Hi folks, I recently acquired vintage Infinity 61 MkII with bass drivers in need for refoaming, but when I got home I noticed that tweeters are blown too. I opened them up and saw right away that connecting wires were broken. I managed to connect them and that's when the puzzle started.
First off, I measured resistance that seemed too low (0.4ohm) for a tweeter that is supposed to have 8ohm impedance and 5.5ohm dc resistance:
https://www.toutlehautparleur.com/tweeter-a-dome-audax-tw010i1-8-ohm-bobine-10-mm-facade-74-mm.html
I inserted it in the box and barely noticed the difference - it was playing very low volume. I replaced it with similar sized seas prestige and the highs volume immediately became normal. I repeated the same process with second one, exactly the same behaviour.
Could it be that coil is shorted inside, on both of them, at exact same point?
First off, I measured resistance that seemed too low (0.4ohm) for a tweeter that is supposed to have 8ohm impedance and 5.5ohm dc resistance:
https://www.toutlehautparleur.com/tweeter-a-dome-audax-tw010i1-8-ohm-bobine-10-mm-facade-74-mm.html
I inserted it in the box and barely noticed the difference - it was playing very low volume. I replaced it with similar sized seas prestige and the highs volume immediately became normal. I repeated the same process with second one, exactly the same behaviour.
Could it be that coil is shorted inside, on both of them, at exact same point?
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As you say 0.4 ohms is plain wrong, you should have seen something around 5-6 ohms as per the Re in the linked spec sheet.
Old age may have taken its toll, and the ferro-fluid may have become a conductive sludge I do not know if you can dismantle this tweeter and clean out the ferrofluid as it's a pretty compact assembly with not much room for any mistakes during dismantling.
Old age may have taken its toll, and the ferro-fluid may have become a conductive sludge I do not know if you can dismantle this tweeter and clean out the ferrofluid as it's a pretty compact assembly with not much room for any mistakes during dismantling.
Shorting a turn in a magnetic circuit doesn't just stop a part of the winding from working, it has a more severe effect. I would suggest replacing it.
The coil and the fluid are a total mess. I need to find a replacement but it's not in production any more. It seems that this is the tweeter, rebranded for Infinity:
https://www.toutlehautparleur.com/tweeter-a-dome-audax-tw010i1-8-ohm-bobine-10-mm-facade-74-mm.html
I replaced it temporarily with this one that I had in drawer:
http://www.seas.no/index.php?option...e&id=88:h1397-04-27tafncd&catid=45&Itemid=239
and the speakers sound great, but would still like to find something closer to original.
https://www.toutlehautparleur.com/tweeter-a-dome-audax-tw010i1-8-ohm-bobine-10-mm-facade-74-mm.html
I replaced it temporarily with this one that I had in drawer:
http://www.seas.no/index.php?option...e&id=88:h1397-04-27tafncd&catid=45&Itemid=239
and the speakers sound great, but would still like to find something closer to original.