KLH Five woofer question

[JKent]

Hi all

I just bought what appear to be a very nice pair of Fives via Craigslist. One odd thing though. One woofer was replaced. The replacement has "KLH" on the dustcap, but it is obviously newer. The surround is foam, not cloth, but it IS "reversed" like the original. The cone is gray, not brown like the original. Attached is a picture. What do you think? Is this the genuine KLH replacement for the Five's woofer or something from some other speaker? Should I be looking for an original woofer?

Thanks

Kent

[Andy]

Interesting, it may very well me something KLH had as a replacement in the 1980's ? Does it have similar cone travel when you gently push on it. Also, how does it do on a sound test ? If it produces nice sound, I'd let it be, but keep your eyes open for an early woofer...there still seems to be a good supply of woofers being offered out there.

Enjoy your Model Five's, there great speakers

Andy

[KLHSvcMgr]

Hi Kent...

The original 5 driver is the one on the right, in your picture. The original KLH replacement was part number 8811. It replaced the first replacement driver because of significant field failures. The newer 8811 had a longer throat with a better excursion. The 8811 also replaced the driver in the Model 23 as well. The original driver in the Model 23 was in-volved in a field rework procedure because several of the original 23 drivers caught fire when over driven.

Mark

[JKent]

>The original KLH replacement was part number 8811. It

>replaced the first replacement driver because of significant

>field failures. The newer 8811 had a longer throat with a

>better excursion. The 8811 also replaced the driver in the

>Model 23 as well. The original driver in the Model 23 was

>in-volved in a field rework procedure because several of the

>original 23 drivers caught fire when over driven.

>

FIRE!? OMG!

Thanks once again for your help and info Mark. So the replacement driver I have is a "better" speaker than the original? I thought maybe I should replace it with an original so I would have a matched pair, in case I decide to sell them. The original has a big round magnet, cloth surround. The replacement has a big square magnet and foam surround. If it has a longer throat and better excursion, shouldn't it sound different? (maybe I should look for a second 8811 and replace the older woofer)

Kent

[KLHSvcMgr]

Hi Kent...

I can't comment on the driver with KLH on the dust cap. This is a replacement driver from a later KLH company and I have never actually seen one.

The redesigned 8811 can be identified by a circular extrusion on the back of the magnet assembly. It was more or less over designed to insure that it would not have any possibility of failure caused in the original driver.

If I were doing the job, I would locate a modified 8811 to insure the best possible match.

Mark

[JKent]

>I can't comment on the driver with KLH on the dust cap. This

>is a replacement driver from a later KLH company and I have

>never actually seen one.

>

>The redesigned 8811 can be identified by a circular extrusion

>on the back of the magnet assembly. It was more or less over

>designed to insure that it would not have any possibility of

>failure caused in the original driver.

Always helpful Mark. btw--like your web page (Plan to finish construction? ;-) )

The "circular extrusion"--is that the piece held on by 3 bolts? I did locate a matching woofer, so I'll try to sell the other. Guess it fits the 5 (obviously) and the 23. Six? Any other models take that size speaker?

Kent

[KLHSvcMgr]

The identifying indicator is on the flat plate at the back of the magnet. The old version is flat while the newer version has a bump in the middle.

Old Version:

|---------------------------|

| |

|---------------------------|

| |

| Magnet |

Speaker Front

New Version:

|---------|

|---------| |---------|

| |

|-----------------------------|

| |

| Magnet |

Speaker Front

Sorry 'bout the crude drawing...I flunked art.

Mark

[KLHSvcMgr]

Sorry folks, the drawing didn't turn out, so I guess I can't really give a detailed diagram.

Mark

[tysontom]

>Sorry folks, the drawing didn't turn out, so I guess I can't

>really give a detailed diagram.

>

>Mark

Mark, make your AR-5 woofer drawing, then either scan it or take a small-size camera image of it and then you can post it as a jpeg attachment.

--Tom Tyson

[soundminded]

I am truely amazed to hear that the KLH model 5 had issues with fire. I'd heard about this in regared to a later model called the Baron or Little Baron which I think was a two way 10" system which looked similar in appearance to the Bose 501. Any information about that? Several friends of mine bought KLH model 5s on my recommendation. On paper it looks better than KLH model 6 including a superior woofer but for some reason, in listening, I usually thought the model 6 sounded more accurate having less mid bass peak or muddiness? Any thoughts about that? It's been a very long time since I heard a pair.

