Defective AV15

Discussion in 'Home Theater Projects' started by Denis P, Oct 6, 2003.

  1. Denis P

    Denis P Extra

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    I bought four AV15s during the recent preorder and one of them is defective. John, at Stryke, has told me to ship it back to TC Sounds for a rebuild and I'm wondering what kind of turn around I can expect. Does anyone have experience under similar circumstances?

    The problem I'm having is that one of the four drivers makes a very noticable ticking sound in synch with the movement of the cone (no, it is not bottoming out. It is not nearly that loud). It does not show up until moderate excursions (~ .5 - 1.0" p-p). My test setup is all four drivers mounted in my IB manifold sitting on the floor. This is a test setup and the manifold is not installed in the attic so the drivers are acting like OB not IB. I've got all four drivers hooked up in series with one coil driven (the other open)for an effective impedance of ~8 ohms. I'm driving this from one channel of an AudioSource amp rated at 150 watts into 8 ohms. The ticking is very noticeable at very low frequencies from 10 hz to 25hz and only one driver makes the noise. As you raise the frequency it starts to sound like a motor boat. I took the bad driver out of the manifold and drove it alone while I held it in my hands(lower power ~ same excursion) and it is definitely coming from the one driver and not the speaker cables flapping around. I've checked above and below the spider with a flashlight and found no obvious cause. I also looked into the back vent and also saw nothing. The other three drivers work fine.

    I'm thinking that there is either some foreign object getting in the way of the voice coil or the coil is mounted off center and is nicking the poll piece at moderate excursions. I'm shipping it out tomorrow. Is there anything else I should look for before I ship?
     
  2. Greg Yeatts

    Greg Yeatts Second Unit

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    Are the wire tinsel leads striking the Aluminum cone? This would make a ticking noise. Just a guess.
     
  3. Denis P

    Denis P Extra

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    Good guess Greg, but that's not it (although that is exactly the kind of sound I'm getting). The AV15's have the leads woven into the spider so that can't happen.
     
  4. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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    Call TC Sounds (number on their website; I cannot access it right now), and talk to MaryAnn. As long as they have the parts in stock, the turn around will be very quick.

    I was held up with mine because they lost my drivers during their move, and the parts were not available to build completely new drivers.

    Brian
     
  5. Bryan Michael

    Bryan Michael Supporting Actor

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    can you wire the av 15 like that? and what is the down side? do you decrease the powerhandling or anything else like that?
     
  6. DustinDT

    DustinDT Agent

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    I talked to Mary Anne Last week about a AV-15 rebuild that was my fault. She said that there was only one person doing the rebuilds and they had recieved an unusually high number of speakers back in for rebuilds so it might be a while. They recieved my speaker on 9-12 and I got the email the first week in October. I wouldn't expect to see your woofer anytime really soon.

    D
     
  7. Denis P

    Denis P Extra

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    Bryan - Leaving the second coil open ~ doubles Qts and cuts power handling ~ 25%. You can "tune" the Qts by putting a resistor across the second coil. Look at the white paper on RDO on the Adire speaker site for more details.

    Dustin - That is bad news about the delay. It is actually pretty annoying to wait months for the preorder then get a speaker DOA and then have to wait weeks or months more for a repair instead of just getting a replacement. I know it's one of the risks with dealing with a small company but next time I think I might stick with a larger company, like Parts Express.
     
  8. Rob Formica

    Rob Formica Stunt Coordinator

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  9. Richard Little

    Richard Little Stunt Coordinator

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