KLH Model Five Restoration

[JKent]

Or try spraying on the Blue Coral while the cloth is still on. 

Staples won't puncture if you use Roy's method with thin wood strips or cut the staples.

I have not tried Gorilla fabric glue (may be worth a try). I use Aleene's Tacky Glue.

Kent

[Brad1234]

I will need to find some of the Blue Coral Upholstery Cleaner. The gorilla glue fabric glue is pretty hardcore, its $7 a tube, but very effective. You squeeze a line of it along the fabric, smash the fabric down, then separate it and set a timer for 15 mins. After it dries tacky in about 15 mins the rejoining is super strong, very limited time for adjustment but it holds super strong. I still weigh it down a couple hrs with landscape stone blocks i have to make sure it doesn't loosen while drying. And the corners are tough to glue with all the folds and cuts in fabric

[Brad1234]

I finished up my Model 5 restoration of the grills and they came out nice. I used linen fabric from Joann Fabrics, it was only around $10 and looks great!  
I have a question on the recap job for the experts, I used Audyn PP Q4 Intertechnick capacitors and double and triple checked the values and connections when assembling it, but after playing them for a while the mids just seem so much louder and overpowering the sound stage, even turned down to low setting. Is this just how 5's sound or is there possibly some explanation in the cap difference over the original caps, or resistors I could add to tone them down some?  I am playing them on a Marantz 2270 and have used other speakers in their place with no mid problem. Any advice will be so appreciated!

[Brad1234]

Update to my above post, I fixed the midrange problem with my 5's!  I isolated it to one of the speakers and spent a few hours opening it all up again and checking every connection on the xover. Nothing was wired wrong but there were some connections on the 2 level switches that looked like they might have been touching. I cleaned up the ground rivets, and put a little solder on them just in case that was the problem. I made sure all wires were clear of the chassis ground plate and put it all back together, fired it up and the mids sound normal and the tweeter is louder and clearer too. Now I can see why everyone raves about these speakers, they sound amazing!  

[FWBlack]

Your speakers look great, and you're correct, these speakers sound awesome.  Those ground rivets are an issue, on mine, I wired them all together so that the grounding was not dependent on the rivets connection to the metal plate.  Glad you got you issues sorted out.

[Brad1234]

Ok, back to my previous question on the midrange output on the 5's. I got the crossover issue fixed and mids sound great, but they are just too loud with the new foil caps and I have to turn my mid setting almost all the way down on my stereo for them to sound right. The 3 way switch on crossover just doest have enough db reduction capacity to equalize out the drivers. I was thinking if an Lpad or additional resistor in line with the mids could solve this problem?  I know if I had just gone with the basic caps this may not have been an issue. Anyone have any ideas/suggestions for reducing the mid output further on the 5's when the new caps are just too loud?

[jessiAV]

Brad,  I note that in your posted pictures your woofers have different dust caps (apparently original and black replacement). Maybe they are contributing to the difference in energy you are hearing?

[RoyC]

On 6/14/2022 at 12:30 PM, Brad1234 said:

Ok, back to my previous question on the midrange output on the 5's. I got the crossover issue fixed and mids sound great, but they are just too loud with the new foil caps and I have to turn my mid setting almost all the way down on my stereo for them to sound right. The 3 way switch on crossover just doest have enough db reduction capacity to equalize out the drivers. I was thinking if an Lpad or additional resistor in line with the mids could solve this problem?  I know if I had just gone with the basic caps this may not have been an issue. Anyone have any ideas/suggestions for reducing the mid output further on the 5's when the new caps are just too loud?

Brad,

The (2) 3 way switches of the KLH 5 affects only the tweeter's response, not the mids, so turning those all the way down will reduce higher frequencies much more than the middle frequencies. There is also no way the type of capacitors you used could have caused such a dramatic difference in the mids' response. Based on your description, an additional ohm or so of series resistance to replace some capacitor ESR would not be enough to make a significant difference. 

Frankly, I have never heard of this being an issue with the KLH 5, regardless of the type of capacitors used to replace the originals. Are you sure the crossovers are wired correctly? I know a person who connected his KLH 5 crossovers' woofer leads to the mids and mids' leads to the woofers....with obvious consequences.

Roy

 

[Brad1234]

Hi Roy, thank you so much for replying to my post!!  I very carefully checked the crossover wiring and only replaced like for like step by step in my rebuild. I have a ton of experience with electronics and feel confident these KLH 5 crossovers, though some of the most complicated I have encountered, are rebuilt to spec.

I did use the mid-quality foil caps (Audyn Q4) so maybe they brightened up the mids a lot?  But I think I fixed it, I trouble shot various ohm resistors on the mid positive lead and got the sound perfectly equalized, and it is a night and day difference!  I landed on about 1.5-1.6 ohm resistor on the mids to get the sound perfect. I had a 1, 0.27 and 0.33 ohm resistor hooked up in series for best sound quality, ordered a 1.5 ohm single resistor to put in mid enclosure next week to finally finish rebuild.

