I keep blowing tweeters Help!!

Discussion in 'Archived Threads 2001-2004' started by Richard Cook, Nov 21, 2002.

  1. Richard Cook

    Richard Cook Stunt Coordinator

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    Hi gang
    Over a period of time, I have managed to damage 3 pairs of HF units, usually as a result of sudden peaks in the sound program.
    The most recent one was 3 weeks ago while watching Ghostbusters. When Dana opens the refrigerator there is a sudden loud vibrato. This succeeded in causing my tweeters on the front mains to start buzzing thereafter. I've since replaced them care of the spare parts dept at Tannoy (They're R3s) but my question is: Why does it keep happening, and how can I prevent it?
    Any suggestions would be appreciated as it's getting expensive [​IMG]
    Many thanks in advance
     
  2. BrianWoerndle

    BrianWoerndle Supporting Actor

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    What are you powering them with?
    How loud are you listening?
     
  3. Claude M

    Claude M Stunt Coordinator

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    get a fuse in the circuit
     
  4. Haru

    Haru Stunt Coordinator

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    I am betting that your amp/receiver doesn't have nearly enough power to cope with the demand and is clipping on the peaks.

    If not that, then you've simply got the level set too high.

    most likely, its a combination of the two.
     
  5. Jerry Klawiter

    Jerry Klawiter Screenwriter

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    Changing your last name may help[​IMG]
    Sounds as they are over powered with lots of distortion, Cooking them.
     
  6. Rob Rodier

    Rob Rodier Supporting Actor

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    It is most likely happening because you either have too much or too little power going to the drivers. Most likely not enough. The amplfifer is being driven to hard and it clips sending a very distorted ugly signal to the tweeters. This squared wave is more than the tweets can handle.

    -IF- this is the problem than you will need a bigger amp, or more efficient speakers. You could also just listen at a lower level.

    -rob
     
  7. John F. Palacio

    John F. Palacio Supporting Actor

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    I addition to the other suggestions, I would contact Tannoy to see if the crossovers are defective, specially since you are on your third set of tweeters.

    Best regards.
     
  8. Claude M

    Claude M Stunt Coordinator

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    how long did you go before blowing the first set of tweeters?
     
  9. Bill Blank

    Bill Blank Stunt Coordinator

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    As others have mentioned, it's likely that you're not feeding them enough juice. It's very hard to blow a tweeter by using too much power than it is to blow one with too little power as wierd as that might sound. Your amp doesn't have enough power reserves/headroom to deal with these peaks thus forcing it to "clip" damaging the tweeters as a result. Invest in a more powerful amp. Affordable models with HUGE reserves are available from NAD and Rotel.

    Good Luck!
    Bill
     
  10. Ted Lee

    Ted Lee Lead Actor

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    too little power = clipping = blown tweeter
    too much power = blown woofer

    you're cranking your receiver louder than it can handle.

    plain and simple.
     
  11. Darren_T

    Darren_T Second Unit

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    Yup, you are definately clipping. I blew 3 of my 5 tweeters listening to Metallica at obsurdly high levels with my Receiver amplification. That was my lesson, I bought two amps after that and have had no problems since. My ears give out before the amps or speakers do now.

    Darren
     
  12. Phil Iturralde

    Phil Iturralde Screenwriter

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    FYI: Interesting reading ...
    Danger: Low Power: (204kB PDF file): Information on one of the most common causes of speaker failure -- (under powering).
    Phil
     
  13. Richard Cook

    Richard Cook Stunt Coordinator

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    Thanks Guys

    The amp a 5.1 input converted Yamaha DSPA 990 is rated at 65w per channel and the speakers are the Revolution R3s which on paper handle 30w to 150w.

    I'm not playing it terribly loud, around 1/4 to, but it seems that I keep getting caught out by the sudden peaks in 5.1 programs. Interestingly, it has happened only with DD material and not DTS which seems to be smoother somehow. Anyway, it looks like I need to seriously investigate a new Amplifier. Any recommendations in the £600 ($900) region?

