Replacing tweeters?

Discussion in 'Archived Threads 2001-2004' started by Joe Tilley, Dec 7, 2002.

  1. Joe Tilley

    Joe Tilley Supporting Actor

    Jan 1, 2002
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    I have an a Polk set up using a CS400i center & RT55i's for everything else. My problem is I cannot stand the Tri-Laminate tweets in these things at all. They are just simply too damn harsh sounding to me. I don't know if this is just the nature of these tweeters or something with the crossover design.
    I am used to speakers that use silk type tweeters so this could be cause for some of my problem.
    Anyway my question is would it be possible to change the tweeters out for something like a silk dome without changing the crossover or, maybe some kind of mod to the crossover to help tame it down a little or both? I have thought about getting a pair of silk domes from Scan-Speak or Morel & giving them a try & see what happens but I just wasn't sure if this would be a good idea.
    I'm not concerned with having to modify the bezel or killing my warranty or any of that so that is not of concern, I just wont something a little smoother sounding.

    By the way I should mention that I tried out a pair of the newer RTi70's in my home as a comparison to my RT55i's & they sounded much smoother & less harsh than my 55's in the high end. If I could even get the sound they had I would be happy.

    Thanks for any advice.
  2. Brett DiMichele

    Brett DiMichele Producer

    Sep 30, 2001
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    What other gear is in your chain? From my experiance if you
    don't have the absolute best of everything (including the
    media) then you will hear the flaws. Metal domes don't
    smooth over bad recordings, they faithfully reproduce how
    lousy they actually do sound..
    Silk domes just round off the harsh edges of the media or
    the amplification or the source transport IMHO.
    If CD is when you get the harsness try a better CD Transport
    like the Ah! Njoeb 4000, if it's DVD related a better DVD
    Transport may be in order..
    Or perhaps it's just the room treatments and speaker placement
    it's self.. Experiment with aiming of the speakers, you can
    always align the speakers differently to tone down harsh
    spots in the high frequencies. And if the walls are extremely
    reflective you might want to try dampening those surfaces
    with some nice tapestries or hanging some real paintings or
    dedicated acoustic treatments.. Or even turn down the gain
    on the Tweets... There is nothing wrong with cutting the
    DB on the Trebbel if your tweeters overpower the rest of
    the deal, it just shows that the room is very reflective
    and is boosting the high frequencies.
    There are times where my full Titanium Domes sound harsh
    and it's on bad music recordings, On good media they sound
    absolutely wonderful. And they would sound so much better
    if I had GOOD components.. Using my Panny CV-51 as a CD
    Player going through an Onkyo 787 Receiver is hardly "Good"
    for 2 Channel...
    Now what I want is this...
    CD transport: Ah! Njoeb
    Preamp: Symphones Tube LineStage
    Amp: Parasound HCC2000?? (5 channel beast, whatever the model is...)
    that shortens the path to the speakers considerably and with
    much better equipment! [​IMG]
  3. Rob Rodier

    Rob Rodier Supporting Actor

    Jul 11, 2002
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    I don't know if you can summerize all of the characterisitcs of different tweeter materials quite as easily as was done above. There is going to be good and bad to be found with all different designs.

    Playing with the position was a good suggestion. If that doesn't work than you might try putting a small piece of toilet paper over the driver. It sounds stupid, but has helped me tame hot tweeters in the past.

    Using a different driver will definately give you a different sound. However, you are going to change everything from frequency response to impedance and sensativity. It is not an easy task to successfully pull off. But again who knows, you may get lucky.

    Best of luck

  4. Brett DiMichele

    Brett DiMichele Producer

    Sep 30, 2001
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    I respect your opinion but can I ask 2 questions?

    #1: Have you ever heard what could be described as a "Laid Back" Ti or Alum or Ceramic Tweeter?

    #2: Have you ever heard a truly "Bright" Silk or AeroGel or Doped Fabric Tweeter?

    I don't often generalize like that, and I am sure there
    could be exceptions to the rule but from my experiance and
    the experiance of most others, that generalization does hold
    some water.

    Anyway take it easy!
  5. Michael R Price

    Michael R Price Screenwriter

    Jul 22, 2001
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    Provided the tweeters are of decent quality, the crossover is what really determines the tone of your speakers. If you would like to change the sound of your tweeters to be a bit less offensive, first try playing with positioning and toe-in (to potentially reduce the output of the highest frequencies). Then, you can try to contact Polk technical support and ask them if there are any modifications you could make to the crossover to give the speaker a smoother treble. This would usually involve wiring up a couple resistors and maybe capacitors for each speaker.

    Additionally, you may have a faulty low-pass crossover that is letting higher frequencies get through to the woofers, which tend to not sound very good when played out of their intended range.

    The equipment you're using could be causing harshness, but not usually that much. And since different speakers did not have this problem, it's probably because of your speakers.
  6. Manuel Delaflor

    Manuel Delaflor Supporting Actor

    May 25, 2001
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    Another type of "correction" for harsh highs would be this little box ADE-24 You will find a review here on the "tweaks" forum here on HTF and lots more on Audioasylum and over the Usenet.
  7. John Garcia

    John Garcia Executive Producer

    Jun 24, 1999
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    Real Name:
    I have to agree with Brett's first question of what else is in the signal path and how are they connected? You may be looking at this backwards - feeling that the speakers are the problem without considering many other factors mentioned, such as placement, room treatments, etc...

    The electronics can play a decent roll in what you hear. What are you using as a music source, and is it connected analog or digital? (The ADE will not help if you are using analog, AFAIK) What mode(s) are you listening in? What receiver?

    As for changing out the drivers, it is not just a simple matter of detatching one tweeter and dropping another in. You would have better luck building your own speakers, because there are so many small things to consider in speaker design that you might as well start from scratch.

    Vifa, Scan-Speak, Morel, Focal, etc... all make great drivers, but as noted, the real key is the crossover design and that is not the simplest thing.

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