[JKent]

Funny you mention muddiness. When I listened to these Fives I thought they were overly bright. I compared them to my AR2ax's, which were MUCH mellower (maybe a little too much bass, therefore not really accurate) and a pair of Allison Sixes, which sounded GREAT--full bass, detailed mids and highs. The ARs were up against the wall, which would reinforce the bass, while the KLHs were well out into the room (but so were the Allisons, which are meant to be against the wall).

Right now the Fives are apart. I bought one new (original) woofer so I would have a perfectly matched pair,and I'll be eager to do some critical listening when I get them back together.

Any ideas about why these sound so bright/harsh? Could it be the xover (hope not)? They sounded similar to my KLH 20s. I also have a pair of 33s that I have not yet compared to the Fives.

[tysontom]

>I am truely amazed to hear that the KLH model 5 had issues

>with fire. I'd heard about this in regared to a later model

>called the Baron or Little Baron which I think was a two way

>10" system which looked similar in appearance to the Bose

>501. Any information about that? Several friends of mine

>bought KLH model 5s on my recommendation. On paper it looks

>better than KLH model 6 including a superior woofer but for

>some reason, in listening, I usually thought the model 6

>sounded more accurate having less mid bass peak or muddiness?

>Any thoughts about that? It's been a very long time since I

>heard a pair.

Soundminded,

Speaker fires are not particularly rare, but the causes are usually an amplifier with extreme offset problems (some early AR Amplifiers occasionally had this bias-voltage problem), causing rail-voltage DC to pass directly into the voice coil. This was the reason for the AR Amp output fuses -- not so much to protect a speaker against overdrive -- but to protect speakers against the rare, but devastating DC voltage across the output terminals. A good friend of mine had a pair of AR-7s, driven by a malfunctioning AR Amp, catch fire (internally). The voice coils got extremely hot, of course, ceased to work, and briefly charred the fiberglass inside the sealed cabinet. The amplifier completely shut down before things got out of control, but the woofers were ruined.

--Tom Tyson

[soundminded]

>Funny you mention muddiness. When I listened to these Fives I

>thought they were overly bright. I compared them to my

>AR2ax's, which were MUCH mellower (maybe a little too much

>bass, therefore not really accurate) and a pair of Allison

>Sixes, which sounded GREAT--full bass, detailed mids and

>highs. The ARs were up against the wall, which would reinforce

>the bass, while the KLHs were well out into the room (but so

>were the Allisons, which are meant to be against the wall).

>

>Right now the Fives are apart. I bought one new (original)

>woofer so I would have a perfectly matched pair,and I'll be

>eager to do some critical listening when I get them back

>together.

>

>Any ideas about why these sound so bright/harsh? Could it be

>the xover (hope not)? They sounded similar to my KLH 20s. I

>also have a pair of 33s that I have not yet compared to the

>Fives.

The fives I heard most were in my next door neighbor's house. They were being driven by a Scott amplifier which may have been underpowered. Maybe muddy is the wrong word, perhaps a little bottom heavy might be more descriptive. Might have been the room or their positioning in the room, they were on the floor with against the wall. Might have been the switch settings on the back or his phono cartridge, who knows, it's been around 35 years since I heard them. As for your fives being too bright, one interesting thing is if you look at the schematic for the crossover, you'll see both the midrange and high frequency setting switches affect the tweeter, the midrange drivers remain unaffected. Could there be an apparant lack of bass due to an air leak through the cloth surrounds? I'm not sure I've got a definitive answer about how to check for this yet except to measure frequency response or just listen to them. I think I'd try the sealant from Orange County speaker company. Are both midrange drivers operating? Moving the speakers away from the wall reduces the loudness of the bass making the treble sound more prominent by comparison. I assume these are the original tweeters. I remember KLH model 6 sounding brighter than AR2ax. I've got a pair of AR2ax in my basement I've yet to restore. Perhaps that will be my next project. I haven't heard AR2ax in over 25 years either. Hearing old equipment for the first time in many years is like meeting an old friend for the first time all over again.

