Delicious2 Posted May 25, 2016 Share Posted May 25, 2016 I've got midrange distortion/buzzing/breakup on one Khorn and not the other. It's especially noticeable on certain tracks/instruments. The diagnostic tracks I've been using are: Bill Douglas' Earth Prayer from The Absolute Sound Hearts of Space collection - the clarinet is highly distorted on many of its notes. Pat Metheny's This Belongs To You from The Unity Sessions - Metheny's opening guitar playing is very distorted on some notes. I've pinned it down to the driver by connecting in different ways so I know it's not the driver/adapter/horn combo, not the crossover (ALK universal), and not the amp. As a final check I swapped the K-55-M driver from the other Khorn to the troublesome one and the distortion went away. As I see it my options are to: repair defective driver replace defective driver replace both midrange drivers with known good K-55-Ms on the assumption that if one has gone bad the other may be going too replace both midrange drivers with upgrades such as TAD assuming that the Eliptracs and ALK universals can accept this Note: I don't want to go to active crossovers at this time. Please advise. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 25, 2016 Share Posted May 25, 2016 Have you made sure that the driver is secure on the horn and that the washer isn't bad? Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted May 25, 2016 Share Posted May 25, 2016 Check the back cover of the K55M to see if the glue has loosened. miketn 1 Quote Link to comment Share on other sites More sharing options...
Delicious2 Posted May 25, 2016 Author Share Posted May 25, 2016 Wow, you folks are fantastic! 15 minutes and I've got knowledgeable experienced replies. What a forum. The driver distorts unattached to horn/adapter/rubber washer so i don't think it involves them at all. The back cover doesn't appear loose in any way. Thanks Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 25, 2016 Share Posted May 25, 2016 The back cover doesn't appear loose in any way. Put your hand on it while it's making the noise and see if you can make it stop by applying light pressure. Quote Link to comment Share on other sites More sharing options...
Delicious2 Posted May 25, 2016 Author Share Posted May 25, 2016 The back cover doesn't appear loose in any way. Put your hand on it while it's making the noise and see if you can make it stop by applying light pressure. No difference. Light pressure with a pencil on the bug screen also makes no difference. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 25, 2016 Share Posted May 25, 2016 It could still be the rear chamber seal. https://community.klipsch.com/index.php?/topic/148013-k-horn-help-blown-mid/ Quote Link to comment Share on other sites More sharing options...
Delicious2 Posted May 25, 2016 Author Share Posted May 25, 2016 (edited) It could still be the rear chamber seal. https://community.klipsch.com/index.php?/topic/148013-k-horn-help-blown-mid/ thanks, that's an interesting read especially the part about the driver being a "pneumatic device". I have it opened up and don't see anything clearly wrong around the diaphragm part or the magnet part. The gasket that joins the two is certainly a hard plastic not soft or compressible at all. Is this the "driver o-ring" referred to in post #12 of the other thread? FWIW these are 1990 Khorns. None of the screws holding it together were loose. Edited May 25, 2016 by Delicious2 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 25, 2016 Share Posted May 25, 2016 I believe the o-ring they referred to is used where it seals to the horn. Was there a seal or o-ring there when you took it apart? Does the other driver have one there? Has the driver just started doing this or are the speakers new to you? I'm not seeing much wrong there. Be sure you clean the gap where the coil goes. You can use the sticky part of a posted note folded over. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 25, 2016 Share Posted May 25, 2016 The gasket was probably a fiber type that has hardened over time. It definitely needs to make a good seal there. Quote Link to comment Share on other sites More sharing options...
Delicious2 Posted May 25, 2016 Author Share Posted May 25, 2016 I believe the o-ring they referred to is used where it seals to the horn. Was there a seal or o-ring there when you took it apart? Does the other driver have one there? Has the driver just started doing this or are the speakers new to you? I'm not seeing much wrong there. Be sure you clean the gap where the coil goes. You can use the sticky part of a posted note folded over. I've had these for several years and I just noticed this one distorting recently. There is a hard rubber o-ring where the driver threads to the adapter/horn. The other Khorn has that also. As noted in the other thread these o-rings partially block/narrow the opening. Is it beneficial to replace these with o-rings with a larger inner diameter that doesn't narrow the opening? Thanks for the tip about cleaning the gap. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 25, 2016 Share Posted May 25, 2016 I can't see where it would hurt to change the size slightly. Do both drivers Ohm the same? Quote Link to comment Share on other sites More sharing options...
