KLH Model 5 - all bass, no mid or tweeter

[Terjetassn]

Hello!

I always had a dream of getting myself a vintage stereo set up, but never got to it. Yesterday I on a vim bought a pair of KLH Model 5. I could not test them as the woman was just getting rid of some ex-husband stuff, and the speakers were the only things left.

Either way I just hooked them up to my Technics MK1200, and the Sonos Connect:AMP. Playing Nick Drake. I got a bit disappointed as only the bass works. No midrange or tweeters Can someone help me here? Are they blown? Is it the crossovers? As you can tell I am a complete noob here.

Any pointers to how I can test / fix the issue would be great!

Terje

 

[spark1]

You can test those drivers with a multimeter by removing them from the cabinet. Use resistance (ohms) measurement. You should get around 5-6 ohms on them, or thereabouts.

If drivers are good, problem is in the crossovers. The KLH Five was designed for higher power handling, but it is still possible that someone burned them out. Seems odd that both speakers would have crossover issues affecting all three of those drivers. On the other hand, KLH used low quality capacitors...they never thought about people using these speakers 40-50 years later.

These speakers usually benefit from recapping the crossovers, but before you go to that trouble and expense you will want to determine if the drivers are in working condition.

You should also exercise the output level switches on the rear; this may bring them back.

 

[RTally]

The KLH speakers of that era need to be recapped. The capacitors in the crossover frequently fail with no sounds coming from the tweeters and/or mids. There are many threads here about restoring the KLH 5, including recapping the crossover.

On some occasions, the drivers fail. This is easily checked by measuring the resistance across the drivers. An open circuit indicates that the driver has failed. But in all my KLHs (4 pair and hoping for more), the problem with dead tweeters was fixed by recapping.

Regardless of the drivers being good or bad, the caps need to be replaced if they are original.

 

[RTally]

btw, welcome to AK. This is the place to find help.

The KLH 5 is a fine speaker. It is one the two KLH models that I am still looking for. The other is the Model 23.

PS: I see spark1 beat me by a few seconds.

 

[GD70]

Hey Terje!

First off, welcome to AK!
Second, yes, you did buy a fabulous set of speakers, that need work. Non working mids and tweeters is fairly typical in vintage KLHs. Almost always, this is due to bad, way out of spec caps on the crossovers. If you’re handy with a soldering iron, this is something you can do yourself. The second most important thing to help restore the sound is to get the correct sealer for the woofers cloth surrounds, and mids surrounds. eBay seller vintage-ar sells the sealer. I know the gent who developed the sealer, and supplies vintage ar.
I’m not going to get into all the specifics of your crossovers, but there are two versions. Earlier are all point to point soldered wires, the later version has a PCB that the caps, resistors and coils are soldered to. Once you open them up, you’ll be able to tell.
I suggest first, do a search on AK for the Fives. The recap process has been covered dozens of times, with great photo documentation, info for the various places to buy the caps, and how to go about replacing them.
Second, I suggest looking on line at lots of pics of the crossovers, and read as much as you can find so you’ll be familiar and confident to proceed with your restoration.

Once they are singing properly again, they are fabulous speakers. Well worth the effort. If any of the mids or tweeters are blown, they are pretty common and easy to find on fleabay. Both were used in other models.

I have a set, and fortunately, they were recapped just before I bought them.

Cheers, Glenn

 

[spark1]

If you don't have a meter to test the drivers, you can connect them (one at a time) directly to the speaker outputs. Make connections with the amp powered OFF...very important.
Once connected, make sure volume is at ZERO, then turn on the amp. Very gradually increase volume, and don't go very far at all...you will be feeding the drives a full-range signal, and they weren't designed for this, nor for the associated power. The idea is to turn it up just enough to see if they are working. It will take very little on the volume control to find out. THIS IS NOT A PREFERRED METHOD OF TESTING! But with proper precautions, it can be done safely. MAKE SURE THE BARE SPEAKER WIRES DO NOT TOUCH EACH OTHER.

BTW...I am assuming you have a phono amplifier in between your turntable and your Sonos amp?

 

[Terjetassn]

BTW...I am assuming you have a phono amplifier in between your turntable and your Sonos amp?

Thank you for your tip. And good catch; I do have a ProJect Tube Box DS preamp.

I just ordered a multimeter. I totally get what you’re telling me, but I’ll stay safe on this one

 

[Terjetassn]

Thank you, Glenn!

I also talked to a guy at the Stereo Workshop north of Albany, New York. He said he could take a look at them as well, but I’m sure he wants plenty money for that! People seem to rate him, so if anyone has any experience with them, let me know. i would love to take on the whole thing myself, but slightly intimidated

I will also be focusing on refinishing the cabinets, as they have a few chips and dings. Also they have clearly been in a house where they have been smoking.

Cheers!

 

[Terjetassn]

You can test those drivers with a multimeter by removing them from the cabiner.

just ordered on Amazon. Thanks!

