds to me like you have no "highs" coming from one of the boxes, but you're talking about "bass".

    If it is the speaker, how old is your speaker? My dealer simply hands you a brand new one over the counter, if the speaker is not more than two years old,,, no questions asked.

    Veni, Vidi, Velcro;

    (I came, I saw, I stuck around)

    Comment


    • Craig Vecchione
      Craig Vecchione commented
      Editing a comment

      Given the intermittent nature of the problem, it's possible those loose connections were the culprit. The vibration from vehicle transport can wreak all sorts of havock on wire connections. I had a JBL sub connector work itself loose after two trips in the back of my truck. One speaker of the pair just stopped working. I feared a blown driver, but the flip-flop connector that allows paired vs two-single drivers had magically popped off the retainer enough to drop out one connection. It was probably never seated. It's been fine for the last ten years.


      It's good you bought a spare, bad that the brake line blew, very lucky it didn't cause an accident.


    • wesg
      wesg commented
      Editing a comment
      It's funny how this stuff happens. I didn't even put it in the car, it failed when I moved it from "monitor" to "FOH" in my basement for the dress rehearsal for my next gig. At least, as far as I know. It could be that the fellow it was pointing at just didn't notice the LF driver problems.

      As for the brake line, I'm still amazed I'm not dead. I was in the left-most lane of a 10- or 12-lane highway moving at 70mph when not stop-and-go. I had to park my van mostly in the 3'-wide breakdown lane and call the cops: "get here fast or I'm a dead man". LOL

      Wes

    • Craig Vecchione
      Craig Vecchione commented
      Editing a comment

      wesg wrote:
      It's funny how this stuff happens. I didn't even put it in the car, it failed when I moved it from "monitor" to "FOH" in my basement for the dress rehearsal for my next gig. At least, as far as I know. It could be that the fellow it was pointing at just didn't notice the LF driver problems.

      As for the brake line, I'm still amazed I'm not dead. I was in the left-most lane of a 10- or 12-lane highway moving at 70mph when not stop-and-go. I had to park my van mostly in the 3'-wide breakdown lane and call the cops: "get here fast or I'm a dead man". LOL

      Wes

      Oh boy, I know that feeling. When I was 17 or 18 I had a '70 Camaro with a 'vette engine, Holley carb, all sorts of go-fast parts. Driving home from work, the engine stalls out in the left lane of a 4 lane highway at the top of an overpass/intersection with another 4 lane highway. There's no left shoulder...the road was built in the 30's as a WPA project. So I'm literally IN the left lane. There's no cell phones...it's 1980.


      But I did have a hammer. Got out, open the hood, spin off the air cleaner, and beat the hell outta the front float bowl on the Holley. Grab the air cleaner, jump in, crank it until the gas cleared, it started, and off I went.


      I judged it to be a 10-F-you'er (how many drivers pass and either flip you off or yell "F-YOU!!!"). It's northern New Jersey.....NOBODY stops to help....


  • #3
    It would be more easy just to swap the speakers from them instead the amps, if you managed to take the speaker from the good ones to be installed in the faulty one and if it's sounds good enough like the other working the problem is on the speaker then

    Comment


    • abzurd
      abzurd commented
      Editing a comment

      JV90 wrote:
      It would be more easy just to swap the speakers from them instead the amps, if you managed to take the speaker from the good ones to be installed in the faulty one and if it's sounds good enough like the other working the problem is on the speaker then

       

      You'll get a better view of the inside of the box if you take the amp out though and be able to test both the compression driver and woofer at the same time versus taking out both of each and swapping them (2 parts instead of 4). It's not hard at all and probably the same number of screws as removing the woofer and grill.


  • #4

    First of all you should completely swap out signal paths, don't just link through. Try and recreate the bad sound through the "good" speaker. Also cycle your jacks in case it's that. Along those lines try a different source, like a mic, and also try different input jacks. Also cycle any buttons on the cab - line/mic, 100hz cut.... And of course try the cab with and without the cut.

    DON'T open the cab up until you talk to the store and find out if that will void your warranty. And find out what your warranty covers. IIRC the used warranty coverage is different than the new - but I certainly could be wrong.

    I've seen a few NX55P's with blown woofers and intermittent tweeters, but it's hard to say without being there.

    Comment


    • #5

      I would not swap speakers and amp modules with out checking things first.  If the amp module on one is bad and putting out X amount of DC you could fry the other "good" speaker. Sounds like a rubbing voice coil to me. Take out the woofer on the bad speaker and gently push in and out and see if you hear a rubbing / scraping noise. If so it could be bad. If the woofer is bad then check the amp for DC output on the speaker leads. If the module seems to be ok hook up up old woofer first if you have one and see if it sounds more or less ok with that connected.

      Last swap the good woofer to the bad cabinet to see if it sounds ok.


      Dookietwo

      Comment


      • RoadRanger
        RoadRanger commented
        Editing a comment

        Dookietwo wrote:

        Take out the woofer on the bad speaker and gently push in and out and see if you hear a rubbing / scraping noise.


        You don't usually have to remove it - just take the speaker grill off. If you've never done the push test thing before try it on the good one first so you know what it feels/sounds like. Oh, and use two hands so you can push it evenly (and no more than 1/4 inch!).


      • WynnD
        WynnD commented
        Editing a comment
        Be gentle! You don't want to screw up the good speaker. If you feel any roughness in the cone movement, then the voice coil is toast. (Doesn't have to be open circuit for that to happen.) You should also look closely for any tears in the cone or separation of the dust cap. Those can usually be repaired with proper cement, but I'm pretty sure it will change the way the driver sounds. (Consider it an emergency treatment until you can recone or replace the driver.)

      • andertone
        andertone commented
        Editing a comment

        One thing to remember:  These things tend to rattle themselves in their plastic boxes with prolonged use.  I had to reseat one of my NX55P woofers, problem solved, same thing with the other, the HF unit was loose and had an intermittant contact.  First check is to see if the drivers are seated and sound, then go for the amp modules if the problem persists

         


    • #6
      Whatever it might be? Just remember that it can be fix, hope it would be easy to get the speaker back in action

      Comment


      • #7

        This picture is one of my yorkville EF500p speaker horn drivers. The magnet seems to screw up tight to a piece of plywood. Making it solid. The woofer is well supported as well.

        DookietwoMaster Volume Repair 04.JPG

        Master Volume Repair 05.JPG

        Attached Files

        Comment


        • wesg
          wesg commented
          Editing a comment
          Well, I was in Toronto today and the big L&M sale was on, so I stopped by the Bloor St. location. I'd been looking for another monitor for myself to replace the combo amps I'd been using, and had been considering an Alto TS110A. I bought another NX55P instead, and have long-term plans to buy more of them. Now I at least have one spare so a problem like this won't ruin the show.

          I also checked with the staff, if I crack open my problematic speaker to check all the connections I will not void my L&M warranty.

          Then I had a near-accident on the DVP, blew a brake line, and completely drained my bank account trying to get back home. What a day.

          DookieTwo, thanks for the pics. I need to crack into this NX55P this weekend, I'm curious how they will compare internally.

          Wes
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