new to this -- AR3a's from dump to living room

[Carlspeak]

P.E. sells self-adhesive closed cell foam tape in 3/8 and 1/2 inch wide by 50 ft lengths in the $4 - 5 range. Good recovery on the foam. I use it sometimes when doing experiments where I adhere it to the frame of a woofer I'm going to remove and put back numerous times. p/n 260-540 & 260-542.

They also sell 1/4 inch wide by 36 inch black caulking http://www.parts-express.com/pe/showdetl.c...tnumber=269-300

for less than $1. Two coils of this stuff will do 2 twelve inch woofers. It will probably do a good job on ducts as well.

[genek]

P.E. sells self-adhesive closed cell foam tape in 3/8 and 1/2 inch wide by 50 ft lengths in the $4 - 5 range. Good recovery on the foam. I use it sometimes when doing experiments where I adhere it to the frame of a woofer I'm going to remove and put back numerous times. p/n 260-540 & 260-542.

They also sell 1/4 inch wide by 36 inch black caulking http://www.parts-express.com/pe/showdetl.c...tnumber=269-300

for less than $1. Two coils of this stuff will do 2 twelve inch woofers. It will probably do a good job on ducts as well.

I get similar stuff from my local Ace Hardware store. Price is a bit higher than PE, but no shipping cost. Of course, if you're already ordering something from PE, it's a no-brainer, add it on.

I do suspect, though, that the added "give" of foam weatherstrip might not have the same longterm vibration characteristics as a harder gasket (caulk or thinner foam). Probably not an issue for mids and tweets, but if using it longterm on a woofer it would probably be a good idea to check the screws once in a while to make sure they aren't loosening up.

[RoyC]

P.E. sells self-adhesive closed cell foam tape in 3/8 and 1/2 inch wide by 50 ft lengths in the $4 - 5 range. Good recovery on the foam. I use it sometimes when doing experiments where I adhere it to the frame of a woofer I'm going to remove and put back numerous times. p/n 260-540 & 260-542.

They also sell 1/4 inch wide by 36 inch black caulking http://www.parts-express.com/pe/showdetl.c...tnumber=269-300

for less than $1. Two coils of this stuff will do 2 twelve inch woofers. It will probably do a good job on ducts as well.

I agree with Carl. PE's high density foam and black caulk strips are both excellent and unique. It should be noted that most, and eventually all, AR speakers after 1970/71 used foam gaskets, which have held up very well. The dense foam tape sold by PE has the ability to expand into voids, and is usually as effective as putty...especially on later, smoother cabinet cutouts. The foam is great for frequent removal of woofers while working on projects.

Roy

[Mexicomike]

I would never argue with the fact that the duct seal is a LOT harder to deal with if you are going to be doing adjusting/modding, etc. In my case, the next time any drivers will be coming out of my 3As/LSTs will be by someone else after I've gone on to a better (or possibly, worse) place! Statistically, that means they won't have to last as long as they did the first time!

[genek]

I would never argue with the fact that the duct seal is a LOT harder to deal with if you are going to be doing adjusting/modding, etc. In my case, the next time any drivers will be coming out of my 3As/LSTs will be by someone else after I've gone on to a better (or possibly, worse) place! Statistically, that means they won't have to last as long as they did the first time!

You hope.

Seriously, though, replacing a blown 35 year old driver with a NOS 25 year old driver means that there's a good chance you'll be prying the replacement out in 15 years. The materials deteriorate even if not in use. Which is why I'm tinkering around with potential new replacements in addition to scouring the auction sites for originals. I'm planning on still being around in 15 years.

[JKent]

Here's another option: There is a 3a "factory replacement" woofer on ebay Item number: 270293988972 that may be a good match for your foam surround woofer. Maybe pull the cloth surround woofer, sell it, and put the $$ toward the replacement and the refoam on the other one. Just a thought.....

Kent

PS I have no knowledge of or connection with that ebay seller

[dick]

Thanks for the tip, Kent. I looked up the speaker and learned a bit about eBay. I'll not pursue that speaker, however. I'm currently working with Carl on a speaker solution and hopefully something will gel within the week. While I'm still personally in the basement on the entire speaker learning curve, I've absorbed the idea that the older cloth surround woofers provide better sound. I'm working toward that sort of solution.

Will look up on Google today such things as "crossovers, " "capacitors," "induction coils." While I'll never figure out a Wheatstone bridge, I thought I might just have a chance of getting a handle on the way juice flows from amp to my ear.

[JKent]

Will look up on Google today such things as "crossovers, " "capacitors," "induction coils." While I'll never figure out a Wheatstone bridge, I thought I might just have a chance of getting a handle on the way juice flows from amp to my ear.

fwiw--I joined the CSP forum 2 years ago while trying to restore my old AR4x speakers and had no clue whatsoever about any of this stuff, beyond having built a couple of simple dynaco and Hafler kits back in the day. My point is; you will find a HUGE amount of information and help from the dedicated enthusiasts here. Replacing caps (capacitors) seemed like rocket science to me at first, but it's really very simple and, on 40 year old speakers, very necessary. Refer often to the Manual and ask questions here. You will soon be hooked (or maybe you are already )

Good luck

Kent

[dick]

Kent,

Hook set solidly in jawbone, fish (me) trashing, running deep. I found an instructional website that brought me up a bit from the basement floor of speakerdom: http://electronics.howstuffworks.com/speaker8.htm. Overview kind of narrative that sketched out the lay of the land re: crossovers and speaker coils and such.

