KLF-20 Repairs and Upgrades. Looking for suggestions

grindfix

Full time hobby
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I have a pair of Black Satin KLF-20 that are NOT consecutive serial numbers but both untouched.
According to sticker on the tweeter horns, one speaker was made in March of 1998 or after and another one is from August of 1997. Newer one does not seem to have any issues but older one does.

1. Mid horn cracked from threading it too far.
2. Front (motor board?) panel is loose and wouldn't take much to remove it.

Crossovers and drivers look identical between the speakers.

My plan is to re-cap crossovers, repair cabinet(s), repair or replace cracked horn and soundproof both units.
Soundproofing is where I need some advise. Foam stuffing is different between speakers and I'm sure there are better ways to silence those cabinets. I read here that people use material called Dynamat?
Does whole inside of the cabinet need to be covered with it? Are there different thicknesses of this product?
Before I read about Dynamat I was thinking to use foam drawer liner material from Home Depot. It is about 3/16" thick but does not have adhesive side, so I was thinking to use carpet seam tape which sticks to about anything. I'd like to hear suggestions.

Tweeter diaphragms. Should I consider replacing them with Crites Titanium? Big difference?
Mid diaphragms. Anything to improve there?
Anything else?

Thanks
 
you can attempt to adhesive bond your cracked horn but it would be easier to find a replacement. If the adhesive in your front baffle is problematic then in all likelihood all you baffles are the same or are going that way. You should bite the bullet and remove all the baffles and repair them once an be done with it. If you have a Dremel tool use a small drum sander with a coarse grit and remove the melamine where ever you have a joint then you can re assemble with good old white glue (PVA) which is stronger than the wood and will last forever is dirt cheap and non toxic. I won't say more than that. You can take the opportunity to install all your bracing while the baffles are all out which makes this job an easy one.
You can apply some 1/16" thick dynamat on the back side of the mid and treble horns. If you brace your cabinet that will make it solid and non resonant. The foam inside the top portion of the box is there to damp any upper range resonance that is driven by the woofers. It is fine up there doing that job you don't need more, the woofers are damped by the reflex vents.
Switching to the Crites Ti tweeter will be a massive improvement so do that. I also use the Klipsch Ti mid diaphragm only available from Simply speakers. to me this change transforms the speaker to a whole new level. Some think you need to mod your network to include this diaphragm I do not agree believe who you like or experiment for yourself. I have listened both with and without the network and I choose not to use the network, I also modify all my drivers but that is more than most want to do or are capable of doing. You can look to further mods after you are done with your cabinets and have hew capacitors and tweeters installed and see what you think then. You should be more than pleased when you are done as these speakers are well worth the effort.
 
Thank you for your input!
Would you recommend going with Crites capacitor kit or there is a better and possibly less expensive alternative?
I already repaired cracked horn with Plastic Weld from hobby store. I will also drill 4 holes and reinforce threaded section with screws and nuts on both mid horns. I think that horn plastic shrinks with age and weight of the driver and tension of threaded nipple is too much to take.
I was thinking to dampen backs of all horns with Dynamat as well as to line all large flat surfaces with it and get rid of original foam insulation. What do you think of that plan?
 
congratula
Thank you for your input!
Would you recommend going with Crites capacitor kit or there is a better and possibly less expensive alternative?
I already repaired cracked horn with Plastic Weld from hobby store. I will also drill 4 holes and reinforce threaded section with screws and nuts on both mid horns. I think that horn plastic shrinks with age and weight of the driver and tension of threaded nipple is too much to take.
I was thinking to dampen backs of all horns with Dynamat as well as to line all large flat surfaces with it and get rid of original foam insulation. What do you think of that plan?

