KLH Cloth Surround Treatment

[Shacky]

I know this has been covered several times. Just want to check before treating my Model 6 cloth surrounds:

Is consensus to use 2 coats a day apart of Armorall?

Does it make a difference applying treatment to front or rear of cloth?

Thanks,

Shacky

[Shacky]

OK - I tried Armorall applied to both sides of cloth surround. At first it looked promising as holes appeared to fill in. After drying, however, it looks like it did when i first started - very porous and can see all the holes. I'm afraid Armorall isn't going to be enough for these.

Will any of the oils in Armorall prevent watered down latex caulk solution or aleene's fabric fusion from sticking?

[dynaco_dan]

>OK - I tried Armorall applied to both sides of cloth

>surround. At first it looked promising as holes appeared to

>fill in. After drying, however, it looks like it did when i

>first started - very porous and can see all the holes. I'm

>afraid Armorall isn't going to be enough for these.

>

>Will any of the oils in Armorall prevent watered down latex

>caulk solution or aleene's fabric fusion from sticking?

Hi there;

I personally have not done this procedure yet on any surrounds.

I do believe that I read here a few years ago that Tom Tyson suggested or commented on using Armorall for the cloth surrounds.

It was mentioned one coat and leave for 24 hours and then another coat.

I am now assuming that only the outer surround surface was coated.

I would hold off doing anything else without more comments from experienced members in doing this coating.

Maybe there is a viscosity difference now in Armorall.

Perhaps more than the mentioned two coats are required to more completely seal the cloth.

Each added coat adds weight to the cone.

[Carlspeak]

Can any of the classic speaker historians comment as to the absolute certainty that all of the pores of cloth surrounds MUST be sealed?

I'm not so sure that's the case.

Since I wasn't familiar with what the original surrounds looked like from the factory, I'm hoping someone who may have worked at one of these speakers companies will know the answer to my question.

It's all about the music

Carl

Carl's Custom Loudspeakers

[Shacky]

Carl,

Thhanks for the comments and added request for help. I had to get some new tweeters for this pair as both were blown When I purchased them. Was able to secure a "fresh" pair from Roy here at CSN. So I've been anxious to get them up and running.

Since the Armorall did not appear to be doing much in way of sealing very porous cloth I figured an adhesive would be best - especially if the Armorall contained any oils that might effet bonding of caulk mixture.

I ended up using Aleene's Stretchable Fabric glue. I put on one coat very lightly. I figured the cloth should not be completely airtight. I had replaced caps with original value Solens, installed replacement tweeters, re-sealed drivers with Moretite and let doping dry overnight. Woofer seems to have the correct delay in rebound after installing.

Cloth surrounds appear to be very flexible. And sound is excellent. This is my first pair of KLH's. Been listening to AR2AX's for some time now and have gained a taste for the AR's.

KLH 6's are more "real" in the mid's and hi's. I can definitely hear more detail and their timbral balance is superb. They don't go as deep as the 2AX's but they certainly aren't bass shy.

Looking forward to listening to the 6's for a while then comparing the AR's.

[dynaco_dan]

Hi Carl;

I just took a look at one of my KLH Five woofers.

Looking at the dusty front, I can see a crudely hand brushed on black compound.

It is sort of hit and miss as to whether it covered all of the surround surface and some of the cone or not.

It appears to be a finely patterned material, perhaps like surgical gauze, with this added hand painted black coating.

Looking into the magnet side, through the surround, at a ceiling flourescent light, I see about 75% light.

In other words, about 25% of the coverage could be considered as sealed.

This is just a single woofer that I grabbed at random.

I also just grabbed my nearest, 12.5 driver, the 4" full-range driver.

The material from the front is too smooth for me to see the hole pattern, with just my eyes.

It also has the hit and miss black coating.

Looking through from the magnet side, I see about 75% closed and about 25% of the holes open.

This is the reverse between these two drivers only.

The woofer has a much coarser material pattern, so this is what I see as normal.

It may be possible that the compound was to uniformly add weight to the surround and semi-seal it as well, rather than totally 100% coat it.

Because the hit and miss is so obvious, clearly hand done, it could not have been very precise to the overall driver performance, or would have been factory applied prior to being stamped out of the original material sheets.

It may have been reasonable to even dip the surrounds in a container, to allow then to soak the compound in, as an afterthought, prior to them being mounted on the cone/frames.

I see no indication of a lazy susan being used to apply the compound for any kind of coverage uniformity.

It appears that there was a race to do the application, with no consideration either to appearance, or complete application of the compound.

[Carlspeak]

Thanks Vern for your observations. I have a pair of KLH 5's here also and see about the same level of coverage as you did. I don't intend to try to seal them further.

When I seal the fabric surrounds on Pro drivers, a lazy susan makes the job much easier and neater.

