Bp30's tweeters gone bad, any technical explanation?

Discussion in 'Speakers' started by Fernando Saa, Dec 15, 2003.

  1. Fernando Saa

    Fernando Saa Stunt Coordinator

    Joined:
    Aug 3, 2002
    Messages:
    56
    Likes Received:
    0
    I brought my Bp30's to the store I purchased them from three years ago after noticing their sound wasn't quite right after listening to some of my cd's. While listening to music I got up went close to each side of each speaker and found that sound was coming from only one tweeter from each speaker, the other two were totaly silent. The people at the store informed me later that all four tweeters had gone bad and that they didn't know what could have possibly gone wrong for this to happen; they'll be replacing them under warranty.
    Would anyone here at the Forum give me some idea as to what could have happen to my speakers? My receiver is a Pionner VSX-D608 Dolby Digital and DTS decoder unit and is rated at 100 watts per channel, I had my speakers biwired. I live in central Florida; could lighning cause a surge to travel thru speaker wires and damage speakers?, or perhaps my receiver has an electrical problem?, By the way they told me nothing was wrong with the crossover networks in the speakers. Thank you all very much for your help.
     
  2. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    24
    Location:
    NorCal
    Real Name:
    John
    If your system was hit by lightning, you would have lost plenty of other gear at the same time.

    Since it is the tweeters only and not the networks, my guess will be that your receiver is far too underpowered for these speakers, even at average listening levels. Fried tweeters is quite often caused by the amp section not being able to deliver enough power during peaks, causing distortion, which will result in damage.
     
  3. Fernando Saa

    Fernando Saa Stunt Coordinator

    Joined:
    Aug 3, 2002
    Messages:
    56
    Likes Received:
    0
    Thanks John, does that mean that I should not have bought these speakers before upgrading my receiver? I'm confused now since I've never heard about what you said before. If these speakers are supposed to handle up to 500 watts, aren't they strong enough to handle a 100 watt receiver? what about a 50 watt high current receiver like the ones Harman Kardon offers? how will I know which receiver to get so this possible scenario won't happen again? Thanks again, and a little more insight to this will be greatly appreciated.
     
  4. John Garcia

    John Garcia Executive Producer

    Joined:
    Jun 24, 1999
    Messages:
    11,571
    Likes Received:
    24
    Location:
    NorCal
    Real Name:
    John
    The thinking that the speakers can handle more power than the receiver can produce is actually kind of backwards. Yes, the speakers are capable of handling an unclipped 500 watts. I seriously doubt this receiver is capable of it's claimed 100w. I checked it's specs, and it lists 100w in surround at 1kHz, rather than 20Hz-20kHz, an indicator that the amp section is not so stout. While it will drive these speakers, if you have it up loud and experience a sudden or prolonged loud passage during a movie or music, you may reach the limit of this receiver.

    The problem occurs when the receiver runs out of oomph when trying to drive the speakers at a given volume, it creates a clipped signal (distortion). When the drivers try to reproduce the inaccurate signal, they heat up, which can quickly lead to failure, and tweeters are usually the first to go. This happened to a friend of mine not too long ago, and to me also when I bought my very first stereo receiver (fortunately the speakers had protection circuits and were easy to repair).

    More current is definitely better, and the H/Ks are conservative in their ratings, so I would say a similarly priced H/K will provide enough power, depending on how loud you are looking to turn it up. [​IMG]

    You should still be able to use this receiver for now, but the only way to avoid this again until you upgrade the receiver, is to be careful to listen for distortion - crackly or unclear sound, and turn it down until it sounds "normal". Hope that helps.
     
  5. Rory Buszka

    Rory Buszka Supporting Actor

    Joined:
    Jun 5, 2002
    Messages:
    784
    Likes Received:
    0
    The BP30s use tweeters made in Norway by Seas, model H537. I have them in one of my own speaker designs, and the sound is really, really good from them. Definitely a high-quality tweeter, and the tweeters also have high power handling for a tweeter, like on the order of 160 watts max or something.
     
  6. Steve Lucas

    Steve Lucas Stunt Coordinator

    Joined:
    Aug 12, 2002
    Messages:
    163
    Likes Received:
    0
    John is exactly right. I burned out a tweeter in my Paradigm Monitor 9's by playing movies at high volume levels...when those transient peaks come they work the amp very hard unless you have tons of headroom. The amp clips the signal and before you know it, you have burned up a tweeter.
    Ironically, the answer in this case is more power. The beefier your amp is, the easier it can reproduce those sudden peaks without distorting the signal and your speakers stay happy.

    Steve
     
  7. Ted Lee

    Ted Lee Lead Actor

    Joined:
    May 8, 2001
    Messages:
    8,390
    Likes Received:
    0
    yep...i agree with everything john already said.

    when you start blowing woofers, now that'll be something to brag about! [​IMG]
     
  8. Fernando Saa

    Fernando Saa Stunt Coordinator

    Joined:
    Aug 3, 2002
    Messages:
    56
    Likes Received:
    0
    Thanks very much gentlemen for your help. I could see you are very well experienced on this matter. Would biwiring my speakers with this receiver be advisable? I tried to follow instructions on biwiring from the Bp30's manual and I might have done something wrong. How, in your own words, do you biwire a speaker?, could this further increase my chances for driver failure?
     
  9. Ted Lee

    Ted Lee Lead Actor

    Joined:
    May 8, 2001
    Messages:
    8,390
    Likes Received:
    0

Share This Page