If one ever needs it, BTW, I did find Permatex 80062 (for careful coating of speaker cloth surrounds--see 3a restoration guide) at a local NAPA auto parts store. NAPA distributes under their own label: Part #765-1221. The clerk cross-referenced numbers with Permatex, the supplier to NAPA (they share logos on the can). It was, he said, 80062. I'd suggest getting one's clerk to also cross-reference.

[oldguide]

When I rebuilt my LSTs they also had very poor woofer return - popped right back. Some of the problem in their case was missing screws in the crossover panel but even with that corrected they still returned rather quickly. Turned out the foam gasket for the woofers wasn't sealing very well. I replaced it with the duct seal "putty" as was used on my 3As and that did the trick. Don't know if all 3As used duct seal or if later ones used foam gaskets but I recommend you ditch the foam gaskets if you have them and use new seal for all the woofers and any other drivers that are removed. I wouldn't try to reuse the old sealant even if present - clean it all off and use new.

Lowes carries the stuff in 1lb bars in the department where they have ductwork for heating/ac. It's simply called "DUCT SEAL" and the package looks just like the 1lb blocks of C4 we used when I had the opportunity to visit an exotic southeast Asian country some years ago...

Mike and I still agree, although we may be talking about two different types of duct seal. The type I am referring to is used for electrical installations. As for duct seal vs foam, I am a newbie here, but to my sense is that foam is always going to deteriorate and slowly lose its seal. Duct seal is designed not to do that. The national electrical code does not allow the use of any foam, spray or otherwise to seal lines coming into a house because it does shrink and deteriorate. As for being able to pull speakers in and out, I needed to make one change after I had put the sealant on the woofer and it was not that big a deal to pull the woofer.

[Mexicomike]

It's probably the same thing. The stuff I bought at lowes looks/feels exactly like the oem AR stuff. Here's a link to another site where someone posted a pic of a block of the duct seal as well as some other stuff. The package is exactly the same as what I bought.

http://www.3reef.com/forums/i-made/duct-seal-49781.html

[genek]

It's probably the same thing. The stuff I bought at lowes looks/feels exactly like the oem AR stuff. Here's a link to another site where someone posted a pic of a block of the duct seal as well as some other stuff. The package is exactly the same as what I bought.

I think the "Mor-Tite" that AR originally used was an asphalt-based product that over time managed to both harden and develop an extreme grip. By comparison, most modern mastic sealers are vinyl or acetate based, and will not harden (which, from my POV is a good thing because they won't dry out and it'll be easier to remove the drivers down the line).

The foam I'm cutting my new gasket rings from is a moisture and chemical resistant teflon foam in common use in the petroleum and aircraft industries, which is the modern equivalent of the material in the later AR foam gaskets. I only use the hardware store weatherstripping for temporary sealing where I'm swapping things out frequently. I have no idea how it would be longterm.

[oldguide]

I think the "Mor-Tite" that AR originally used was an asphalt-based product that over time managed to both harden and develop an extreme grip. By comparison, most modern mastic sealers are vinyl or acetate based, and will not harden (which, from my POV is a good thing because they won't dry out and it'll be easier to remove the drivers down the line).

The foam I'm cutting my new gasket rings from is a moisture and chemical resistant teflon foam in common use in the petroleum and aircraft industries, which is the modern equivalent of the material in the later AR foam gaskets. I only use the hardware store weatherstripping for temporary sealing where I'm swapping things out frequently. I have no idea how it would be longterm.

Mike,

I was just getting ready to post my own picture since I had to pick up some of the stuff for my AR4s. Anyway, the picture shows the right stuff. However, as I mentioned before it is in the electrical department of big box stores.

It is made by GB, who also makes Deoxit and other products needed by speaker rebuilders. Part number is: DS 110. Spew on the package says: "seals conduit openings against drafts, dust moisture and noise. Non herdening. Adheres to metal, wood, plastic, rubber and painted surfaces. Non toxic, non-staining." An online retailer adds: "Aids in vibration damping."

Not to push this one too hard, but to me where duct seal is superior to any type of foam is that it will seal any minute variations in the surface. For example, on removing the woofers from my AR3s, some of the wood finish came up with the speaker and in one case also a small chip of wood. You'd have to have a pretty good foam to seal where that chip was. Because of its flexibility duct seal will seal off even the minutest variations in the surface and the flexibility is much greater than foam.

Again. duct seal is NOT weatherstripping. The name is a bit misleading as it makes you think of heating ducts when in fact it is for electrical ducts. It is used by professional electricians to seal electrical openings and connections and is required by the national electrical code for all service entrances (the L where your wire goes from your meter into the house must be packed with it and also if you are wiring right it should be at the box where the wire enters and exits). You can easily check that out just by removing the cover of the L box. It is required to last for decades or more because no one knows if or ever someone will change their service entrance. It must be capable of holding its seal in all circumstances, hot, cold, wet, snow, accidental spills, etc.

