adam2434 Posted March 17, 2022 Share Posted March 17, 2022 Hi, I made a couple posts in the thread linked below, but maybe posting in this forum will be better. https://community.klipsch.com/index.php?/topic/123955-klipsch-klf-20-loose-front-and-back-panels/ I recently picked up a pair of KLF-20 and I am curious if there are known production dates/versions that do not have the baffle separation issue due to lack of adhesion to the melamine surface, which I have been reading about. I saw a thread with someone fixing the issue on their speakers. In that thread, the photos showed that the inside surfaces of the front and back baffles were black. Looking through the ports on mine, the inside surface of the front baffles is a tan color, maybe raw MDF, not sure. Mine are medium oak, by the way, but I would not think that Klipsch would have different interior baffle colors for the different exterior veneer colors, right? This makes me wonder if perhaps some versions of the KLF series didn't have melamine on the baffles, and thus may never develop the baffle separation issue. I did test mine and I can't hear any baffle separation. Maybe I got lucky with this pair...for now. Or, maybe some versions will never develop the issue due to different materials of construction. Any thoughts or knowledge would be appreciated. Quote Link to comment Share on other sites More sharing options...
001 Posted March 20, 2022 Share Posted March 20, 2022 i posted some replies to your questions in the other thread... the issue with loose boards is not related to melamine, its the defective glue they used in KLF & KG models of this era. the larger KG 4.5 & 5.5 didnt use melamine & still had the problems indicating it is glue related. if yours dont have any noticeable issues then its likely yours dont have the bad glue. but again, its not the melamine its the defective glue that was used for a short time. as far as i know there is no known or confirmed dates/versions, since KLF didnt really have "versions" like some other models did. yes yours are raw MDF or veneer & the outer veneer type didnt dictate if melamine was used. best thing you can do is keep an eye/ear out for any signs of loose boards, maube pull a woofer or mid & feel the glue inside, if its hard & brittle & breaks off easily it "could" pose a problem down the road, if its still solid & intact it should be fine & not worth losing sleep over. Quote Link to comment Share on other sites More sharing options...
dtr20 Posted March 20, 2022 Share Posted March 20, 2022 It's not like there was a year that the issue happened, it was the luck of the draw. I've had early klf30s that really needed it repaired. I currently have consecutive klf30s. One cabinet needed to be repaired, the other didn't, at least not yet. My klf10s, didn't need it and my dad's klf20s didn't need it, but my klf-c7 did. Knock along the cabinets to see if they sound solid or if there's an almost rattle to them. Knock along the front and back panels as all as the sides, but the sides shouldn't need to ever be repaired. Quote Link to comment Share on other sites More sharing options...
adam2434 Posted March 23, 2022 Author Share Posted March 23, 2022 Folks, thanks for the input. From what I gather, there is no way of knowing whether a specific KLF speaker will have the loose baffle issue based on production date, melamine vs. MDF interior, or any other definitive production factor. Darn, I was hoping there was a way to "detective" this issue, but ok, guess not. 🙂 I will do some more testing on my newly-acquired pair of KLF-20 to see if I detect loose baffles. First round of testing did not show any signs. Quote Link to comment Share on other sites More sharing options...
SWL Posted March 23, 2022 Share Posted March 23, 2022 For peace of mind just glue those suckers and add a little front to back bracing while you're in there. It's cheap and easy to do.....and you don't need to be a journeyman carpenter to get the job done.IMO It's not necessary to remove the front and rear baffles (unless they're literally falling apart). Just finger or brush some heavy duty construction adhesive (PL Premium X3) in all the joints. Sent from my SM-G991U using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted March 23, 2022 Share Posted March 23, 2022 Yes, +1 1 Quote Link to comment Share on other sites More sharing options...
adam2434 Posted March 24, 2022 Author Share Posted March 24, 2022 22 hours ago, SWL said: For peace of mind just glue those suckers and add a little front to back bracing while you're in there. It's cheap and easy to do.....and you don't need to be a journeyman carpenter to get the job done. IMO It's not necessary to remove the front and rear baffles (unless they're literally falling apart). Just finger or brush some heavy duty construction adhesive (PL Premium X3) in all the joints. Sent from my SM-G991U using Tapatalk Sounds like a good rainy day project. After removing the drivers, are folks able to maneuver a standard caulk gun inside the cabinet to apply construction adhesive (like PL Premium) to the front and rear baffle joints? Quote Link to comment Share on other sites More sharing options...
