Max D Posted August 26, 2019 Share Posted August 26, 2019 Hello Klipsch Community, Please forgive my nativity and lack of basic technical knowledge here I wondered if someone might be able to pinpoint an issue i'm having and possibly offer some advice. All i know is that I have a pair of 1980 khorns with AK2 crossovers and they have had one owner before me. They are generally in very good condition however we have used them at high volume for parties that may have taken its toll. I've recently noticed that one speaker has noticeably less fidelity in the top ends. The crisp tingles of high hats sound great on one but a little muddier on the other. I tried switching the top Cabinets (not sure thats the correct terminology? ) from one bottom cabinet speaker to the other to rule out any wiring or amp issues feeding into the speakers but the issue remains. What could be the issue and how would one go about fixing something like this? I've seen bob crites has AK2 crossover repair kits for $120 but im unsure how easy this is for a leyman to do or if this is the way to go or if the problem could be pinpointed further. ( I have soldered before but have laughably little electrical understanding but Im keen to learn how these brilliant things work, what's doing what etc) Many thanks for your help in advance Max 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted August 26, 2019 Share Posted August 26, 2019 Welcome to the forum. Loosen and tighten all screws on the crossover before you do any further diagnostics to see if that makes a difference. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted August 26, 2019 Share Posted August 26, 2019 The other thing is cover over the tweeter then subsequently the midrange with a pillow or something to see if you can isolate the issue to a particular driver not working. Quote Link to comment Share on other sites More sharing options...
babadono Posted August 26, 2019 Share Posted August 26, 2019 When you switched the "tophats" (the midrange and tweeter horns) the problem stayed in the same speaker or moved with the tophat? Quote Link to comment Share on other sites More sharing options...
Max D Posted August 26, 2019 Author Share Posted August 26, 2019 @babadono The problem moved with the top-hat. Quote Link to comment Share on other sites More sharing options...
avguytx Posted August 26, 2019 Share Posted August 26, 2019 So on the top hat that sounds dull, disconnect the mid driver wire and see if anything is coming out of the tweeter. If there is, it "could" be the crossover capacitors or it could be potentially a tweeter diaphragm. To isolate the tweeter would require having to swap it out with the known good tweeter and see if it sounds worse, and vice versa. But doing it this way lets you know if it's driver related or crossover related or connections. Personally, I would make sure I tested all mid and high drivers, made sure all of the crossover contacts are clean (disconnecting them one at a time and cleaning them a little), etc., before throwing money at them. Find out what the problem is first. Quote Link to comment Share on other sites More sharing options...
babadono Posted August 26, 2019 Share Posted August 26, 2019 Starting to sound like a blown tweeter. Quote Link to comment Share on other sites More sharing options...
Emile Posted August 26, 2019 Share Posted August 26, 2019 14 hours ago, Max D said: one speaker has noticeably less fidelity in the top ends Hi Max, Welcome to the forum OK; they are "kaput." So, buy a new pair and I will take care of disposing of the old ones. No charge Just kidding ... yes, most likely a blown tweeter diaphragm. Very easy to replace ... instructions are on Bob Crites' website. Suggest you replace both. (And, as per most other posts, listen to each driver ... just use a tube like from an empty paper towel roll.) Or you can just replace the tweeters (see https://critesspeakers.com/prices-other_stuff.html ). If it is not the diaphragm, you can sent the xovers to Bob and he will redo them for you. Good luck, Emile Quote Link to comment Share on other sites More sharing options...
Max D Posted August 26, 2019 Author Share Posted August 26, 2019 Fantastic, Thanks guys for all your advice will try these this evening Cheers max Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted August 26, 2019 Share Posted August 26, 2019 Yes, I agree that the blown tweeter is the likeliest culprit. If you are comfortable identifying the leads that run to the tweeter (it should be obvious), then disconnect those at the crossover side (take picture so you don't forget). Now the crossover will be out of the loop for the next test. Use a volt meter (does not need to be fancy) and set in on "Ohms". The measure will either be a few to several ohms (more than 2 but less than 20), OR it will read "open" (or no continuity). If the tweeter is blown - it will read "open". If it is "open" then check out Bob Crites' web site (known as BEC on this forum). I assume the tweeter will be stamped K77 (maybe with a letter suffix) on the back. If it is not, then someone may have messed with it in the past. Good luck, -Tom Quote Link to comment Share on other sites More sharing options...
