KLH Five vs Twelve

[dynaco_dan]

Hi there;

I was just reading a KLH brochure that was posted here a while ago by a member.

It list's the KLH Nine, Six, Seventeen, Five, Twelve, etc.

What I found interesting was, the Twelve has a 1 3/4" tweeter and the Five has a 1 5/8" tweeter listed.

They went on to say, the Five, was very much like the Twelve, but with a little more mid-bass, in case it is not on the floor, and a little less power handling capability.

The Five has 2 - 3 position switches covering, 2,500 - 7,000 and 7,000 - 20,000 cps.

The Twelve has 4 - 3 position switches in it's, remote "Contour" control box, covering 300 - 800, 800 - 2,500, 2,500 - 7,000 and 7,000 - 20,000 cps.

The mids in both speakers, as I understand it, are supposedly wired in series.

Being 8 ohm systems does that mean that these mids are 4 ohms each?

The Five, and moreso the Twelve's crossover, maybe has a few secrets inside to reveal yet, perhaps?

I feel that the external crossover of the Twelve, makes for very easy individual driver fusing opportunities, fast and slow blow types.

Now we should research what value fuses to use.

[dynaco_dan]

Hi again;

I was too slow getting back to the previous write-up. Darn

I went on to suggest a Cooper-Bussmann Fusetron/Littlefuse FNM/FLM 8/10 amp slow blow fuse just for the woofers.

An alternative might be, a 2 amp fast blow fuse, pending further investigation.

For the single tweeter, I feel that a 1 amp fast blow should be safe, yet allow sufficient energy to pass to allow decent volume levels.

For the 2 mids, I feel that perhaps 1 1/2 amp fast blow fuse should allow good peaks to pass without needlessly blowing.

Perhaps a member, in the future, will investigate the validity of these or other fuse values that owners can use.

As always, it is prudent to always have spare fuses on hand.

One can always use smaller fuse values, not larger, not just yet, at least.

[dynaco_dan]

Hi again;

>

>I went on to suggest a Cooper-Bussmann Fusetron/Littlefuse

>FNM/FLM 8/10 amp slow blow fuse just for the woofers.

I erred with this suggested size of fuse.

I was thinking of the AR-2AX speaker and suggested the AR-5 fuse instead.

I would now suggest, the FNM/FLM 6/10 amp slow blow fuse, which is the same fuse as used for the AR-2AX series speaker system, for starters.

An alternative still might be, a 2 amp fast blow fuse, pending

further investigation.

>

>

>Perhaps a member, in the future, will investigate the validity

>of these or other fuse values that owners can use.

>

>As always, it is prudent to always have spare fuses on hand.

>

>One can always use smaller fuse values, not larger, not just

>yet, at least.

[JKent]

Hi Vern

The subject of this thread caught my interest, since I am currently restoring bot a pair of Fives and a pair of Twelves. One Five had an incorrect woofer, so I replaced that. Have not touched the x-over. The Twelves had some bad resistors and ??. I have rebuilt one x-over with all new caps and resistors and it sounds great. Now on to the other. When finished I'll want to do some A/B comparison of the sound. I may end up rebuilding the Five x-overs if they do not sound as good as the Twelves.

Have to admit I have never fused any speakers. I know you advocate the practice, but I don'tt drive my amp to clipping and have never blown a speaker. You must be a heavy metal freak! ;-)

Kent

[dynaco_dan]

Hi Kent;

>The subject of this thread caught my interest, since I am

>currently restoring bot a pair of Fives and a pair of Twelves.

>One Five had an incorrect woofer, so I replaced that.

When you say incorrect woofer, what exactly are you saying?

Non-KLH woofer or from a different model KLH speaker?

Could you please expand on that comment, Kent?

Have not

>touched the x-over. The Twelves had some bad resistors and ??.

>I have rebuilt one x-over with all new caps and resistors and

>it sounds great.