SWL Posted March 24, 2022 Share Posted March 24, 2022 Sounds like a good rainy day project. After removing the drivers, are folks able to maneuver a standard caulk gun inside the cabinet to apply construction adhesive (like PL Premium) to the front and rear baffle joints? When I did my 30's several years ago, I just got what I could with the caulk gun and everywhere else I just shot the PL Premium on a glove or a small paint brush and worked it into the joints as well as for the added braces.I wasn't shy with it. More is better than not enough. Haven't had cabinet issues since.Sent from my SM-G991U using Tapatalk Quote Link to comment Share on other sites More sharing options...
adam2434 Posted March 24, 2022 Author Share Posted March 24, 2022 13 minutes ago, SWL said: When I did my 30's several years ago, I just got what I could with the caulk gun and everywhere else I just shot the PL Premium on a glove or a small paint brush and worked it into the joints as well as for the added braces. I wasn't shy with it. More is better than not enough. Haven't had cabinet issues since. Sent from my SM-G991U using Tapatalk Yeah, I can see why you would want to go heavy with the adhesive - because it is really acting more like a corner bracket than a joint surface bond. For a front to back brace, I'll have to see where there is real estate, but I'm thinking maybe gluing on a 1"x1" cleat to the front and back, then gluing a 1"x3" brace to the cleats. While I'm at it and the drivers are out, I'd probably also re-cap the crossover - at least any electrolytics. I've re-capped multiple speakers, including a pair of Forte 1. Quote Link to comment Share on other sites More sharing options...
SWL Posted March 24, 2022 Share Posted March 24, 2022 Yeah, I can see why you would want to go heavy with the adhesive - because it is really acting more like a corner bracket than a joint surface bond.Exactly......as well as filling any voids.Sent from my SM-G991U using Tapatalk Quote Link to comment Share on other sites More sharing options...
001 Posted March 24, 2022 Share Posted March 24, 2022 you have to remove any of the old glue before applying any new adhesive, if it looks anything like the pic i posted of the tangents it can be applied pretty heavy. & consider gorilla glue to reinforce the seams, doesnt need a caulk gun & will get into any crevices, gaps or voids much better than a PL or glue will. but either one will work, GG is cheaper too & can be used for other things. one $5 bottle will do at least 2 pairs of large speakers & have some left over. Quote Link to comment Share on other sites More sharing options...
OO1 Posted March 24, 2022 Share Posted March 24, 2022 @adam2434 ideally , you can also place wood corners with a few screws on the inside if you wanted , to make these cabs solid , glue can only do so much Quote Link to comment Share on other sites More sharing options...
SWL Posted March 24, 2022 Share Posted March 24, 2022 That construction adhesive is hard core. It ain't going anywhere. Besides, I wouldn't take a chance on running a screw into such thin walls on those cabinets. Sent from my SM-G991U using Tapatalk Quote Link to comment Share on other sites More sharing options...
adam2434 Posted March 27, 2022 Author Share Posted March 27, 2022 Did some more bass heavy music testing on the KLF-20's and could not detect any panel vibration or rattling. However, the bass output level is lighter than I would expect for such large speakers with dual 10" woofers. Also, the woofers don't have as much movement/excursion as I would expect when the volume is pushed. Not sure if this is normal. I was using a pretty beefy amp (Rotel RB-1582 at 200 watts/channel). As a side comment, I found that PL Premium 3X also comes in a 4 oz squeeze tube, which could make application easier in the areas a caulk gun can't be reached for interior baffle gluing. Quote Link to comment Share on other sites More sharing options...