 

[tubed]

To remove the suspense, simply apply some sound to each individual driver to let you know whether they work.
Instant gratification.
If they work then order the proper caps and a multimeter

 

[spark1]

To remove the suspense, simply apply some sound to each individual driver to let you know whether they work.
Instant gratification.
If they work then order the proper caps and a multimeter

As mentioned earlier.

 

[swechsler]

To remove the suspense, simply apply some sound to each individual driver to let you know whether they work.
Instant gratification.
If they work then order the proper caps and a multimeter

Do this carefully. You can easily blow an unprotected (i.e. with no crossover) tweeter with too much bass. If you're going to try hooking the tweeter up directly to the speaker wires, set the volume low, and only do it long enough to confirm that it is working.

 

[spark1]

Do this carefully. You can easily blow an unprotected (i.e. with no crossover) tweeter with too much bass. If you're going to try hooking the tweeter up directly to the speaker wires, set the volume low, and only do it long enough to confirm that it is working.

Also as mentioned earlier.

Approved by Senior Department Director
Department of Redundancy Department.

 

[tubed]

The multimeter is a nice tool.
However, it won't reveal any problems with sound quality, a rubbing voice coil for instance.
The only way to tell if a driver is truly functioning is to play sound through it.

 

[Terjetassn]

A couple of days later...

First of all; thank you so much for the information you have given here, and on other threads. I see both a clearer path and a more intimidating one

I got my multimeter, and according to the readings I am doing, 3 out of 4 mids show no ohm reading, 4th showing 8. Both tweeters are not showing anything

Question; When I play tested them originally no mids were playing any sound. Now I see that one is working. Is it because they were wired together that they did not emit any sound? Or can it be a combination with the crossovers not working properly as well?

Here are a few pictures I took along the way:
OhmTesting.jpeg: The one speaker showing any life.
CrossoverProtection.jpeg: It seems rare that there were the extra layer of fabric (or whatever that material is) on top of the crossovers. At least it seems noone else messed with the speakers before me.
Crossover1.jpeg & Crossover2.jpeg: This is what they look like just opened cabinet.
CorkSeal.jpeg: I've read that the cork seal sometimes can be all dust, but these seem pristine.

There is a guy in California selling refurbed 5's with an extra set of mids and tweets on Ebay. He wants $700 (including shipping as I live in NY). It seems steep to me, but he does have what I need; the extra mids and tweets... And I can learn so much on the way... Talk to me! Is it a good idea?

I had no idea I would be bitten by the "vintage speaker bug" so fast!

Thanks! Terje

 

[kfa888]

Also as mentioned earlier.

Approved by Senior Department Director
Department of Redundancy Department.

Is the redundancy of you pointing out the redundancy better that the original redundancy? No. It was really easy to just pass by until you doubled the redundancy.

 

[RossW]

If the 5 are anything like the 12 I used to have the mids are wired in series so if one is blown neither will work. The fabric is pretty standard, it keeps the fiberglass away from the speaker cones (some drivers have mesh glued to the baskets, it accomplishes a similar thing).

I would not spend that kind of money on another set of 5 just to get the mids and tweets. It's worth sending him a message, explaining your situation, and seeing if you can buy just the spare drivers. Some sellers are quite reasonable.

 

[Old Guy8]

Spending another $700 is money you likely would not get back if resold. Big heavy vintage speakers aren't often shipped due to cost and damage possibilities from insufficient packing.
I have a set of Fives.
Be patient looking for replacement drivers for fraction of that cost. Again be patient. Took me biding on two sets of mid drivers before I secured some.

Welcome to AK.

 

[kfa888]

I got my multimeter, and according to the readings I am doing, 3 out of 4 mids show no ohm reading, 4th showing 8. Both tweeters are not showing anything

Well crap, good chance those are toast if you are doing it right which it seems you are.

There is a guy in California selling refurbed 5's with an extra set of mids and tweets on Ebay. He wants $700 (including shipping as I live in NY). It seems steep to me, but he does have what I need; the extra mids and tweets... And I can learn so much on the way... Talk to me! Is it a good idea?

No! WAY to much. You can buy completely refurbished ones for a third of that. Or WAY better speakers for half that.

I had no idea I would be bitten by the "vintage speaker bug" so fast!

Thanks! Terje

Welcome, this stuff is FUN!!! Learn more by reading here, buy speakers that need repair for almost free and have at it. It's a really fun hobby. Soon you will have a small pile of speakers because, hey, speakers. Ha ha ha.

 

[coonmanx]

A couple of options. Find the drivers used and tested on the Bay. Or talk to a place like Simply Speakers or Midwest Speaker or equivalent and find out if there are newer drivers that will work. Could even be a way to upgrade. I did just find some used mids a minute ago on Ebay.

Depends on whether or not you want to keep everything original or just get them going. Personally I have no problem with putting in newer drivers as long as the parameters match up well. And tweeters are cheap. Even some decent domes.