Quiet_Hollow Posted August 24, 2012 Share Posted August 24, 2012 Acetone cleaned up any remaining shellac and hardened glue from the surfaces. Cleanliness is godliness here. Bits of adhesive are easily scattered everywhere when cleaning off the old remains. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 24, 2012 Share Posted August 24, 2012 Finally, I cleaned the gap using Bob's suggestion of folded Post-It note adhesive. One driver had a surprising amount of random pieces in there, the other was nearly spotless. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 24, 2012 Share Posted August 24, 2012 If you don't mask off the plastic when using Loctite 380, this is what it will do to the ABS material when it cures. The resultant vapor will deposit itself on nearby surfaces. [:|] A "very quick" wipe with a rag dipped in Acetone and the cap was back to normal appearance. Wear gloves! The combination of cyanoacrylate and ABS is nasty. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 24, 2012 Share Posted August 24, 2012 All good to go! Quote Link to comment Share on other sites More sharing options...
Guest " " Posted August 24, 2012 Share Posted August 24, 2012 it's always good to see a DIY thread......is locktight 380 a glue or is that the stuff used on nuts and bolts? Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 24, 2012 Share Posted August 24, 2012 It's very similar in formula to super glue. It's definitely not a thread-locking compound. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 25, 2012 Share Posted August 25, 2012 A few other tips for working on these. I put index marks on everything before diving in and removing things. That way, I knew the original orientation of the parts, how far to torque the screws, and how firm to tighten the driver onto the horn. Below is how I clocked the driver. By my eye, "factory tight" is about an 1/8th of a turn further clockwise, from the point where you can feel the driver contact the new gasket. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 25, 2012 Share Posted August 25, 2012 I marked everything. Screws, air chamber, throat, and magnet Later I could remove the marks using a q-tip dipped in rubbing alcohol. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 25, 2012 Share Posted August 25, 2012 I was uneasy about separating the throat free-hand (with the diaphragm still attached) from the magnet. It's a tight fit, it takes a bit of force as the magnet wants to hold everything together, and there's the opportunity to crush or drag the voice coil if I wasn't extremely careful. Making some locating pins out of 2" 8-32 socket-head cap screws (with the heads cut off and ground smooth) really worked nice for removal and assembly of these two components. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 25, 2012 Share Posted August 25, 2012 Sealing the leaks from the rear cap and driver / horn junction is NOT a trivial maintenance item, IMHO. [8] Air leaks in any horn is a bad situation. In the bass bin, they will lead to poor performance and blown drivers. In the compression horns, they manifest as irritating distortion and skewed frequency response. The sonic improvement in the midrange is blatantly immediate given the basic nature and minimal cost of the repair. [:|] The most noticeable effect is the increased midrange SPL's. Over the last few weeks, it hadn't dawned on me that I was listening to the entire system about 6-10 dB hotter than normal, just in order to hear dialogue. With everything sealed up, it's back to normal levels. I went from VOL -54 dB back down to VOL -66 dB It also brought back that characteristic smoothness in the mid's. [Y] Quote Link to comment Share on other sites More sharing options...
Marvel Posted August 25, 2012 Share Posted August 25, 2012 Did you clean up the felt or replace it? Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 25, 2012 Share Posted August 25, 2012 The felt happened to be in very good condition. I opted not to attempt to replace it because I only fully disassembled one driver, and I'm uncertain if replacements are even available. The other one, I left glued together per Trey Cannon's guidance, and just fixed it's debonded outer edge. The felt was glued in there pretty well. I imagine trying to remove it would have destroyed it entirely. Before I put everything back together I made sure it was as clean as possible...picking off any random debris that it had accumulated, but I left the hardened shellac on there and applied my adhesive right over the top of it. Quote Link to comment Share on other sites More sharing options...
Marvel Posted August 25, 2012 Share Posted August 25, 2012 I looked at the pic again... I hadn't noticed the three 'fingers' that hold the felt. I thought it was some of the glue. The felt itself does look to be in good condition. You did a great job cleaning off the old shellac. Nice job! Bruce Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted August 26, 2012 Share Posted August 26, 2012 Nice job! Thank you Bruce. It certainly sounds wonderful having their mid range performance back to normal. I thought I'd lost a good friend there for a few weeks. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted July 26, 2014 Share Posted July 26, 2014 Finally got this problem in action for y'all. I'll be posting a video of the subsequent repair as I get done editing and rendering the rest of the footage. 3 Quote Link to comment Share on other sites More sharing options...
cradeldorf Posted July 26, 2014 Share Posted July 26, 2014 (edited) So that's what that damn noise is I keep hearing from my midrange squakers... been driving me crazy!!! I also had to remove the plastic rings around my klf woofers because the frames rusted allowing the black paint to come loose that the glue was stuck to holding the rings on... I say we hunt down the idiot who decided glue was the wave of klipsch's future and glue him to a tree!!! Edited July 26, 2014 by cradeldorf 1 Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted July 26, 2014 Share Posted July 26, 2014 I say we hunt down the idiot who decided glue was the wave of klipsch's future and glue him to a tree!!! I've personally owned three pair of La Scala. All six horns had K55M, and all six eventually suffered the same buzzing problem. The only speakers I have that didn't have de-bonded K55M drivers are the pair of HIP. They appeared to have been repaired at some time in the past with a very good glue. The K55M are certainly worth fixing / keeping IMO, because once repaired, they sound really good. Quote Link to comment Share on other sites More sharing options...
Sancho Panza Posted July 26, 2014 Share Posted July 26, 2014 Thanks for the newly refurbished topic! Quote Link to comment Share on other sites More sharing options...
Sancho Panza Posted July 26, 2014 Share Posted July 26, 2014 Have K-55-V on my 1980 La Scala. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted July 26, 2014 Author Share Posted July 26, 2014 That video says it all. Great post! Quote Link to comment Share on other sites More sharing options...
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