It makes sense what u said about the mid and tweeter switches not affecting the mids, I really struggled with that trying to adjust the sound. Please let me know your thoughts on my troubleshooting and solution.  

[Brad1234]

2 hours ago, jessiAV said:

Brad,  I note that in your posted pictures your woofers have different dust caps (apparently original and black replacement). Maybe they are contributing to the difference in energy you are hearing?

I have not noticed any response in the woofers pre and post xover rebuild. The woofers kick out amazingly deep bass and have been well doped to seal the surrounds and installed with the sealant rope caulk. The mid sound is coming out of the double mids and I have lowered it with a 1.5 ohm resistor. They sound amazing now!   It was a slight tweak the leveling switches were not capable of.  Lessons learned!

 

 

[RoyC]

2 hours ago, Brad1234 said:

I did use the mid-quality foil caps (Audyn Q4) so maybe they brightened up the mids a lot? 

...ordered a 1.5 ohm single resistor to put in mid enclosure next week to finally finish rebuild.

Please let me know your thoughts on my troubleshooting and solution.  

 

1.5 ohms in series will reduce the mids' output by about 1.5db...as well as lower the crossover point slightly. It just doesn't seem to equate to adjusting your mid settings "almost all the way down on my stereo for them to sound right"....which  would imply significantly more attenuation than that.

There is no doubt new caps (of any type) would have less ESR than the nasty old KLH caps, so any added series resistance will make a difference. In the end, it is only your ears that matter. Hopefully you have resolved whatever the issue was.

Roy

[Brad1234]

18 minutes ago, RoyC said:

1.5 ohms in series will reduce the mids' output by about 1.5db...as well as lower the crossover point slightly. It just doesn't seem to equate to adjusting your mid settings "almost all the way down on my stereo for them to sound right"....which  would imply significantly more attenuation than that.

There is no doubt new caps (of any type) would have less ESR than the nasty old KLH caps, so any added series resistance will make a difference. In the end, it is only your ears that matter. Hopefully you have resolved whatever the issue was.

Roy

I think the ESR maybe was it. I dont have a way to measure it as an amateur speaker rebuilder. But, the beauty of the KLH 5's is that u can hang the positive mid lead out on the baffle and test hooking up mutliple .33 ohm resistors until you get the right sound balance. It's crazy how even unhooked from the mids the speakers sound so great, guess that makes the 5 a 6 when it has no mids?  I kept trying more .33 resistors in series until the mids were balanced right. The 1.5 ohm range was when it sounded best to my ears, with 3-way switches set to normal. 

[FWBlack]

Brad - just curious if you used a meter to check the new capacitors and resistors you installed to make sure they were correct as labeled?  Maybe you received some that were not labeled correctly?  All of the ones I ordered were exact when I  rebuilt the crossovers in mine.  

But... you've got me wanting to find another set to rebuild!

[Brad1234]

I did check the capacitance of all of the new caps to make sure they were in range before installing them. They all checked out fine, in fact, I have yet to receive any caps that were not in range for the 10 sets of crossover rebuilds I have done, but still like to check them just to be sure. 
 

I know what you mean about looking for another speaker rebuild project, these KLH's were so much fun I found another set of model 6's on ebay untested for around $200, I cant wait to compare them to the 5's after rebuilding them. They are a lot simpler speakers than the 5's, should be fun, just hope they actually work!

[Brad1234]

On 6/21/2022 at 9:45 PM, RoyC said:

1.5 ohms in series will reduce the mids' output by about 1.5db...as well as lower the crossover point slightly. It just doesn't seem to equate to adjusting your mid settings "almost all the way down on my stereo for them to sound right"....which  would imply significantly more attenuation than that.

There is no doubt new caps (of any type) would have less ESR than the nasty old KLH caps, so any added series resistance will make a difference. In the end, it is only your ears that matter. Hopefully you have resolved whatever the issue was.

Roy

Hi Roy,

I ordered an assortment of resistors with recap order I was doing for some other speakers to experiment with the mids and their perfect crossover point with tweeter on my 5's. I think I found it at 2.28 ohm resistors on the mids. I tried 1.5, 2, 2.5, and 3 and just wasnt getting the balance I hoped for. I could hear it was between 2 and 2.5, hooked up a 0.27 resistor and wallah!  Perfect sync with woofer and tweeter w switches in "normal" position. Would have been a lot easier to just put an lpad on the mids maybe?  But finally I can hear the full potential of these speakers, and have the upper and lower treble available on mid switches for fine tuning.
 

It is crazy the tweeter is the only thing altered with the mid switch, but i tested it with mids disconnected and could hear tweeter changing with moving mid switch!  But also, its weird the tweeter gets louder when disconnecting the mids?  Its like the mids and tweeters are intricately wired together in crossover?  These speakers are so complicated, but so wonderful when you figure them out and restore them. The sound quality is so good now with the mids balanced. See pics of my resistor dangling experiment.