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DB tech DVA line array faults

Discussion in 'Sound, Music, and Intercom' started by tony, Jan 10, 2017.

  1. tony

    tony Member

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    Hi, I was wondering if anyone had prior expeirence with DVA line arrays. The theatre where I work bought a brand new dva line array last year and we have been getting reapeted total faults(dead amp) on various amp modules. They just go in fault and then mute for no apparent reason(with no signal input in standby) I've had to change 3 amps since they were bought. Turning off and on as the manufacturer recommends does not change anything. Yesterday, another 2 modules were in fault. By the end of the 1 year garranty, I'll probably have changed all 8 amps.(4 speakers per side)

    - they are active speakers with built-in amps
    - they have protective limiters on the amps and driverack
    - they are hung at 22'
    - there are no fans for dust to accumulate
    - 2 speakers per 15a circuit (3.3 amps each)

    Anybody with ideas or experience is welcome to give "input" ahahaha. And if anybody is looking to buy them, Don't!

    Thanks!
     
  2. FMEng

    FMEng Well-Known Member Fight Leukemia

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    Is the electrical power clean and surge protected? Is the applied voltage, as measured under load and unloaded, well regulated and within normal range? Are ambient temperature conditions reasonable? If so, that leaves manufacturing defects or a design flaw of the amplifiers. Have the dead amps been sent to the manufacturer for a postmortem failure analysis? A reputable company would want to figure out what is happening and resolve it, warranty or not.
     
  3. MNicolai

    MNicolai Well-Known Member Fight Leukemia

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    I've seen similar behavior on JBL VRX's except in my case they faulted 2 weeks after delivery. It's probably nothing you've done. With powered speakers, short of deliberately hitting them with a square wave to tweak them out, the limiters, internal DSP, and heat sensors make it pretty hard for the average user to accidentally do anything that could damage them. Sometimes there's a manufacturing issue though that spoils a batch of amplifiers. Could be a new intern on the assembly line or a faulty run of capacitors from a parts supplier to the manufacturer. You probably will not have much luck troubleshooting this yourself. With my VRX issue we went back and forth between replacing just the amp modules and replacing the entire speaker cabinets 3-4 times before we landed on a non-spoiled batch of amplifier elements. It's possible my vendor's warehouse stock was all from the same defective run.

    The thing about our industry is that a lot of our purchases from manufacturers are build-to-order. Even a Full Compass or Sweetwater is getting their warehouse stock build-to-order from the manufacturer. If you go on Amazon and buy 20 Dell laptops and there's a manufacturing defect, you may only see it in 1 or 2 of those laptops because all 20 probably didn't come off of the same assembly line one right after the other in India or China. But -- you order 20 line array speakers and there's a very good chance the products all rolled off the assembly line one right after the other and any defect in one unit got put into all of your units.

    I recommend contacting the manufacturer and beating them up about it, though you may have better luck contacting the company who sold them to you. DB Technologies isn't going to have any stake in maintaining a long term relationship with you in the way that your vendor will, and DB Technologies will have a vested interest in keeping that vendor happy so that your vendor can preserve their relationship with you.

    I haven't seen a lot of customers have great success getting manufacturers to support their product outside of the warranty but I have seen vendors strike the fear of god into manufacturers and get things taken care of. One customer saying they'll never buy a product again doesn't do much harm to DB Technologies. Dealers deciding they won't sell that product because it gives their company a bad reputation does.
     
  4. tony

    tony Member

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    Thanks for your replies!

    The power is well regulated and i've checked it thouroughly. It was my first concern. As for ambiant temperature, it is a steady 21 degrees at ceiling height.

    The company is sending me replacements on guaranty and they will do a postmorterm analysis. I will update the post when they send me their analysis.

    As for not recomending the product, it is mostly because I personnaly feel that the product is poorly manufactured and is not on par for a 40k$ system. I personnaly prefer passive jbl or ev arrays but that is purely my opinon.

    Thanks!
     
  5. FMEng

    FMEng Well-Known Member Fight Leukemia

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    I would not be surprised at that behavior from JBL, formerly owned by The Borg, also known as Harmon. I would not expect that of the smaller speaker companies, like Meyer, Renkus Heinz, Community, Danley, etc. I have heard that EAW support got very poor when Loud bought them, but they got the message and turned around real fast when sales to the touring companies tanked.

    In the broadcast world, product support is everything. If it isn't good, the company will be out of business in a few years. I can point to one transmitter manufacturer that shot themselves in the foot when they dumped the parts inventory and documentation for their older products. The company is barely on life support.
     
  6. dthomas32308

    dthomas32308 Member

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    Are the cabinets constantly powered or does the power get turn on/off as the system is needed? I've seen a few situations with powered cabinets constantly powered having premature failure so just wondering if this may be the case here.
     
  7. TimMc

    TimMc Member

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    The shop I manage has 32 DB Technologies T4 speakers, some are a year old some are 3 years old. We've not experienced this problem.

    That said, an installation close to us had an issue with 1 of their units not working, the problem turned out to be a bad input trim potentiometer or a bad EQ contour rotary switch. Tapping the amp bucket with a screwdriver handle near the controls would make it work. DB Tech/RCF replaced it under warranty.
     

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