New VS Old Woofer

[Guest speedracer]

I can open up the 2 speakers and look to see if they are wired the same, as far as "imputs term. though inductors etc." not a clue what all that means.

They are wired the same, red goes to a terminal with a copper wire which is part of a "spool" just above it. All the blues (3) are together at a terminal just above one of the "pots" i'm guessing. The problem woofer cabinet has more stuffing in it (aftermarket quilt batting?)

[johnieo]

They are wired the same, red goes to a terminal with a copper wire which is part of a "spool" just above it. All the blues (3) are together at a terminal just above one of the "pots" i'm guessing. The problem woofer cabinet has more stuffing in it (aftermarket quilt batting?)

Speedracer:

trash the quilt batting, that is the remaining piece of the missing bass. Please replace the batting with 20 ounces of yellow fiberglass. You should be able to purchase two 11-ounce packages at Home Depot - they are called "hobby pack" or some such name, no paper insulation. This will restore the bass in the second speaker. If you have fiberglass available, peel it from the paper and weight it. Please use rubber gloves, a dust mask and work outside if possible.

Cheers,

John O'Hanlon

[Guest speedracer]

Speedracer:

trash the quilt batting, that is the remaining piece of the missing bass. Please replace the batting with 20 ounces of yellow fiberglass. You should be able to purchase two 11-ounce packages at Home Depot - they are called "hobby pack" or some such name, no paper insulation. This will restore the bass in the second speaker. If you have fiberglass available, peel it from the paper and weight it. Please use rubber gloves, a dust mask and work outside if possible.

Cheers,

John O'Hanlon

It seems "whoever" overpacked this cabinet with the quilting, the other looked about 1/2 full ( with speaker laying on it's back) so this seemed OK, I just "fluffed' them both alittle. AND the Blue wire broke off just past the solder, so that also probably was part of the "lack of bottom". I noticed one of the tweeters is failing, what's the best way to re-connect those teeny-tiny wires ?

[johnieo]

It seems "whoever" overpacked this cabinet with the quilting, the other looked about 1/2 full ( with speaker laying on it's back) so this seemed OK, I just "fluffed' them both alittle. AND the Blue wire broke off just past the solder, so that also probably was part of the "lack of bottom". I noticed one of the tweeters is failing, what's the best way to re-connect those teeny-tiny wires ?

Speedracer: You should have 20 ounces of fiberglass in each cabinet.

Two issues:

do you have fiberglass or "mattress padding?"

how much is currently in each cabinet?

If not fiberglass, remove what is inside as its weight and pedegree are unknown- before scrapping, find out what what was there when you got them. If you do not have a scale, put the material from each cabinet -- perhaps two plastic grocery bags per cabinet and tie the tops so none can escape, label the bags as to their original cabinet. then weigh each one.

Best to remove all and start from scratch to ensure you KNOW what you have. Assume nothing! If no scale take the tied bags to the PO and weight them on the lobby scale - subtract weight of an extra empty bag.

The blue wire that broke near the solder has to be resoldered- too short for a wire nut. How to fix the teeny wires depends on if they are copper or aluminum. If aluminum don't solder but fix with a crimp connection. I can send you a few to tinker with will get your po address off line.

Cheers,

John

[Guest treblehit]

It seems "whoever" overpacked this cabinet with the quilting, the other looked about 1/2 full ( with speaker laying on it's back) so this seemed OK, I just "fluffed' them both alittle. AND the Blue wire broke off just past the solder, so that also probably was part of the "lack of bottom".

Do as John says. With those woofers; 20 ounces of fiberglass in each cabinet. We've fooled with this endlessly. You can fool with it endlessly, too, or you can put 20 ounces of fiberglass in each cabinet (which is what you will end-up doing in the end) and be done with it.

I noticed one of the tweeters is failing, what's the best way to re-connect those teeny-tiny wires ?

How, or in what way, do you notice a tweeter failing? Noise or appearance? Where are you trying to reconnect the teeny wire (at the dome or at the tab by the edge)?

[Guest speedracer]

Do as John says. With those woofers; 20 ounces of fiberglass in each cabinet. We've fooled with this endlessly. You can fool with it endlessly, too, or you can put 20 ounces of fiberglass in each cabinet (which is what you will end-up doing in the end) and be done with it.

How, or in what way, do you notice a tweeter failing? Noise or appearance? Where are you trying to reconnect the teeny wire (at the dome or at the tab by the edge)?

The tweeter looks like it's rotting at the bottom ( slash like hole ), orange dust trickling out, barely hear it. Guessing it needs to be replaced Can't wait to mees with those wires !!

[RoyC]

The tweeter looks like it's rotting at the bottom ( slash like hole ), orange dust trickling out, barely hear it. Guessing it needs to be replaced Can't wait to mees with those wires !!

It sounds as if your tweeter has the typical decomposed foam under the (damaged) dome. The tweeter was likely nearing the end of its days anyway.

Regarding the blue woofer wire, I recommend removing the #1 cabinet terminal screw to gain access to the ring terminal for repair. The two ring connectors, which are attached to three blue wires (tweeter series cap, mid/woofer cap, and the woofer negative lead wire) are easy to replace if necessary.

