This will be a set of instructions for replacing the diaphragm in the following Klipsch tweeters.
K-76, K-63, K-74, K-75, K-76, K-79, K-83, K-84, K-85, K-88, K-90, K63, K74, K75, K76, K83, K84, K85, K88, K90
These all use the same diaphragms and all can use either our Poly or Titanium diaphragms.
This is a K-74 tweeter with a bad original diaphragm.
We can measure the resistance at the tweeter terminals. A good one will read about 8 ohms and a bad one will read open or infinite.
OK, Let's get inside this tweeter. Remove the three nuts holding the tweeter together.
Remove
the old diaphragm from the magnet assembly. Notice that this old original phenolic diaphragm has a
damping pad inside it. You do not
have to be concerned with that.
The new diaphragm does not need it.
We
need to clean out the magnet gap.
Sometimes there will be pieces of the old coil or the coil former inside
the gap. I use a sticky note pad
folded with the sticky out on both sides.
That will be run around the gap to get out any debris that might be in
there. One exception to that is
that sometimes the manufacturer of the tweeter may have put ferro-fluid inside
the magnet gap. Ferro-fluid is a
solution of magnetic particles in oil.
If that is in there (you would immediately know since it is an oily
looking nasty mess) just leave it alone and replace the diaphragm. It would be impossible to get all of it
out. It is in there for increased
heat transfer to cool the voice coil.
This
is a new Poly type diaphragm.
Installation of the Titanium is the same. You will find that there is one place that the diaphragm
mounting holes perfectly fit over the locating screws and pins. If it doesn't go on easy in the
position you first choose, rotate it around to another position.
