AR Cloth Surround Sealant?
- Thread starter Kevin64
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Kevin,
Although AR woofers seldom need much in the way of re-sealing, the sealant sold by Vintage AR will not negatively affect compliance. One or two light coats will be fine. The toluene in the product may also serve to rejuvenate the old sealant somewhat.
Roy
drknstrmyknight
Addicted Member
I used it and was very happy, if the cabinet is not sealed the sound goes downhill mighty fast.
Thank you for the advice, I will go ahead and give them a coat or two.
I found these that had been sitting in a garage for years. Did not know anything about them, except they looked vintage. Sent a good friend a couple of photos, he replied "Buy Them", so I did. $20.00 for the pair!
At his house we did a quick external clean up and put the power to them. What a disappointment. Did some research on the web and discovered great reviews and decent value.
Thanks to the AK community answering questions for this project. The most important was my first post "Restore or Sell" and the overwhelming response to restore them. That started the process of taking them apart and looking inside where no man has been since 1966 (stamped on the woofers) and that itchy rock wool (which I did reuse). Now with new caps, controls and refinished cabinets they sound amazing!
Thanks again to all the advice from AK members.
I found these that had been sitting in a garage for years. Did not know anything about them, except they looked vintage. Sent a good friend a couple of photos, he replied "Buy Them", so I did. $20.00 for the pair!
At his house we did a quick external clean up and put the power to them. What a disappointment. Did some research on the web and discovered great reviews and decent value.
Thanks to the AK community answering questions for this project. The most important was my first post "Restore or Sell" and the overwhelming response to restore them. That started the process of taking them apart and looking inside where no man has been since 1966 (stamped on the woofers) and that itchy rock wool (which I did reuse). Now with new caps, controls and refinished cabinets they sound amazing!
Thanks again to all the advice from AK members.
gbroot
Super Member
The AR2ax is on my want list. But I most likely will have to make an ebay purchase to get them, so the price has got to be low in order to pay shipping. Amazing what new caps and a coat of surround sealant will do on the AR's & KLH's. On my first set of KLH 23's I just recapped them initially. Not too exciting results, kinda take it or leave it. It wasn't until I resealed the surrounds that I learned what all the hub bub was about on the 23's. They were a totally different speaker. Enjoy the AR's!
The AR-2ax was a straight forward acoustic suspension design requiring a sealed cabinet and a very compliant woofer. Much can be learned here:
http://www.classicspeakerpages.net/
Only some versions of the AR-4x were aperiodic in design.
Roy
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jsixis
Nothing sounds better
I agree, my Hartke 4-10 bass cabinet one could see right through the surrounds the day I bought it brand new.
I've seen/heard other cabs that people "sealed them properly"
It doesn't sound as good.
They are not at all different animals...just a matter of degree.
With the exception of the AR-4x, AR models of that era did not use the surrounds for "breathability". Acoustic suspension designs almost always have adequate leakage. It is the reason why the "slow woofer return" push test works to test the seal (as described in Edgar Villchur's patent). The rear label on AR speakers of that era warned of breaking the "acoustic" seal. It is the reason these woofers must be very compliant (very low Fs).
Roy
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woodj
Super Member
RoyC is correct in that breathability was not provided exclusively by the surrounds in that era). Much was achieved through the porous nature of the of the cone material. Leaky cabinets/driver installs were however a no-no. The early Heathkit AR Speaker kits had stethoscope included in the kit to check for cabinet leaks after assembly.
But we have digressed from the question about doping the outer cone supports (surrounds). My friend bought a pair of AR kits through Allied Electronics back in 68. These proportedly had high threadcount tight weave silk surrounds which were not (and did not entertain) doping (stethoscope included).
Therein lies my caution about doping.
But we have digressed from the question about doping the outer cone supports (surrounds). My friend bought a pair of AR kits through Allied Electronics back in 68. These proportedly had high threadcount tight weave silk surrounds which were not (and did not entertain) doping (stethoscope included).
Therein lies my caution about doping.
They sent a stethoscope with the kit? That is a method to make sure there are NO cabinet leaks.
I have no idea what kit your friend received, but NO original AR cloth surround of the 60's into the early 70's (when foam arrived) was not treated with a butyl or butyl/latex compound. This has been discussed and documented at length in the Classic Speaker Pages forum. The information was provided by Tom Tyson, AR historian, and personal friend of E Villchur, as well as Roy Allison himself (designer of these AR models). This information is the basis upon which Vintage AR's sealant was developed.
Below is a photo of an original, untreated AR surround given to me by Tom Tyson from the mid-60's AR factory. It was a reject, as it was improperly cut, but it is very light and porous. The surrounds were treated after installation.
Roy
Attachments
Interesting...That was very early in the game. Perhaps it was intended to be airtight without treatment. The stethoscope would have been used to verify an airtight seal, but would not be able to discern a specific degree of breathability.
Whatever was going on in the kits of 1959, I have never seen an AR-2/2a/2ax series speaker without treatment on the cloth surround. The only change was the addition of lampblack to color it somewhere down the line.
At this point the greatest threat to AR (and KLH) woofers related to re-sealing is slathering something on that stiffens and decreases compliance, which will compromise the type of bass response these acoustic suspension speakers are known for....so, possibly for different reasons, we do agree on prudence in the matter.
Roy
woodj
Super Member
RoyC, I whole heartedly agree. It is unfortunate that in many instances, the laws of science (mostly physics) are arbitrarily applied not considering the constraints of living in a living/breathing earthly enviornment. Perfect acoustic suspension would possibly achievable under perfect conditions. As long as the outer edges and centers of the cones need to be held on the proper axis, trade offs will be necessary.
My (same as you just posted) original post was to have the OP do as much research as possible before sloshing stuff (even the new AR dope) on the surrounds because somebody somewhere said that was what to do.
Enjoyed your input. It is well regarded and informative.
Still looking for a pair of 2's along the roadside since they are old (junk? - unlikely)
John
My (same as you just posted) original post was to have the OP do as much research as possible before sloshing stuff (even the new AR dope) on the surrounds because somebody somewhere said that was what to do.
Enjoyed your input. It is well regarded and informative.
Still looking for a pair of 2's along the roadside since they are old (junk? - unlikely)
John
Kevin,
Are you saying you don't know what part of the woofer the surround is, or how to apply the sealant to the surround? I believe the sealant box includes a small brush and instructions.
Roy
GD70
Lunatic Member
Apply it to the fabric. If a little goes past the edges, it's fine. The factory applications were pretty sloppy.
Here's a pic of 3 KLH's with the sealer on the surrounds, and my AR 4x woofer surround resealed. The KLH's have two coats applied, the AR on very light coat. It really helped the bass response.
Here's a pic of 3 KLH's with the sealer on the surrounds, and my AR 4x woofer surround resealed. The KLH's have two coats applied, the AR on very light coat. It really helped the bass response.