001 Posted March 27, 2022 Share Posted March 27, 2022 woofers should be moving pretty good when pushing the volume & bass heavy music. try & turn the bass knob or EQ up. what kind of music are you using? might try something you may not normally listen to like.. uh, rap "music" or more modern pop or r&b that has low electronic bass. classic rock doesnt have much low bass but should still make the woofers move quite a bit at higher volume. Quote Link to comment Share on other sites More sharing options...
SWL Posted March 29, 2022 Share Posted March 29, 2022 However, the bass output level is lighter than I would expect for such large speakers with dual 10" woofers. Also, the woofers don't have as much movement/excursion as I would expect when the volume is pushed. Not sure if this is normal. I was using a pretty beefy amp (Rotel RB-1582 at 200 watts/channel). Do your 20's still have the original crossovers? Sent from my SM-G991U using Tapatalk Quote Link to comment Share on other sites More sharing options...
adam2434 Posted March 30, 2022 Author Share Posted March 30, 2022 9 hours ago, SWL said: Do your 20's still have the original crossovers? Yeah, original crossovers. I am actually going to replace the 80 uf electrolytic cap in the woofer circuit and leave the other 3 Mylar caps alone in the midrange and tweeter circuits. Also going to redo the gasket tape on all the drivers. The caps and gasket tape are already on order from Parts Express. BTW, I pulled all the drivers and crossover from 1 of the speakers and glued the interior front and back baffle joints with PL Premium 3X. Went heavy with it and used two 10 oz tubes on 1 speaker. Surprisingly, I was able to use a caulk gun for all of it, with some fancy maneuvering, including my head in the woofer holes at times, lol. I also glued in front to back braces (1" x 3" poplar) and crossed them with and glued them to the existing 2 side to side braces. So now there are 2 "T" braces. If I have time, I'll start on the other speaker tomorrow. Plan to give these KLF-20's to my son, so want to get them in good shape and ready for the next ~25 years of service for when he moves out someday. Quote Link to comment Share on other sites More sharing options...
OO1 Posted March 30, 2022 Share Posted March 30, 2022 On 3/27/2022 at 12:40 PM, adam2434 said: However, the bass output level is lighter than I would expect for such large speakers with dual 10" woofers. you're not the 1 st person to state that bass is so so with 10 " KLF 20 woofers . Quote Link to comment Share on other sites More sharing options...
Fish Posted April 8, 2022 Share Posted April 8, 2022 On 3/27/2022 at 12:40 PM, adam2434 said: Did some more bass heavy music testing on the KLF-20's and could not detect any panel vibration or rattling. However, the bass output level is lighter than I would expect for such large speakers with dual 10" woofers. Also, the woofers don't have as much movement/excursion as I would expect when the volume is pushed. Not sure if this is normal. I was using a pretty beefy amp (Rotel RB-1582 at 200 watts/channel). As a side comment, I found that PL Premium 3X also comes in a 4 oz squeeze tube, which could make application easier in the areas a caulk gun can't be reached for interior baffle gluing. I know where you're coming from. I always had complaints on Klipsch bass, rf7,20,30 bunch more. Had em'hooked to a Rotel 1068/1095, B&K, Outlaw, many,plenty power but not taking my bass to Cerwin territory. I hooked em to my Sansui 9090, you'd never doubt their impact again. You would have busted cabinets then I'm pretty sure if you pushed to hard. Be assured, they can have insane bass, even the rf7 would shock most people that have owned them with bass and punch. I sold a couple of old radios to a younger friend, Pioneer, Sansui, Project One. He called me later that evening and was gushing about his original 7's pounding out the bass. He had them hooked to an Emotiva pre and 200 watts per amp. He was, and is still going on about how it made him love the 7's again. So, just know they can perform. I don't know why newer radios don't have that sound. Heaven knows I spent a small fortune trying to find it. As usual, it was here all along.... Quote Link to comment Share on other sites More sharing options...
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