Congratulations on repairing your cracked your horn. Dynamat applied to your interior cabinet walls is not going to have any effect upon wall damping because the wall panel is too massive this would be a horrible waste of time and money. If you want to deal with the walls then brace them, This will push the wall resonance up above the pass band of the woofer meaning the woofer will no longer be able to cause the wall to resonate as the wall with brace work will now have its first resonant point above any frequencies which the woofer can generate. If you want to take advantage of your dynamat then place a layer of it on the inside of the woofer basket struts.
To brace your box use braces made from 3/4 inch plywood make them 1.5" wide. This width is already a little wider than optimum so any wider and you will not make a stiffer brace you will only take up cabinet volume which is a bad thing and you will gain no benefit so far as cabinet stiffness goes. Place a vertical brace on each side (attach the braces on the 3/4" edge) one on the top front to back (make sure to leave room for the tweeter magnet) leave the bottom alone you may need that space for an upgraded xover later and I like to place two vertical braced on the back baffle. That takes care of the vertical braces. Net you need to install some horizontal braces on the front baffle one below and above of each woofer and on the rear baffle above the vents and above the terminal cup. Finally you want to tie the side braces to each other and the front baffle braces to the rear braces.
You can see how removing the front and rear baffles makes this a much easier job to do. You must also remember to remove all the melamine where ever you intend to install a brace.
The caps which Bob will sell you are very good quality caps and they are all the right voltage and will physically fit the board. If you go shopping for other caps you may well end up paying more especially if you have to purchase from multiple vendors then shipping will cost you a lot and as mentioned you will need to make sure all your new parts will fit or you will incur more costs to replace them. Bob will send you great parts that fit and you will pay only one shipping charge. The caps he will sell to you are very much superior to the parts Klipsch installed stock, your call do what you think best. Hope this helps.
 
I wonder if anyone ran into this. Two out of four woofers are not centered. Voice coil rubs badly in one and slightly in another one. I believe they came from older speaker cabinet. Their dust caps look different from the ones in newer cabinet. There is no indication that woofers were re-foamed. Am I dealing with improperly centered spider or just surround? Spider does not seem to be detached as I’ve seen in Klipsch subwoofer drivers due to basket rusting. I was able to peel off the surround from the cone and can attempt to recenter using low frequency signal. What adhesive would be recommended for this type of cone?
I have good experience with paper cone reforming but never done poly type.
Thanks
 
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Here is the picture of the repaired mid horn. I did both horns same way to reinforce them.

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I was able to save my woofers. This turned out to be spider separation from the basket due to rust. I think that has something to do with the adhesive that was originally used in earlier version. Newer pair does not have any issues and glue seem so be black in color and shiny in comparison to the one with issue, where glue looks like some kind of ceramic brittle material.

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I did some cabinet repairs and bracing. I don't know if all of KLF series are made same way, but mine have front and rear panels made of compressed fiber rather then MDF. I didn't go as far as MJ suggested in his posts but did install 3 sets of X-bracing to stop panels from resonating. I did one cabinet at the time and could tell a difference slapping cabinet from outside.

I installed Crites Ti tweeter diaphragms and Crites crossover capacitors. I padded tweeter and squaker horns and inside of the woofer frame with soft 1/8" rubberized foam material. Probably not much different from Dynamat type.
Woofers are now mounted using all 8 mounting screws each. Soft foam gasket under all drivers. I used original 1" thick foam to make "hat covers" for both upper drivers to reject woofer influence and by only using 1/2 of the foam material, I guess more of the cabinet volume is now available for bass resonance.

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I really do not have a very good reference point to compare with since one cabinet had separated front baffle and both woofer spiders were partially detached. I feel that mid is too forward but highs are a lot smoother then before. I will give it some time to break new components in before doing anything else. Ti mids are possibly next.
Can anyone comment on Crites caps break-in time?
 
Moray,

Couple of questions:
1. What did you use to extend port tubes and what was the extension length?
2. I asked Bob Crites to share his experience with Ti for mids and he said that they will be louder and will require band pass mod to the crossover. I know you liked that upgrade without crossover mod. Are they in fact louder then originals? My listening space is smallish and I assume, that is the reason for mids to step forward. I'm pretty satisfied with high frequency but would like to either tame mids a little or boost bass to compensate.
3. Do you believe Crites crossover capacitors need break-in time and if so, how long? Initially speakers sounded somewhat boomy but that sound changed within an hour.

Thanks
Dmitriy
 
you can experiment with all sorts of material to extend reflex vents from paper to plastic and they will all work well, material thin enough to easily roll up is best. Remember the vents do not have to be buried in the cabinet the whole vent can be external to the cabinet and for experimenting that can be easier especially if you want to play with a vent that is too long to fit inside the cabinet.
I never measured the level of the mid diaphragms phenolic to titanium. The titanium do seem to be more dynamic so some might perceive that as louder.
All capacitors form and they change sound as they form time varies from cap to cap type. Long loud play will form your caps the fastest no matter what kind they are.
 
