Hasty Posted August 21, 2017 Share Posted August 21, 2017 I know this has probably been discussed multiple times, but when is it suggested to put new diaphragm's in a K-55M driver? I've got a pair of 1990 LaScala's with crites 4500 xovers and CT-125 tweeters. I've had these setting aside since about November of last year, but I'm planning on hooking them back up to something soon. The only issue I ever noticed was that there were slight hints of distortion on some mid-frequency piano notes played at higher volumes. The mid-drivers have never been touched on these speakers, and these are getting close to being 30 years old. I'm just curious if the diaphragms may be ready for some tlc. Quote Link to comment Share on other sites More sharing options...
BEC Posted August 22, 2017 Share Posted August 22, 2017 There are no diaphragms available for the K-55M. I have managed to modify K-55V diaphragm to use in the K-55M, but that is a tricky procedure and probably not a good thing to do as long as yours are working. Bob Crites Quote Link to comment Share on other sites More sharing options...
MookieStl Posted August 22, 2017 Share Posted August 22, 2017 The back plate on the K-55M has been known to get loose and vibrate. This can sound like distortion at times. A little silicone caulk will hold it in place. Quick and easy fix (IF that is the problem). Worth a try. Quote Link to comment Share on other sites More sharing options...
Hasty Posted August 22, 2017 Author Share Posted August 22, 2017 I read what you did on your web site. I thought it looked doable if done carefully. I guess I'm partially asking whether the diaphragms are a part that wears out. Is there a complete driver that is an upgrade on a LaScala? Quote Link to comment Share on other sites More sharing options...
Hasty Posted August 22, 2017 Author Share Posted August 22, 2017 3 minutes ago, MookieStl said: The back plate on the K-55M has been known to get loose and vibrate. This can sound like distortion at times. A little silicone caulk will hold it in place. Quick and easy fix (IF that is the problem). Worth a try. That's possible. It wasn't like there's some blatant issue. You'd never notice it 99.9% of the time. Quote Link to comment Share on other sites More sharing options...
BEC Posted August 22, 2017 Share Posted August 22, 2017 Yes, there is a better driver, the A-55G. But, look into the plastic back plate on the K-55M. It could be loose as Mookie said in his post above. Usually that shows up as a buzz, but could possibly just cause distortion. Quote Link to comment Share on other sites More sharing options...
BEC Posted August 22, 2017 Share Posted August 22, 2017 I have not run into a bad diaphragm on a K-55M that still worked. On some very old K-55Vs, I have seen that they tend to loose output in the area below 1000hz. In that case, a new diaphragm fixes them. As they age, we may see more problems with the K-55M. Also as they age, the plastic ring you have to reuse on the K-55V diaphragm to use it as a replacement on the K-55M gets more and more brittle. When one breaks, not sure what the next move is. 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted August 22, 2017 Share Posted August 22, 2017 What about debris in the gap... Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted August 22, 2017 Share Posted August 22, 2017 1 hour ago, Schu said: What about debris in the gap... What about the driver to horn gasket? Quote Link to comment Share on other sites More sharing options...
JohnA Posted August 22, 2017 Share Posted August 22, 2017 If the drivers have not been apart, there's not much likelihood of debris in the magnet gap; it is very hard to over-drive a K-55 behind the autoformer, the other source of "debris". Check the black plastic cover and be sure the red gasket between the horn and drover is still soft and red. If not, replace and don't tighten the driver like a gorilla. Quote Link to comment Share on other sites More sharing options...
djk Posted August 22, 2017 Share Posted August 22, 2017 " When one breaks, not sure what the next move is. " 3D printer? Quote Link to comment Share on other sites More sharing options...
gary p Posted September 2, 2017 Share Posted September 2, 2017 The a55g drivers sound great in my belles. I have the same crossover and tweeter upgrades as you do. Wasn't sure my 55v drivers needed replacement. Really glad I replaced them. Soundstage is amazing. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
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.