    Thanks again
     
  14. Haru

    Haru Stunt Coordinator

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    65wpc with an 89db sensitivity speaker? You're almost certainly suffering from a lack of power. I am betting that you don't have a subwoofer, or even if you do, you're running the R3s full range. Which means when you get a peak, your receiver simply doesn't have power to supply enough power for the peak demands and thus clips severly, toasting your tweeters.

    Add in the fact that few multichannel amps, particularly somewhat older ones, are able to reach the rated power per channel when all channels are simultaneously driven. So, if you've got a 5 channel set up, and the peak hits in all channels, the amp's front channels probably don't even have 65wpc to deliver.

    from my days in the UK in the mind '90s I recall a fair amount of amplifier snobbery. There seemed almost a belief that powerful amps, unless really posh pieces, are brutish and not as refined and polished as more moderate amps. SE models from Denon and Marantz seemed designed to feed this madness. So I can imagine people assuming 65wpc in the front being adequate.

    I had a 20wpc NAD 320 powering a pair of B&W 301s and this worked very well in my TINY TINY london flat, but in a larger room, the system worked well only on the most dynamically undemanding material. I imagine 20wpc would be more than enough if I was driving a 104db sensitivity klpischorns, but I wasn't.

    You need a more powerful amp. Get one that is verified to be able to produce atleast 80watts per channel when ALL channels are driven simultaneously. Add a subwoofer too.
     
  15. Richard Cook

    Richard Cook Stunt Coordinator

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    Thanks Haru

    It looks like you've hit the nail on the head, I'd better start saving.

    I've had the amp since 1997 and had it upgraded to a 5.1 input by Videotec a couple of years back. I'am running a Sub a PDR10 and yo'ure right, the speakers are set to large! This has to be because the sub is being picked up form the Yamaha's Sub out. If I took it from the processor I would not have control over the sub volume.

    What are your feelings on the more recent Yamaha Amps such as the DSPAX 1 or 2?

    Thanks again
     
  16. Bill Blank

    Bill Blank Stunt Coordinator

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    Richard,
    I highly recommend you check out Rotel's RMB-1075. It costs $1000 US so should be around your price range in punds. It's rated at 120w and has VERY nice reserves for demanding peaks. I've tested it by running all speakers full-range on Private Ryan and it handled it with ease. FYI, my speakers are all rated at 90dB sensitivity, my room is 13' x 15' x 8'.
    http://www.rotel.com/products/rmb1075.htm
     
  17. Rob Rodier

    Rob Rodier Supporting Actor

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    Richard,

    New or used?

    -rob
     
  18. Richard Cook

    Richard Cook Stunt Coordinator

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    Hi Rob,

    Problem now solved. I went out on Saturday and put the plastic down on a brand new Denon AVR 2802. Lots of headroom and all the extrar facilities I need and a good price (by UK standards anyway). Only problem was, this morning my wife was trying to watch Breakfast TV and nearly blew the speakers completely. She had the amp switched to DVD with the TV on. She then kept turning up the volume to near maximum without me realising it! She called me and said "I can't get this %*@@£$ TV to work". I told her what the problem was, hit the TV button and nearly got blown out of my seat. Fortunately I hit the volume down button immediately and no damage done. I think!! So a lesson to be learned by us all I think!

    Thanks guys for all your help. Especially Haru who hit the nail on the head. (Thread now closed)
     
  19. Adam LH

    Adam LH Auditioning

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    ------------------------------------------------------
    I told her what the problem was, hit the TV button and nearly got blown out of my seat. Fortunately I hit the volume down button immediately and no damage done. I think!! So a lesson to be learned by us all I think!
    -----------------------------------------------------
    Richard that was hilarious! [​IMG]
    I can just imagine the fright that your wife would of got!
    Why can't our wives just leave our amps alone????
     

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