JohnA Posted August 26, 2019 Share Posted August 26, 2019 I think "blown" might be a little overstated since the tweeter still works, but it may well have a damaged voice coil. The diagnostic would be to swap the offending tweeter to the other cabinet of swap in a known good tweeter and see if the sound changes. If it improves the tweeter is damaged. If not, the crossover is damaged. The DC resistance of a good K-77-M should be 7.2 ohms +/- a few 10ths. Since yours works, I'd expect to see that. The cheapest way out is a diaphragm replacement. And more careful throttle control. Another is a $300 tweeter upgrade. 😳 I run and recommend Fastrac tractrix tweeter horns and B&C DE120 drivers. DE111 drivers look like good candidates, too. Both should be tough enough for a heavy throttle hand. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted August 27, 2019 Share Posted August 27, 2019 16 hours ago, JohnA said: I think "blown" might be a little overstated since the tweeter still works, but it may well have a damaged voice coil. The diagnostic would be to swap the offending tweeter to the other cabinet of swap in a known good tweeter and see if the sound changes. If it improves the tweeter is damaged. If not, the crossover is damaged. Did I miss where it was stated the tweeter was working, just at a lower level? Quote Link to comment Share on other sites More sharing options...
glens Posted August 27, 2019 Share Posted August 27, 2019 Never said yet one way or another. I'm surprised nobody suggested a paper towel core to determine driver function. Everything else mentioned would work well, but it all requires at least some more effort. I enjoyed the bit about "throttle hand." Things with hand throttles are fun. And usually relatively high performance. (Or is there no such thing as "high" performance - either something has performance or it doesn't?) 1 Quote Link to comment Share on other sites More sharing options...
Max D Posted August 28, 2019 Author Share Posted August 28, 2019 Hi Guys, So I unscrewed the tweeter can now say confidently that no sound is coming out of it. : ( Would this be the case if it was just the diaphragm that was kaput? Its a shame I have a party in long island this saturday where we are taking our soundsystem and am panicking a little. I can get a diaphragm replacement for then and give that a whirl but failing that anyone know of any places in the New York region that could supply a replacement K77 tweeter at short notice? Cheers Max Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted August 28, 2019 Moderators Share Posted August 28, 2019 Welcome and good luck. 11 minutes ago, Max D said: Hi Guys, So I unscrewed the tweeter can now say confidently that no sound is coming out of it. : ( Would this be the case if it was just the diaphragm that was kaput? Yes, it's what vibrates to make the sound......clean and check connections even if it looks clean it can have a film on it, lightly sand a little on the connection, can't hurt. See if you can get one delivered before Saturday, diaphragm of the whole tweeter. I know nothing about NY . Quote Link to comment Share on other sites More sharing options...
babadono Posted August 28, 2019 Share Posted August 28, 2019 6 minutes ago, Max D said: Would this be the case if it was just the diaphragm that was kaput? Yes of course. Not much else in the apparatus that can fail. Just go whole hog and get Bob Crites replacement CT125 or CT120 or Eliptrac tweeters from ALK engineering. That's my humble recommendation. Otherwise you will just blow them again, don't ask how I know this Quote Link to comment Share on other sites More sharing options...
babadono Posted August 28, 2019 Share Posted August 28, 2019 On 8/26/2019 at 9:28 AM, babadono said: Starting to sound like a blown tweeter. Of course blown tweeters make no sound Quote Link to comment Share on other sites More sharing options...
Max D Posted August 28, 2019 Author Share Posted August 28, 2019 Wow its amazing how swift you guys are, Like Klipschorn paramedics! Thanks. So hear your advice about the upgrades from crites to stop it happening again but for the sake of speed and for this one off party would these work in theory? ( I know they are not ideal but the only chance i have for repair by saturday it seems) https://www.amazon.com/Diaphragm-ST350-T350-Klipsch-K-77/dp/B00CT9QBPI I also have some heresys as a back up to compensate but would obviously want the horns singing properly if possible. Cheers Max Quote Link to comment Share on other sites More sharing options...
Blvdre Posted August 28, 2019 Share Posted August 28, 2019 2 minutes ago, Max D said: Wow its amazing how swift you guys are, Like Klipschorn paramedics! Thanks. So hear your advice about the upgrades from crites to stop it happening again but for the sake of speed and for this one off party would these work in theory? ( I know they are not ideal but the only chance i have for repair by saturday it seems) https://www.amazon.com/Diaphragm-ST350-T350-Klipsch-K-77/dp/B00CT9QBPI I also have some heresys as a back up to compensate but would obviously want the horns singing properly if possible. Cheers Max I'm guessing your Heresy's don't have a k-77 tweeter? If so, you could just do a swap. Quote Link to comment Share on other sites More sharing options...
Max D Posted August 28, 2019 Author Share Posted August 28, 2019 No they dont but im also borrowing from a pal so Id be reluctant to do the surgery. Quote Link to comment Share on other sites More sharing options...
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