New to Model Six, Looking for info on age and restoring

[twentyfourblackbirds@gmail]

Hi all,

Thank you for posting/hosting such a repository of vintage speaker information.  I'm new to the forum, looking for info on a pair of Model 6's I saved from the dump.  I'll work on some detailed photos, but I'm wondering if there is a way to age the speakers?  Apologies if this info is posted somewhere here, i tried a few searches and didn't find anything.

One is missing a tweeter, but otherwise both seem fairly intact (the connectors on back are a bit bent sine they extend beyond the case and these looked like they were thrown out to the curb (literally where i found them!) I haven't hooked them up yet (and might not until I get the tweeter replaced, but I'm really glad they such acclaimed speakers.  I grabbed them only knowing they looked like the same quality and vintage as a set of 1950's build-your-own Klipschorns I was gifted years ago.  I wouldn't say i'm a speaker buff, but i think the universe is pushing me that direction :)

 

Thanks in advance for any tips/info!

[twentyfourblackbirds@gmail]

Here's some pictures (first three are the first speaker, second three the second)

[Norman Nicolai]

Welcome to the forum!

Your speakers were probably made in the mid-60's. From what I have read the original Model 6's had the woofers epoxied into the cabinets. Your drivers are screwed into the cabinets, so they definitely date from 1964, or after. However, they were probably manufactured not long after 1964 because the rear metal plate is mounted flush to the cabinet along with a speaker terminal configuration that allows you to bypass the tweeters and use the woofers only. If I am not mistaken, some time in the mid-to-late 1960's KLH Model 6's recessed the metal plates into the cabinet for the terminals, and the tweeterless connection option was eliminated. So your speakers probably date between 1964-1968.

You will want to get a matching black enameled tweeter to match the one you have. Some Model 6's, including the set I own, have silver colored tweeters. The tweeters are the same ones that were used in the KLH 17's and 20's, and you will find both black and silver tweeters in those models depending on their dates of manufacture. The capacitors in the crossover unit will certainly need to be replaced also. KLH speakers are notorious for using incredibly cheap caps.

Not sure from the photos, but it looks like a previous owner may have coated the cloth speaker surrounds with something other than an ideal sealant. If you post again, please include a close up of the surrounds to see if that was done. Except for a few ported designs, all acoustic suspension KLH speakers need a relatively airtight seal with the cabinets to sound their best. The original surround sealant was a specialized "dope" that KLH would add to the porous surround fabric to keep them airtight. Some people used a rubberized sealant on the fabric to keep them airtight once the seal from the factory "dope" deteriorated. If your woofers were treated with something other than the real KLH stuff, the performance of the woofers may possibly be somewhat compromised. Hard to tell from your photos, but they look kind of suspicious.

Hope this helps.

 

 

 

[JKent]

Welcome 24

Good advice from Norman. Also read the Manual. The shorting strap between terminals B & C is missing. You can just make a jumper with plain wire. When you remove the speaker terminals (#8-32 machine screws) to straighten the metal plate be SURE to note the placement of 2 rubber washers on each one--one flat, one shoulder washer. These are absolutely necessary to prevent shorting of the screws against the metal plate. Stupid design.

When you look for a tweeter you can use one from a KLH Model 6, 17, 20, 30, or 33, regardless of color (black or silver).

Kent

Model Six Manual (this is for the earlier version with epoxied-in drivers but otherwise applies to yours). Another example of stupid design. Be glad you don't have those.

Comments about "stupid design" with regard to metal back plate and epoxied drivers aside, the Sixes are excellent speakers. Henry said he "got it right" with the Sixes.

http://www.classicspeakerpages.net/library/klh/klh_6_klh_model_six/klh_6_manual/

 

[twentyfourblackbirds@gmail]

On 5/30/2020 at 9:54 PM, Norman Nicolai said:

Welcome to the forum!