It's all about the music

Carl

Carl's Custom Loudspeakers

[soundminded]

>I know this has been covered several times. Just want to

>check before treating my Model 6 cloth surrounds:

>

>Is consensus to use 2 coats a day apart of Armorall?

>Does it make a difference applying treatment to front or rear

>of cloth?

>

>Thanks,

>

>Shacky

The requirements are that the cloth be air tight and that the material that seals it must remain completely supple. If the material stiffens upon curing it will alter the bass significantly reducing the capability to produce deep bass. It may also create a false bass peak at a higher frequency. Any air leaks will also reduce bass output since the speaker relies on the springiness of the air trapped inside the box to restore the cone to its nominal position whether it is compressed or rarified. This is what differentiates an acoustic suspension woofer from all other types which rely on the mechanical stiffness of the suspension. KLH Model 6 was rated to respond down to 40 hz and when functioning properly will. A material I will probably use when it becomes necessary to seal my KLH model 6s is XL-49 sold by Orange County Speaker company. The last known phone number I have for them is 800-897-8373 and 714-554-8520. This material is not expensive and was apparantly designed for this purpose. Good luck.

[soundminded]

>I know this has been covered several times. Just want to

>check before treating my Model 6 cloth surrounds:

>

>Is consensus to use 2 coats a day apart of Armorall?

>Does it make a difference applying treatment to front or rear

>of cloth?

>

>Thanks,

>

>Shacky

The requirements are that the cloth be air tight and that the material that seals it must remain completely supple. If the material stiffens upon curing it will alter the bass significantly reducing the capability to produce deep bass. It may also create a false bass peak at a higher frequency. Any air leaks will also reduce bass output since the speaker relies on the springiness of the air trapped inside the box to restore the cone to its nominal position whether it is compressed or rarified. This is what differentiates an acoustic suspension woofer from all other types which rely on the mechanical stiffness of the suspension. KLH Model 6 was rated to respond down to 40 hz and when functioning properly will. A material I will probably use when it becomes necessary to seal my KLH model 6s is XL-49 sold by Orange County Speaker company. The last known phone number I have for them is 800-897-8373 and 714-554-8520. This material is not expensive and was apparantly designed for this purpose. Good luck.

[Shacky]

Thanks Soundminded! If I was more patient I would have orders the XL49. I did look at this before going forward with Aleene's. Since XL49 is a latex water based glue it actually helped me decide on using the Aleene's glue rather than latex caulk as recommended by others. I aslo felt that since I had put one coat of Armorall that might effect adhesion, a glue might work better.

I don't have any measureing equipment but can tell you these 6's sound wonderful. They don't go quite so low as the AR 2AX's I've been using. They are more accurate in mids and hi's than the 2AX's. I'm still drawn to that unique sound of the AR's even though some may not like them. The KLH's are more "real" sounding.

Here is link to the XL49 for anyone interested:

http://www.speakerrepair.com/Merchant2/mer...oduct_Code=XL49

And Aleene's:

http://www.joann.com/joann/shop/shop_zoom....5&SKUID=sku9062

[RoyC]

I seemed to have stumbled on a sealant very much like the original. I was asked to mention it here in KLH-land.

Go to the "Cloth Surrounds" thread in AR-land for more info.

Roy

[Andy]

I seemed to have stumbled on a sealant very much like the original. I was asked to mention it here in KLH-land.

Go to the "Cloth Surrounds" thread in AR-land for more info.

Roy

Something which might be worth mentioning - a few years ago the forum had a thread on this subject and the point was brought up that the speaker should not be 100% air tight because an enclosure that is totally air tight will restrict cone travel. Sort of like the old VW bug being air tight....with the with windows closed, you couldn't slam the door even if you really put your shoulder into it because of the air pressure inside.

I don't know how sealed the surrounds should be, 95%, 98% or maybe it is in fact 100% ? Of course a porus surround is bad and reduces funtion as noted above. Acoustic suspension does need air pressure to control cone travel, but it makes sense that at some point it would restrict the speakers function.

There's a chance I'm totaly wrong about this, but somewhere there must be some factory data on sealing surrounds. I remember the thread on this forum covering this topic a few years back was a long one with lots of info, but I couldn't find it when doing a search. ?

Andy

[RoyC]

Hi Andy,

Actually that came up in the same AR thread, so I'll refer you to that location rather than re-typing. You are correct, as the Villchur patent document filed for the AR woofer clearly states some air leakage is desirable. Old stiffened sealant, new, less compliant sealant, or too much sealant, can all compromise the compliance of the woofer suspension. Too much leakage however will compromise the necessary air pressure ("elastic restoring force") in the cabinet, which is necessary for acoustic suspension speakers like KLH, AR, etc, to perform properly.

I came to the conclusion that all water based white glues and "treatments" do more harm than good. The Permatex stuff appears to be excellent IF it is determined that a given woofer requires re-sealing.

Roy