Jump to content

Lascala midrange failure


maxsdad

Recommended Posts

I finally got to take my newly acquired LSI's home & hook 'em up. Two or three songs into the test run, I heard a buzzy rattle come from the right rear, but it was fine on the next song. I thoght maybe it was just some stuff shaking on the wall, but later I noticed that there is no sound coming from the midange horn (K-55 w/AL crossover).

I have less than zero tech experience, so I'm coming to the well of knowledge - any ideas?

Link to comment
Share on other sites

Disconnect the driver leads, and put an ohm meter on it. A 16 ohm driver ( which it is) should read about 11 ohms.

A "0" reading, you have a problem with the driver.

If the driver is around 11 ohms switch it with the driver in the other LaScala ( just un-screw it). If the driver works in the other LaScala then start checking the conections in the network.

If you don't have an ohm meter, just switch the drivers.

  • Like 1
Link to comment
Share on other sites

I would agree with Mike C. Checking connections is by far the most common problem.

If that doesn't work, you may indeed have an intermittent failure of the voice coil. If it has stopped working entirely by now, the ohm meter should show "infinite" ohms.

I think Q-Man mistyped here. He meant infinite rather than zero? Naturally.

Digital meters sometimes show "OL" or the like for infinite or off scale high. It will be whatever is on the display when the meter is set to ohms and leads are connected to nothing. That is infinite ohms.

It is rare that the reading would be zero ohms (dead short) in the case of a failure.

I'm always suspicious when members come in and have problems with newly purchased used equipment. The thought is that the seller was unloading the stuff because it had some problem.

Wm McD

Link to comment
Share on other sites

I almost forgot! I stole my second pair of La Scalas because one or more of the drivers in one of them didn't work. It was a poor solder joint in the Type AL network (dreadful, replace it soon) let a wire come loose. I got it working by sticking the wire under the correct screw terminal.

Link to comment
Share on other sites

Thanks to all for the input. Both K-55M drivers are going to Bob Crites for new diaphrams and coming home with fresh AA crossovers. As to the suspicion re: used stuff, not to worry - I got a great deal and planned to relace the AL's anyway. I am still way ahead on cost and a very happy camper!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...