There is a few w-w power sandcast resistors in the remote console boxes, did all or some of these fail?

Now on to the other. When finished I'll want

>to do some A/B comparison of the sound. I may end up

>rebuilding the Five x-overs if they do not sound as good as

>the Twelves.

I would love to read your commentary, Kent.

Hi Kent;

>Have to admit I have never fused any speakers. I know you

>advocate the practice, but I don'tt drive my amp to clipping

>and have never blown a speaker.

You must be a heavy metal

>freak! ;-)

I used to listen to loud music, BS&T's, CCR, Chicago, etc, back in the '60's and early '70's, yes.

My harping about fuses is so you and my hoping everyone that reads this will not have, hopefully, a burnt/blown driver, as I have seen hundreds of times in my experience.

In my own home stereo system, I have blown fuses, only a few mind you, mostly when I was using 1 amp fast blow fuses in an open fuseholder.

I installed and wore a seatbelt in my first old beater vehicle, long before they were mandatory here and I rarely ever forgot to do it up.

For those of you who have had a ticket for not wearing a seatbelt when in a vehicle, you may curse the police officer for the ticket.

The police officer may give you a lecture about it, or not, he will be thinking of those vehicle accidents that he has seen or heard of, where a seatbelt may have prevented a serious tragedy.

Life experiences.

I've never ever listened to Heavy Metal music, and I have never blown out any driver, ever.

Even before I started fusing my stereo system's, 30+ years ago.

I have written a number of times regarding my AR/Dynaco warantee depot experiences with, blown or toasted woofers mostly.

During that time period, 1970 - 1974 +/-, we can assume drugs, pot, high rock music levels and clipping amplifiers, etc.

I'm talking about the speaker's owner, not me. LOL

As I have read much too often from our site writers who have lost one or more drivers due to accident, error, defective amplifiers, clipping, excess cafeine, pulling cables, stepping on cables, dropping tonearm, or ?

In a perfect world we would not ever need speaker or amplifier fuses.

AR, for one manufacturer, great, wrote about why we should use fuses and unfortunately only recommended a slow blow and not also a suitable fast blow fuse, to protect from most all faults.

I would think that anyone who owns a classic speaker, or not, who's original drivers are as scarce as hen's teeth, would not consider not buying fuses.

At about $1.00 each for the open fuseholder and 3 for $2.00 fast blow fuses to protect that wonderful speaker system.

Or another way is bite the bullet and buy the larger Buss open style fuseholder, not chassis style, and Buss or Littlefuse FNM/FLM slow blow fuse's at the rated speaker amperage rating or even de-rated by a fraction.

A tweeter cost's at least $10.00 - $60.00 each used.

The KLH Twelve comes to mind as the only opportunity, a great opportunity at that, to fuse each driver section, woofer, mids, and tweeters with an appropriately rated fuse.

I am looking forward to your future write-ups, Kent on your speaker upgradings.

If you still choose to not fuse, I will not lecture you for that.

If you come back another day and say that you blew a driver, I am not going to say, "I told you so".

I may think it though. LOL LOL

[JKent]

Hi Vern

I’d be interested to know how to go about fusing the Twelves as you describe.

The incorrect woofer was a genuine KLH, but a later model and I subsequently discovered the foam surround was shot. That speaker has since gone in the trash. The saga of my Five woofers was in this thread:

http://www.classicspeakerpages.net/dc/dcbo...g_id=1115&page=

As for the resistors, I could not say whether they all failed. The Twelves in question are the ones you commented on in a recent thread: http://www.classicspeakerpages.net/dc/dcbo...g_id=1227&page=

They were a GREAT bargain—included a nice KLH 18 and a speaker selector switch, all for $100. But when I got the speakers home they sounded TERRIBLE—very tubby. I tested each driver by connecting directly from a KLH 21 radio to each driver, bypassing the outboard x-overs. The drivers were all fine, so I decided to just rebuild the x-overs. I had no way of testing the caps, but I did use a DMM on some of the resistors and found a few that were bad. Not being technically proficient, I just made a list of the resistors and caps and ordered all new ones from Parts Express. One thing I later learned was that some of the “dual” caps that I replaced with 2 new conventional caps were actually joined to the same posts. In other words, instead of replacing a dual 4uF cap with two new 4uF caps I could have used just one 8uF. Oh well. Attached are before & after pics of one x-over. Now onto the other.