Your speakers were probably made in the mid-60's. From what I have read the original Model 6's had the woofers epoxied into the cabinets. Your drivers are screwed into the cabinets, so they definitely date from 1964, or after. However, they were probably manufactured not long after 1964 because the rear metal plate is mounted flush to the cabinet along with a speaker terminal configuration that allows you to bypass the tweeters and use the woofers only. If I am not mistaken, some time in the mid-to-late 1960's KLH Model 6's recessed the metal plates into the cabinet for the terminals, and the tweeterless connection option was eliminated. So your speakers probably date between 1964-1968.

You will want to get a matching black enameled tweeter to match the one you have. Some Model 6's, including the set I own, have silver colored tweeters. The tweeters are the same ones that were used in the KLH 17's and 20's, and you will find both black and silver tweeters in those models depending on their dates of manufacture. The capacitors in the crossover unit will certainly need to be replaced also. KLH speakers are notorious for using incredibly cheap caps.

Not sure from the photos, but it looks like a previous owner may have coated the cloth speaker surrounds with something other than an ideal sealant. If you post again, please include a close up of the surrounds to see if that was done. Except for a few ported designs, all acoustic suspension KLH speakers need a relatively airtight seal with the cabinets to sound their best. The original surround sealant was a specialized "dope" that KLH would add to the porous surround fabric to keep them airtight. Some people used a rubberized sealant on the fabric to keep them airtight once the seal from the factory "dope" deteriorated. If your woofers were treated with something other than the real KLH stuff, the performance of the woofers may possibly be somewhat compromised. Hard to tell from your photos, but they look kind of suspicious.

Hope this helps.

 

 

 

Yes, that is all great info, thank you!  Is there a place you'd recommend to buy the replacement tweeter (any other other components i'll need to get these working again?) I'll work on getting more pictures.  Is there any harm in unscrewing and pulling out the speakers to inspect the condition inside?  

[twentyfourblackbirds@gmail]

On 5/31/2020 at 2:30 PM, JKent said:

Welcome 24

Good advice from Norman. Also read the Manual. The shorting strap between terminals B & C is missing. You can just make a jumper with plain wire. When you remove the speaker terminals (#8-32 machine screws) to straighten the metal plate be SURE to note the placement of 2 rubber washers on each one--one flat, one shoulder washer. These are absolutely necessary to prevent shorting of the screws against the metal plate. Stupid design.

When you look for a tweeter you can use one from a KLH Model 6, 17, 20, 30, or 33, regardless of color (black or silver).

Kent

Model Six Manual (this is for the earlier version with epoxied-in drivers but otherwise applies to yours). Another example of stupid design. Be glad you don't have those.

Comments about "stupid design" with regard to metal back plate and epoxied drivers aside, the Sixes are excellent speakers. Henry said he "got it right" with the Sixes.

http://www.classicspeakerpages.net/library/klh/klh_6_klh_model_six/klh_6_manual/

 

Many thanks, I Will be on the look out for more used KLH's to possibly cannibalize for parts   I'll give the manual a read as well.  I'll try to get some more pics soon (apologies in advance for slow replies---running my small chocolate company right now is tricky with very limited staff).  Thanks for the feed back so far JKent and Norman Nicolai

[JKent]

7 hours ago, twentyfourblackbirds@gmail said:

Yes, that is all great info, thank you!  Is there a place you'd recommend to buy the replacement tweeter (any other other components i'll need to get these working again?) I'll work on getting more pictures.  Is there any harm in unscrewing and pulling out the speakers to inspect the condition inside?  

Ebay for tweeter (KLH Model 6, 17, 20, 30, or 33). You can also put a free "wanted" listing in the For Sale section here. For the capacitors either PartsExpress, Madisound or Erseudio. You'll need two 2uF and one 8uF cap per speaker. Here's a good thread on restoring a pair of KLH Seventeens. The crossovers are the same as the Sixes https://www.audiokarma.org/forums/index.php?threads/renovation-of-my-klh-17s-is-complete-long.102176/

If you want grilles you'll have to make frames. Very nice linen in 18 count "lambswool" color from online seller 123 Stitch or, much less expensive and not bad, 28 count Irish Linen (made in Poland) from Michael's in "tea" color. 40% off coupons readily available. And if you want KLH badges I have reproductions--PM me.

Kent