Tweeter level mismatch

Discussion in 'Speakers' started by Nathan W., Apr 20, 2004.

  1. Nathan W.

    Nathan W. Stunt Coordinator

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    This is basically a rant, so please bear with me.

    I went and picked up locally a pair of early '90s DCM CX-27 monitors that I got off Ebay. During testing I removed the acoustic lenses (two metal screens with felt between them) that's in front of the top woofer from both speakers to inspect the driver in action. The tweeters are mounted in the center of this lens and I noticed one tweeter was not OEM with a totally different magnet structure, although a very close match on the front, so I missed it during pickup.

    I'm using these speakers for my computer's sound so I fed them a 10Khz sine wave one at a time and measured the tweeter's output with a Radio Shack analog sound meter right up against the tweeter's grill. The OEM measured 5Db louder. I found some tweeters locally at an electronics store that were basically identical, including the magnet structure, 'cept these were rated at 100 watts max and the OEM 40 watts max. So I replaced both tweeters to ensure a matched output level and one still measures 4Db louder and swapping speaker outputs on the receiver made no difference.

    I'm guessing the culprit is mismatched crossovers in the speakers.[​IMG] What do you think it is? I'll live with it, but it still bums me out knowing this - plus it's audibly noticeable at times.
     
  2. Joey_V

    Joey_V Second Unit

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    did the guy on ebay advertise this "tweeter replacement"? if not, maybe you can still return the product. i try to refrain from buying speakers from ebay... unless it is brand new - second hand speakers are just not the same.

    try to return it.
     
  3. Bill Blank

    Bill Blank Stunt Coordinator

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    You could try contacting DCM for OEM replacements. You have to be cautious buying ANYTHING on Ebay and ask a lot of questions.

    Bill
     
  4. Nathan W.

    Nathan W. Stunt Coordinator

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    It's possible that the guy I got them from is the same guy who replaced the OEM tweeter, but maybe not. I actually do have an OEM replacement on the way from DCM, but they really jacked up the price on it. The replacements I bought look identical to the OEM unit and are rated for 100w max versus 40w max for the OEM (both made in Taiwan, probably at the same factory). My replacements were 5 bucks each. I have a pair of the smaller and slightly newer CX-17 bookshelf with the same tweeter 'cept these tweeters are shielded by a small bucking magnet, so the OEM coming may be shielded too. Still, $20 for this unit is way too high.

    I don't think the OEM unit will help since my replacements are identical to each other and still have a 4Db difference between them. I shoulda tested them before installation with no crossover - may have left the factory mismatched.

    The speakers actually sound great. If I didn't sit so close to them I probably wouldn't even notice the tweeter output level differences. I think I'll just keep the OEM that's on the way for future tweeter burnouts, if that ever happens.

    HERE'S another pair on Ebay that are slightly newer, (mine have an Oak woodgrain vinyl finish and a full length grill) but with the same driver complement and layout. These models are an in-between size - too big for a bookshelf and too short for floor placement requiring short stands.
     

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