KLH 12's - another hole in my KLH collection filled . .

[Carlspeak]

I just upgraded a pair of 12's Contour XO's. Didn't go over the top like Kent did with the Auricaps. It was just a basic upgrade that was badly needed after checking the ESR's and uF's on those brown jobs.

[GD70]

On 1/2/2008 at 0:57 PM, JKent said:

Hi Vern

Thank you for the compliments and your comments.

Yes--I had not noticed the wafers on the switches, but there is a difference between my all-npe xover and the mylar/npe one I just finished.

Also did not notice the penciled SN on the plywood, but now that you mentioned it, the xovers that have the "brown wafer" switches are marked in pencil "#240" and "#263." I did not see numbers on the "white wafer switch" plywood. There was a date, hard to read (Sept something) and I see I covered it with Goop to glue down the caps

Interesting note on CR's take on the Twelves vs AR3a's. I don't think the Twelves get the respect they deserve! They are essentially identical to the well-

regarded Fives, but with bigger cabinets so they go deeper. That asset is also a liability.

I bought mine for $100 with local pickup, and that included a KLH Eighteen tuner and an old speaker selector switch! Only problems with the Twelves were:

Missing 3 knobs, terrible sound because of bad caps, a few minor nicks and scratches, tired-looking grille cloth.

They now sound great with the new caps. I'm in the process of refinishing the cabinets and patching the veneer in a couple of places. Not sure what to do about the grille cloth. I have the metal logos but have not reinstalled them yet.

Your comments about the paucity of KLHs in your neck of the woods is interesting. Of course, in New England they were very common. I notice a lot of Dynaco speakers on ebay come from Canada. Guess Dynaco did a better jo of marketing up North!

Yes--the speakers are sometimes sold without the crossovers. Hard to imagine, unless buyers are opting for external electronic crossovers. Expensive, but

probably nice. As I mentioned, I plan to sell one pair of crossovers (don't need two!) so I hope I can recoup the cost of the caps and knobs. Originally I had bought some nice inexpensive retro-style knobs in Rat Shack (shown in one of my previous posts), since 3 of the originals were missing. But the second pair had (only) 3 original knobs, so now I have one complete set!

Could have used that schematic! Maybe then I would have bought the right number (and value) of caps!

Here's a photo of one Twelve. Not finished yet. The xover was moved for the photo but is normally attached to the back with Velcro. More work to do on the finish. New cloth needed. Reinstall logos. Too bad these are in the hall OUTSIDE my rec room!

Kent

They look great! The cloth is in pretty good condition, personally, I'd leave it as is. The veneer looks fantastic too!

[GD70]

On 1/2/2008 at 0:57 PM, JKent said:

Hi Vern

Thank you for the compliments and your comments.

Yes--I had not noticed the wafers on the switches, but there is a difference between my all-npe xover and the mylar/npe one I just finished.

Also did not notice the penciled SN on the plywood, but now that you mentioned it, the xovers that have the "brown wafer" switches are marked in pencil "#240" and "#263." I did not see numbers on the "white wafer switch" plywood. There was a date, hard to read (Sept something) and I see I covered it with Goop to glue down the caps

Interesting note on CR's take on the Twelves vs AR3a's. I don't think the Twelves get the respect they deserve! They are essentially identical to the well-

regarded Fives, but with bigger cabinets so they go deeper. That asset is also a liability.

I bought mine for $100 with local pickup, and that included a KLH Eighteen tuner and an old speaker selector switch! Only problems with the Twelves were:

Missing 3 knobs, terrible sound because of bad caps, a few minor nicks and scratches, tired-looking grille cloth.

They now sound great with the new caps. I'm in the process of refinishing the cabinets and patching the veneer in a couple of places. Not sure what to do about the grille cloth. I have the metal logos but have not reinstalled them yet.

Your comments about the paucity of KLHs in your neck of the woods is interesting. Of course, in New England they were very common. I notice a lot of Dynaco speakers on ebay come from Canada. Guess Dynaco did a better jo of marketing up North!

Yes--the speakers are sometimes sold without the crossovers. Hard to imagine, unless buyers are opting for external electronic crossovers. Expensive, but

probably nice. As I mentioned, I plan to sell one pair of crossovers (don't need two!) so I hope I can recoup the cost of the caps and knobs. Originally I had bought some nice inexpensive retro-style knobs in Rat Shack (shown in one of my previous posts), since 3 of the originals were missing. But the second pair had (only) 3 original knobs, so now I have one complete set!

Could have used that schematic! Maybe then I would have bought the right number (and value) of caps!

Here's a photo of one Twelve. Not finished yet. The xover was moved for the photo but is normally attached to the back with Velcro. More work to do on the finish. New cloth needed. Reinstall logos. Too bad these are in the hall OUTSIDE my rec room!

Kent

They look great! The cloth is in pretty good condition, personally, I'd leave it as is. The veneer looks fantastic too!