Thanks for your comments and interest

Kent

[dynaco_dan]

Hi Kent;

I haven't done a KLH Twelve re-cap or resistor replacement, at least not yet.

My goodness, you sure have lot's of room inside the console, now.

Nice sharp photos too.

Just to re-hash the resistors again, please.

Did you find that they went up or down in value, as compared to their markings?

Do not toss the caps out, please.

As far as fusing them goes, you can easily wire an open style fast blow fuseholder for each of the tweeter and mids.

Either the same open style fuseholder for the woofer or the Buss open style for the slow blow type fuse.

I've downloaded a fast blow fuse block example and also a very well done slow blow fuse block example, which James did.

I also downloaded 2 other drawings which I feel you may find helpful.

They would be mounted on the back of the enclosure of course.

The wiring harness, 4 wires, from the amp to the console.

You need to connect 3 wires to their appropriate terminal and the common, we already know where it goes.

As an alternative you can, if using the console from your amplifier seating area, may mount the fuseholders at the amp end.

As far as fuses go, perhaps a 3/4 - 1 amp fast blow for the tweeter, perhaps 1 1/4 - 1 1/2 amp fast blow for the mids and perhaps 1 1/2 - 2 amp fast blow for the woofer.

The alternative for a FNM/FLM Buss/Littlefuse delayed action slow blow fuse with open style fuseholder might be, 6/10 - 8/10 amp for the woofer only.

The value of each of the fuses is un-tried and un-tested.

I believe they are a reasonable starting point at their lower size.

My first suggestion is that the fuses be located close to the amps, in case the speaker wires become shorted towards the speaker end of the cables.

This may not be convenient or WAF approved. LOL

I also think if you got those huge speakers into your house you already have an acceptable WAF because she has already seen them by now.

Or are you sleeping in the doghouse like the rest of us? LOL

[JKent]

>Just to re-hash the resistors again, please.

>

>Did you find that they went up or down in value, as compared

>to their markings?

>

>Do not toss the caps out, please.

In one x-over a 15 ohm resistor read 2 ohms and a 6 ohm resistor read 0.6 ohms. Resistors in the other x-over seem OK but it still sounded bad so I guess it was the caps.

Why save the old caps?

Kent

[dynaco_dan]

Hi again Kent;

I'm sure you've already given a light shot of DeoXit to the switches, if not, that would be a good idea, if they are still accessible.

[JKent]

Yes--used some De-ox-it. X-overs are complete and the speakers sound GREAT! Next step is the cosmetic restoration. I'll refinish the wood, patch a couple of chips. One KLH badge was missing, so I bought a pair on ebay. Not sure about the grille cloth. It's not pristine, but I would be hard pressed to find an exact repalcement. It's not like the AR grille cloth, as you can see in the photo. It's coarser and nubbier. It's also layered of black sheer cloth and the fiberboard it's stapled to is only 1/8". If cleaning with upholstery shampoo helps I'll probably leave the grilles.

Also in the photo: the crossover box has been refinished (looks darker). Some of the original knobs were missing, but I found some that I think look pretty good--cheapo Rat Shack knobs.

[dynaco_dan]

Hi Kent;

The cloth is called, "boucle", with the little mark above the, "e".

French, I presume.

I found it to be ugly but functional.

Because of it's large size, I am not going to attempt replacing it.

Your knob set looks original.

[JKent]

>The cloth is called, "boucle", with the little mark

>above the, "e".

>

>French, I presume.

"accent aigu" -- one of the few things I remember from high school French