Moray helped me(detailed instructions) repair lose motor board and and removed all the acoustic material that the glue did not adhere to inside the cabinet and added new braces. I purchased new Crites networks and all new Ti diaphragms. Ports are still stock and SUPER happy with them. Keepers for sure.
 
This was easier, I think.
3" (3.25" actual ID perfect fit over originals) Thin Wall drainage pipe coupler $2 / pc from Home Depot + heat gun, wheel balancer cone, press and black primer. Will be sliding over originals on the inside of the cabinet.
I need more impressions for Ti mids before I pull the trigger. I wouldn't mind to spend additional $160 but is a waste if I won't like them. Did you like them with re-capped stock crossovers vs. phenolic?

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I feel that the ti diaphragms take all the speakers I have installed them in to a whole new level of performance to which the phenolic diaphragms simply cannot achieve. I believe that most of the new series of home Klipsch loudspeakers are metal diaphragms same with the pro speakers.
 
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I agree...I've not found a Klipsch speaker that I didn't think improved significantly by changing out the originals for Ti tweeter diaphragms...to include kg2, kg4, KG 4.5, KG 5.5, Quartet, Chorus II, KLF-C7...YMMV

Bill
 
Hello AK'ers! Great forum here and have thoroughly enjoyed reading this thread. I have a pair of KLF-20's I bought brand new in spring 2001, and have enjoyed for
nearly 20 yrs. I am currently looking for a full on upgrade to these. I will need to replace the tweeters completely and not rebuild- A few yrs. ago one of the K-79 tweeters stopped working. I had a smaller, older K-84
which actually fit perfectly into the cabinet, so I simply switched it out. But, not thinking about it, I tossed the old K-79 away. I now have two totally different tweeters-so I want to replace them with something new that will fit. I'm not sure if Bob Crites has tweeters that will work. Barring nothing available from Crites, I have a line on some new LMAHL V2 Tweeters with B&C DE10 drivers, which have gotten great reviews. My thought was I'd get the new mid-horn drivers and new crossovers from Crites and install along with the LMAHL V2 tweeters. In addition, I had tossed my original grills away probably 17-18 years ago after they were used as a scratching post by my cat. Another AKer had mentioned something about Klipsch still having some new "old stock" grills for the KLF's in their warehouse, and even provided the item number, #104028- which I wrote down. Well, I called them today, (800-554-7724) 1/28/20 and asked if they still had some. To my utter shock, they did! So I just bought a pair of brand new grills for my 20-yr. old speakers, and ordered a couple new Jubilee medallions for them- they did not have any KLF ones. Any thoughts or other things I might want to consider on my planned upgrades?
 
Thank you for your input!
Would you recommend going with Crites capacitor kit or there is a better and possibly less expensive alternative?
I already repaired cracked horn with Plastic Weld from hobby store. I will also drill 4 holes and reinforce threaded section with screws and nuts on both mid horns. I think that horn plastic shrinks with age and weight of the driver and tension of threaded nipple is too much to take.
I was thinking to dampen backs of all horns with Dynamat as well as to line all large flat surfaces with it and get rid of original foam insulation. What do you think of that plan?

the plastic of the horn may well become brittle with age as the plasticizer sweats out but I can assure you that these horns broke when they were new the walls are very thin the magnet assembly is heavy. They should have the mid drivers removed for shipping so they don't snap off when dropped hard. for around the home and careful handling there is no issue.
dynamat or hushmat on the back sides of the horn body and on the woofer baskets is a good plan and worth the time and money. DDynamat or hushmat is not designed to damp 3/4" mdf so that would be a very bad and very expensive idea you need brace work for that search the archives lost of info on brace work.
you need the foam or some other camping up around the horns and or on the bottom below the woofers the cavity between the two woofers and the vents must be left totally open and un damped so it can fully couple (resonate) between the woofers and the vents that is how they are intended to work but you can add damping above the woofer so long as you contrive that it stays up there where you place it.
 
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