[JKent]

15 hours ago, GD70 said:

They look great! The cloth is in pretty good condition, personally, I'd leave it as is. The veneer looks fantastic too!

Thanks. That was 8 years ago. I really like them but had no room so I sold them to a friend of a friend who lives in town (at a slight loss I'm sure). He did ask me to replace the cloth so I re-did them in the excellent 18-count linen from 1-2-3 Stitch. Don't have a photo of the speakers with the new cloth but here are the grilles. I suspect the linen is better than the double-layer boucle + black scrim.

A couple of years ago the speakers suffered a blown tweeter and a woofer problem. I replaced the tweet and sent it to Bill LeGall for expert repair. Also treated both woofer surrounds with Roy's butyl sealant and added fuses. I see the current owner from time to time and he (and his wife) are still happy with them.

[GD70]

Nice that you still get to hear them once in a while.

the grills look great!

[ReeferDude]

Hi all, joined this place when I picked up my Model Twelves.  Nice place round here.

 

I took the plunge and did my own set of contour boxes on my newly acquired pair of 12s.  Truth be told, it was my first attempt at something more that single cap speakers.  I think I did ok.  The sound fantastic on my Fisher 400.  What an excellent speaker.  I had been running EPI M180s with new caps and fresh surrounds.  The KLH are superior across the board....and the EPI are no slouch!

Thanks to @JKent for posting something so thorough.  Much appreciated!

 

 

I was on a role so I capped a Silvertone 9315 amp too.first amp ever too.   Worked...was a good day with the iron, especially for a rookie.

[Guest amarjr1]

Looking for a good tech to recap model 12 crossovers. any recommendations? picked up cap and resistors but cant find time.

[JKent]

21 minutes ago, amarjr1 said:

Looking for a good tech to recap model 12 crossovers. any recommendations? picked up cap and resistors but cant find time.

PM me if you want me to do them.

-Kent

[JKent]

amarjr1 did contact me, so here's another KLH Model Twelve re-cap/re-'sistor. The first box had some problems. As members here may know, I always take out the 5w resistors and replace them with 10w minimum. Well, the first box I looked at had two THREE watt resistors in there!

amarjr1 had supplied the electrolytic capacitors and nice Mills 12w resistors. I needed a couple more than those supplied so there are 2 Vishay 10w resistors (the black ones) and one generic 15w (the white one). Those are what I had on hand.

The old capacitors were shot! I tested them all and here's what I found:

• 50uF  tested 111uF
• 50uF  tested 133uF
• 2 x 4uF tested 0.002 & 0.001uF
• 2 x 4uF tested 6.8uF & 7.3uF
• 2 x 2uF tested 0.2 & 0.2uF
• 3uF tested 0.27uF
• 2 x 4uF tested 5.92 & 5.94uF

Here's a photo of a finished box and an original

[JKent]

Another pair complete. Caps in the 2nd box were as bad as the first: 

• 50uF tested 121.8uF
• 50uF tested 112.4
• 2x4uF tested 0.464 & 0.228
• 2x4uF tested 0.002 & 0.001
• 2.4uF tested 0.002 & 0.001
• 2x2uF tested 0.072 & 0.10
• 3uF tested 3.63 (this was the ONLY cap of the lot that was anywhere near spec!)

Don't have my Twelves any more so I can't test the contour boxes, so fingers crossed

Here are before & after pics (2 before, 3 after). The cabinets were good with just a couple of chips and some paint marks. One faceplate had a couple of dings. The body & fender work is "OK"--not perfect. I stripped off the old lacquer and gave them a couple shots of new.

[ra.ra]

Nice work by JKent, as always.

Despite the fact that this multi-level contour crossover concept did not particularly catch fire in the 60's-70's hi-fi era, I find myself somewhat enamored with this squarish floor-standing speaker model and its separate control device. My understanding of the KLH Twelve is that it is a three-way speaker product (including two mids, totaling four drivers), with crossover frequencies at 500Hz and 4000Hz.

I am curious about a few things. Regarding the control box casing, is this a thin metal shell that is covered in faux vinyl or is it a thin walnut veneered plywood? And the control dials: do they just rotate about 90 degrees between + and -, with the dot representing a hypothetical "flat" response? And the rear screw terminals: I assume the two-screw terminal is the amplifier connection, but how is the four screw terminal connected to the driver cabinet?

The circuitry of this device sort of bewilders me, and my questions are based on the labeled frequencies at each dial on the front panel. With KLH literature stated x-o frequencies at 500 and 4000, is this an accurate understanding of the four dials: left dial controls woofer and very lowest Hz of the mids; second dial controls lower Hz of mid; third dial controls higher Hz of mid and lowest Hz of tweeter; and right dial controls the highest squeaks and brushes of strings and cymbals?       

Great pics from ReeferDude, too, and welcome aboard to CSP. But....what exactly is a reefer? Is it like a capacitor?...or a resistor?....or an inductor?...or a potentiometer? 