Max2 Posted May 25, 2016 Share Posted May 25, 2016 I believe the o-ring they referred to is used where it seals to the horn. Was there a seal or o-ring there when you took it apart? Does the other driver have one there? Has the driver just started doing this or are the speakers new to you? I'm not seeing much wrong there. Be sure you clean the gap where the coil goes. You can use the sticky part of a posted note folded over. I've had these for several years and I just noticed this one distorting recently. There is a hard rubber o-ring where the driver threads to the adapter/horn. The other Khorn has that also. As noted in the other thread these o-rings partially block/narrow the opening. Is it beneficial to replace these with o-rings with a larger inner diameter that doesn't narrow the opening? Thanks for the tip about cleaning the gap. You can get the gaskets with the correct ID hole that wont obstruct the output from Bob Crites. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 25, 2016 Share Posted May 25, 2016 Sorry, the O-ring referenced in post 12 is probably the gasket you see. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 25, 2016 Share Posted May 25, 2016 I'll bet that gasket is too hard to seal. Kind of like a valve cover gasket that randomly starts leaking oil. The gaskets get old and hard and just quit sealing over time. Quote Link to comment Share on other sites More sharing options...
Delicious2 Posted May 25, 2016 Author Share Posted May 25, 2016 Happy news and a puzzle. Thought I'd put the driver back together and hook it up. Off the horn/adapter lack of distortion was encouraging. Fully reassembled this Khorn sounds as good as the other one! I think you're right Carl that the gasket wasn't sealing properly. Perhaps just reseating it and carefully torquing in a star pattern got the seal back - at least for now. As to the hypothesis that this happened because the gasket got old and hard it's interesting that Bob Crites has no problem recommending the reuse of an old gasket when replacing the K-55-M diaphram: http://www.critesspeakers.com/rebuilding_a_k-77m.html Are these gaskets available anywhere if needed? And what about my TAD question? Could I upgrade to those TD-4002s as a step on the way to eventual k402s? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 26, 2016 Share Posted May 26, 2016 No idea on the TAD. Maybe someone else will chime in. Glad it's fixed! Quote Link to comment Share on other sites More sharing options...
mungkiman Posted May 26, 2016 Share Posted May 26, 2016 Happy news and a puzzle. Thought I'd put the driver back together and hook it up. Off the horn/adapter lack of distortion was encouraging. Fully reassembled this Khorn sounds as good as the other one! I think you're right Carl that the gasket wasn't sealing properly. Perhaps just reseating it and carefully torquing in a star pattern got the seal back - at least for now. http://www.critesspeakers.com/rebuilding_a_k-77m.html Are these gaskets available anywhere if needed? Any decent hardware store that sells gaskets for garden hoses... Quote Link to comment Share on other sites More sharing options...
Delicious2 Posted May 26, 2016 Author Share Posted May 26, 2016 Happy news and a puzzle. Thought I'd put the driver back together and hook it up. Off the horn/adapter lack of distortion was encouraging. Fully reassembled this Khorn sounds as good as the other one! I think you're right Carl that the gasket wasn't sealing properly. Perhaps just reseating it and carefully torquing in a star pattern got the seal back - at least for now. http://www.critesspeakers.com/rebuilding_a_k-77m.html Are these gaskets available anywhere if needed? Any decent hardware store that sells gaskets for garden hoses... I don't think it was the o-ring shaped washer-like rubbery gasket between the driver mouth and the adapter/horn that was causing the issue. I think it was the hard plastic gasket shown in the photo surrounding the diaphram. Does anyone sell those? It'd be interesting to compare a "new" one to these 25 year old ones. Quote Link to comment Share on other sites More sharing options...
Deang Posted May 26, 2016 Share Posted May 26, 2016 You can't go TAD with that network, you would need to go Extreme Slope. There is no diaphragm replacement for the K-55-M. If you can afford them, a pair of BMS 4592-mid drivers would be killer with that horn. Quote Link to comment Share on other sites More sharing options...
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