Finally, the clincher: it's cheaper. One $3-$4 bar will do a lot of woofers.

What other seal is UL approved?

BTW it is also in the "bible," p. 19. The interesting note by the authors is that the foam sealants were introduced by AR in 1971 when they were "used to make the acoustical driver seals to smooth [my underlining] MDF baffle boards."

[genek]

Not to push this one too hard, but to me where duct seal is superior to any type of foam is that it will seal any minute variations in the surface. For example, on removing the woofers from my AR3s, some of the wood finish came up with the speaker and in one case also a small chip of wood. You'd have to have a pretty good foam to seal where that chip was. Because of its flexibility duct seal will seal off even the minutest variations in the surface and the flexibility is much greater than foam.

I guess that's how you tell us woodworkers from the audio experts. I filled and sanded all of those chips before I put the speakers back together again.

[oldguide]

I guess that's how you tell us woodworkers from the audio experts. I filled and sanded all of those chips before I put the speakers back together again.

That crack is over the line--the first time I have seen anything like this on this board. I do wood working as well as an electrical--as you may remember from my 3a restoration project and the stand models--and YES I did sand it AND repaint it--redid the entire inside as well as the outside because I wanted to have the best surface possible for a seal. That's just common sense. But the point is once you have a good surface, what sealant works the best. On this as with other things on this board (remember the long thread on 3a tweeter replacement) it appears there are differences.

I had thought this was a place where we don't make cracks about people's abilities and try to help one another, not make snide remarks.

If you don't want to use duct seal go ahead. The manual suggests either that or foam.

And no, the smile at the end does not help.

[genek]

I had thought this was a place where we don't make cracks about people's abilities and try to help one another, not make snide remarks.

I was not referring to abilities, but to the anal-retentiveness of someone (me) who would actually think of filling, sanding and sealing a part of a speaker cabinet that nobody would ever see once the speaker was reassembled to the point where it was smooth enough that a mastic sealer wouldn't produce a noticeably better seal than a gasket. I doubt that anyone here would lack the ability to do it, and exactly where did I suggest that that was the case?

[dick]

Here's an update on the dump-to-living room 3a's. They are playing! Yup. Lookin' Good! Carl fixed up a cloth surround woofer with some wizardry, ran his mysterious computer checks on it and also on my good speakers in the other cabinet, said all was looking okay, and sent me on my (very happy) way. Many thanks, Carl.

When I got home, I only done what any kid would do: I've popped the Carl Woofer into the cabinet, reused the old seal (just to check it out, right?), spread out the suspicious stuffing, and hooked the pair of speakers up to the stereo. Need to take an hour to just sit and listen. Like now.

I'm going to take someone's adive and "Go Slow." At least for now. The sound is nice. On the horizon, come snow and ice and days inside, I'll looking into the followng:

A. Weight and distribution of stuffing (netting behind woofer).

B. Those pots (do they or don't they work?) -- I feel the coils when I twist the knobs. That's good isn't it?

C. Condenser replacement.

D. Exterior fixing up.

E. Get someone with younger ears to tell me that the hi-range drivers deliver sound.

OK! Thanks to everyone for advice, comments, guidance. Greatly appreciated.

The big problem now is to not go to dump looking for more speakers.

[dick]

Well, it is all done. Thanks are due to all but especially to Roy C for great advice, guidance and a gift to make the speaker picture perfect, to Carl for a woofer trade that worked out marvelously (I'll leave it to Carl to explain his innovation if he so wishes). I've just finished my glass of wine for the day or I'd raise it high to all of you.

I've prowled that Despotic Home big box for the correct duct sealer goop, for the perfect (really!) wood refinishing goop. The linen grille was Oxicleaned (smelly, that stuff) and started to look quite perky especially with shined up badges. 2 NPE caps + 1 PP cap (tweeter) replaced some pretty heavy old caps. The pots were taken apart and steel wooled plus a finger coating of WD40. Crinoline protected the woofers from fiberglass, although as a picture shows, the one seems to have come protected. The only divergence was in the quantity of fiberglass stuffing. I went down to 26.5 oz. based on the fact that 30 oz was strangling the woofer's lower register and 28 oz. didn't look like it gave the woofer room enough to flex that air.

Two terribly minor things: 1) the pots cannot be messed up if they come apart in one's hands. They only go back together one way. I thought for a moment that I had sprung a mess on my hands when the first came apart. 2) Not knowing yes/no on the matter I plugged the 6 holes left from the 150/50 uf cap screws -- just used some of tha duct sealer.

It is music time here! From dump to living room to prized possession. Muchas gracias, many thanks. Hope the attachments come through. I'll be lurking the CSP Forum's AR discussions, after all now I know what a crossover is, what the cap and coil do! Somehow, previously, I naively thought that the wires from the amp went directly to the speakers....

Cheers, Dick

[Carlspeak]

Nice job Dick. Now you can just enjoy the music. After all, that's what it's all about!