[JKent]

Yeh--I always liked the Twelve. Just didn't have room for them.

• The cover of the box is thin plywood with walnut veneer. I wish these posts were still numbered but if you go back 1 page you should see pics of the covers.
• Yes-- +, - and flat
• Yes--the 2 screws are the connection to the amp. The 4 color-coded screws are for connecting a 4-wire cable to the speaker: common and woofer, mid, tweeter. KLH supplied a pair of short cables for those who want to mount the contour box on the back of the speaker, and a long (40') cable so you can control the contour from your listening position.
• Not sure about the crossover points but that sounds right.

I have some lit that's too big to post here--watch your email.

-Kent

[ra.ra]

Thanks for sending those documents - - - I understand a little better now. And yes, I finally do see the pic of the wood enclosure. That's a rather unique device, and with that unusual 4-wire connecting cable. The Hirsch review was a little difficult to read, but it was interesting that both the review and the product instructions discussed making initial control settings while listening to FM inter-station hiss, and later making subsequent adjustments listening to familiar musical sources.

[RickB]

Were you able to do this for Robert ? Your offer was fantastic-thank you for being so humanistic.

Sincerely,

Rick

[Neal K]

On 12/22/2007 at 11:06 AM, RoyC said:

This is one of the most sensible capacitor discussions I have read in a long time (other than the "guru" part...thanks Kent :-)!

If you guys want to split the difference, you can try low value mylar caps on the tweeters (maybe even the mids) and electrolytics for high values. Many commercial speaker companies have done this.

Mylars, like electrolytics, but less so, appear to have a bit more esr than polys do, so don't feel compelled to tweak the circuit if you are not in the mood to do so. They are relatively inexpensive, and easily obtained from Madisound (Carli branded and "surplus"..the 3uf surplus caps are very good!). The main advantage of this approach is that film caps are very stable for the long term, and that degradation issues are more likely to be bothersome in the upper frequencies. Madisound also sells Bennic electrolytic caps, which have a good reputation.

Roy

Hi guys I am new here. I have been restoring, modifying, or building speakers a few years now. I discovered PE and Madisound, which are both great. In looking for information on driver sand crossover schematics I have come across some of these "Boutique" crossover sites and threads. What substances are these guys on? They talk about the aural qualities of capacitors as though they were drivers! And the crazy prices of some of these "Audiophile" capacitors is kind of nutty. i wanted to post a question: does anybody here realize that these components BLOCK or FILTER frequencies. You are not supposed to hear them! Distortion I can understand. But given that the majority of serious professional speaker and monitor designers and makes use electrolytics, does this not suggest something? Are these threads just fronts for the designers, builders and marketers of these crazy priced components? I figure that has to be it. Or there are more delusional people in the world than I thought?  

[kittidat]

Hi there, I need help, I now connect KHL 12 with woofer goodmans audiom 51 12",  Jensen rp-201as midrange and Jensen rp 103 as tweeter. Unfortunately, No mid range sound comes out. Any suggestion to fix this out?

[JKent]

Welcome kittidat

I'm not sure I understand your question. Are you using KLH Model Twelve contour boxes with those Goodmans and Jensen drivers? If so, you may have the contour boxes hooked up wrong. 

On the back of the contour box there are two terminal strips. The bottom strip has 2 terminals for the connection to the amplifier. They should be painted black and silver. If not, the left one (viewed from the back) is - and the right is 8 ohm (+).

The top strip has 4 terminal screws that should be painted Black, Red, White, Yellow. Black is - and common to all 3 drivers. Red is woofer +, White is mid +, Yellow is tweeter +.

[kittidat]

Thank . JKent

[jams]

wear can i buy a set of contour control boxess 586 486 4562 help please

 

[JKent]

Rob may have a pair for sale. I told him to check this thread.

[Amarjr]

Yes, Kent did a fantastic work on my Crossovers and I have been remiss in giving him ample recognition. IT took me a year to do about an hour's worth of work sealing the driver surrounds and re-seating them with plumber's putty before listening to them. Yes, it was very tempting but I heard it could damage the drivers if they are played and not sealed.

They are awesome. Ken is awesome! I have an open floor plan with the 12s in Living room against sidewalls of an archway facing the front of house and they fill the first floor with wonderful sound at a third volume. I specifically placed them facing away from center of house to soften the volume.

BTW: my better half loves the fit with our MCM decor

[Brutus]

I found my pair of twelves on the side of the road out for garbage. I slammed the brakes on and my wife says what are you doing. I said I got to check those speakers out. When I got my first sight I couldn't believe my eyes. Two model 12 and two contour boxes complete. So I loaded it up in my pickup and took them straight home wasn't  prepaired  for hauling speakers. Got them home and found out the speakers all worked but needed to fix the contour boxes. Ordered parts and fixed them they sound great.