[joelongwood]

I have both the KLH 5's and 2ax's. In direct comparison, I find the KLH to be quite a bit brighter as well, with a particular emphasis in the upper midrange. However, I wouldn't term them "harsh" at all.

When switching back and forth (both driven by a Yamha CR-600), the openness and clarity of the KLH 5's, particularly on vocals, is readily apparent. Cymbals also come to the forefront on the KLH, much more so than the AR2ax. I read somewhere (Tom Tyson, maybe?) that Henry Kloss designed his speakers to grab the listener on first hearing them.......hence the brighter sound. Just a thought.

BTW, I sealed the surrounds of the KLH with a thinned silicon latex caulk/water mix when I acquired them about 2 years ago.......the bass improved dramatically.

[dynaco_dan]

Hi there;

Regarding fires in KLH speakers.

Having worked at our local stereo service center for a few years gave me the opportunity to see numerous overheating situations.

I still remember AR-4X woofers that had charred voice coil forms, absolutely toasted.

Dynaco A-25 woofers were all about 90% toasted.

Interesting though, the A-25 and all classic Dynaco speakers, Dynaco glued their power resistors and switches to a plywood sub-base and I've never seen a single char mark, yet.

AR pot's with red and black plastic shafts melted totally.

I have read nothing else in this regards to Advents or other's as well.

An AR-2 I recently purchased was tested before listing on ebay, so I was told.

When I received it the tweeter was dead.

Actually, I found that 1/2 of the Clarostat 10 ohm 4 1/2 watt pot was fried, ashes fell out of the housing when I removed the rear cover.

In retrospect, it is amazing that there has not been house fires caused by speaker fires, or maybe the cause of the fire was not investigated as thoroughly as we now know.

Who would ever think of a speaker causing a house fire?

Do I see house fire insurance cost's rising for those only with low efficiency classic speakers?

[JKent]

> Could there be an

>apparant lack of bass due to an air leak through the cloth

>surrounds? I'm not sure I've got a definitive answer about

>how to check for this yet except to measure frequency response

>or just listen to them. I think I'd try the sealant from

>Orange County speaker company.

Looked at the Orange County Speaker site and did not see a sealant for cloth surrounds, and no "contact us" (It's probably there but I missed it)> I know Mark (KLH Svc Mgr) is also asking about treatments for cloth surrounds. I seem to remember some discussion of this some time back, but my search did not turn it up.

Anyway....what is the product for treating cloth woofer surrounds?

thx

Kent

[soundminded]

>> Could there be an

>>apparant lack of bass due to an air leak through the

>cloth

>>surrounds? I'm not sure I've got a definitive answer

>about

>>how to check for this yet except to measure frequency

>response

>>or just listen to them. I think I'd try the sealant from

>>Orange County speaker company.

>

>Looked at the Orange County Speaker site and did not see a

>sealant for cloth surrounds, and no "contact us"

>(It's probably there but I missed it)> I know Mark (KLH Svc

>Mgr) is also asking about treatments for cloth surrounds. I

>seem to remember some discussion of this some time back, but

>my search did not turn it up.

>Anyway....what is the product for treating cloth woofer

>surrounds?

>thx

>Kent

Orange County Speaker Inc 800-897-8373 714-554-8520 12141 Mariners Way, Graden Grove Ca 92843 www.SpeakerRepair.com product XL49 (sealant)

I think the product was originally MEK based but the later version is water based. You could call them, I think it's very cheap about 5 or 10 dollars a bottle which should handle a pair of 12" woofers.

[KLHSvcMgr]

The issue with the recall was primarily failures in the 23. The 5 and the initial runs of the Baron series both used the original C00134 ,in house manufactured, driver. The 5's and the Baron series were added to the list as a retrofit when any were received by our service stations. The normal run of the Baron series used a woofer with a blue, foam skiver, which was outsourced from Peerless, another Eastern Air Devices Company. The original C00134's were built, in house, using a wood fibre based material. The 8811's had a different composition cone.

In the 23's, the initial problem was caused by the coil form bottoming out and deforming holding it in place. The wires from the outboard connector to the speaker coil wires were riveted to the cone and then crimped. When the coil froze, the connection at the riveted connections would overheat and cause the cone to ignite and then the grill cloth. As I recall, we had two cases of actual fire in the environment that the 23's were used in.

In the 881, the distance of the throat was increased, thereby elimining the bottoming out issue. The replacement 8811 did not use rivets and could be identified by a bubble type addition to the backside of the magnet. I have a picture, someplace of the two showing the differences, which I will attempt to locate.

Mark

[soundminded]

I must say I found it somewhat surprising. My experience with large manufacturers in the US is that they want to perform both non destructive and destructive tests on their products to thoroughly examine all likely failure modes. This helps design them out of the product and avoid field failures which can have serious consequences for future sales. If they don't perform them in house, they send them out to independent laboratories such as US Testing Labs. Home high fidelity loudspeakers I think do not normally need or carry UL listings as they are installed in power limited circuits under 50 volts. However, people invariably do amazingly stupid things...such as cutting a 120 volt extension cord up to make an inexpensive means to connect and disconnect them and then one day, someone inadvertently plugs one into a wall outlet. Not only is the risk of fire itself important but the nature of any toxic fumes evolved from the product as the result of the fire is also of concern. This should be especially true of older electronic equipment which may have used PCB capacitors. Among the biproducts of such fires are dioxanes and difurans. Fires involving PVC can also have deadly consequences.

[Guest matty g]

>

>Who would ever think of a speaker causing a house fire?

>

>Do I see house fire insurance cost's rising for those only

>with low efficiency classic speakers?

Hi -

Yes, believe it or not, house fires have started from overheated speakers. That very thing happened to a friend of mine about 3 years ago. He was (over) driving a pair of Tannoy studio monitors with a Haffler amp while everyone was enjoying a nice day on the patio out back. Fortunatley, someone went in the house for a beer and smelled the burning plastic coming from the back room. The room was on the verge of becoming fully involved - flames were approaching the ceiling - but he was able to put it out without the fire department having to be called. Five more minutes and it would have been quite a different story. He only lost the Tannoys, a pair of Community PA speakers (that's what the Tannoys were sitting on) and suffered some smoke damage. In conclusion - it does indeed happen, and not just to vintage stuff, either.

Matt

[JKent]

OK. Back to my original questions:

1. What is this speaker from?

2. Why do the fives sound so harsh? The woofer surrounds are fine. I set up a blind listening test for my wife. We compared the Fives with my AR2ax's, a pair of AR 7s, and a pair of KLH 20s. She liked the AR2ax sound best but we both agreed the Fives lacked warmth. They were just too bright/harsh. Just thought of something. Maybe I should WATCH the woofers and see if anything is happening. I sure don't HEAR 10" woofers!

[day67]

Hi, Kent. Regarding the 5's, it's interesting that you have been able to make some real comparisons. I recently picked up a pair of 5's that,unknown to me at the time, had the woofers replaced with a pair from the model 6 as the speakers are the same diameter and pattern. Swapped them out for the originals. At the same time had the x overs recapped. Got everything back together -- the woofers leaked badly due to the surrounds and they sounded muddy and weak. I did get the white latex sealer (dries clear)from Orange County, diluted it about 70/30 with water. Made a huge difference with the base being tighter and more pronounced. But, they are bright as you say. In fact, the tweeters are so forward that I had a difficult time hearing the mid ranges. I had a spare model 5 of the newer type xover, not recapped and that was also rather bright. Same issue with the mids.

Thing is, the clarity is so much improved and as I have no other frame of reference or opportunity for comparison, these sound great! I guess it's all relative......yes I know what will happen when I listen to a very good pair of AR's and my frame of reference expands. Anyway, as a KLH fan I hope you enjoy them, Dan

[JKent]

Thanks Dan. Maybe I'll try coating the surrounds. I have some of the wite water-based stuff from M_Sound so it's worth a try.

So many speakers, so little time. Also fiddling with a bad speaker in an Advent 400 radio (sounds thin), some great little speakers from a KLH Eight and Thirteen (stained grill cloth) and my pile of KLH, AR and JansZen (one pair) speakers in various stages of restoration. I think I have about 7 or 8 of the Advent 400s--2 dead, 1 tinny, 4 good. Plan to sell some stuff off next month, including KLH Eight and Twenty One radios, Eighteen tuner (to make room for more!) It's an obsession.

Kent