Roy

[Guest speedracer]

It sounds as if your tweeter has the typical decomposed foam under the (damaged) dome. The tweeter was likely nearing the end of its days anyway.

Regarding the blue woofer wire, I recommend removing the #1 cabinet terminal screw to gain access to the ring terminal for repair. The two ring connectors, which are attached to three blue wires (tweeter series cap, mid/woofer cap, and the woofer negative lead wire) are easy to replace if necessary.

Roy

The Blue wire broke @ the woofer terminal, not down in the speaker (thank God !)

[JKent]

FYI:

Try Bill LeGall at:

Millersound Labs, 1422 Taylor Road, Lansdale, PA 19446, Phone 215-412-7700 Fax 215-412-0542

millerspkr@aol.com

[Guest speedracer]

FYI:

Try Bill LeGall at:

Millersound Labs, 1422 Taylor Road, Lansdale, PA 19446, Phone 215-412-7700 Fax 215-412-0542

millerspkr@aol.com

I know Bill, he's only about 20 min. from me.

[Carlspeak]

Hello Speedracer:

The driver on the right is the first-generation AR foam-surround woofer manufactured from 1969 through 1972; it is identified by its long pigtail leads and Masonite spacer visible at the edge. (By 2007 it too would have been re-foamed.) Cabinet serial numbers 54,000 -55,xxx were manufactured in mid 1971. So the driver on the right is original. Both cabinets should have #9 woofer inductors and 20-oz of fiberglass damping. Originals of that date would have used front-wired mid- and hi-range drivers.

The woofer on the left looks like the 1978 version made in USA by AR and designed for speakers like the AR-11(, AR-9. (Your image seems to show the black felt in the bolt circle.) By the time it was replaced, that driver version was probably the only one available. Likely it has been refoamed as well. It is stiffer than the first generation woofer. I do know that the AR-11 used 10-oz of trilobal polyester stuffing, so it would definitely be overdamped with that much fiberlass in an AR-3a. One might tinker with some "Fiberloft" made by Leggett sold in Joann Fabric stores- a bag is five bucks; see if it improves the bass; however the overall balance would never be identical to the early if you did that.

The best solution is to exchange your 1978 version for an early long-pigtail version. Perhaps you might contact one of the restoration folks on this site?

Please don't give up; these are nice speakers--worth the added effort.

Cheers,

John

Just acquired a new stuffing data point. Was working on Super-Modding a pair of 3a's and found white PET stuffing. Traces of yellow FG were also found; indicating the speaker had been worked on. Customer (original owner) told me he brought his speakers to AR in Canton, MA in 1991 for some refurbishing. From what I can tell, AR replaced one midrange, the AP rheostats with 15 ohm L-pads and yellow, FG stuffing with PET. I weighed the amounts removed from each speaker and got 14 oz. on one and 16 oz. on the other. Don't know if the stuffing was tri-lobal but it sure was nicely opened up. The woofer coil was not marked. The woofers were stamped AR121003-2A. WT2 one of the woofers. Its Fs was 19.7 hz. Re was 2.63 ohms. The speaker cabs ser. #'s are 81367 & 81384.

The stuffing qty seems a bit high compared to Johnieo's AR 11's 10 oz in a similar size cab. However, other factors in the makeup of the AR11 may have mitigated the lighter PET loading.

When I re-stuff the cabinets with the original PET stuffing I took out I'll measure the Fc with the woofers installed and amend this post.

Cheers,

[Carlspeak]

Ooops, discovered an error in the woofer p/n in prior post. It should read 1210003-2A. Also stamped below that p/n was "411TNB".

[Guest John Faulkner]

[q

A photo of the BACK of the drivers would be helpful to pin it down exactly, but wouldn't change the advice you will receive here. If you've got the time and like having fun with a digital camera, we'll take a look. If not, okay. It won't change anything.

It looks to me like the dust cap (center bump) has been replaced on the left-hand driver (but don't swear that) as well as the surrounds on both speakers, at the same time with the same foam.

I have another thing to ask of you. I have a suspicion. The driver on the left, the newer one, please examine it closely. As you follow the *back* of the cone toward the magnet you will find a corrugated ring of material, parallel to the big foam ring, holding the little end of the cone centered. This will be glued inside the metal basket down low. This is called a spider and is just as much a part of the cone's suspension as the big grey foam ring.

If you hold that woofer on its side (so gravity is **not** pulling "back" on the cone) and examine the spider - it should be flat. It should not be sunken or raised. Would you tell me if that spider is sunken when gravity is not pulling on the cone, please?

I have a pair of ar-3 and a pair of ar-3a, but only 1 original cloth surround woofer. When it is sitting on its magnet (cone facing up) the spider sags well down, other woofers the spider is flat - is this woofer failing?

John

[Carlspeak]

John. I believe sagging spiders only become a serious problem with woofers that are mounted facing up or down in the cabinet rather than horizontal as on the 3a's. That is, of course, unless it sagging so much it causes VC rub. Snell's early models used up-facing woofers in their cabinet configurations. Most I've worked on have sagging spiders; not only because of the mounting orientation but also because they have weight added to the cone via epoxy resin poured around the dust cap. This is a method to lower a woofer's resonant frequency at the sacrifice of efficiency. Sometimes, a new surround will help re-position the cone a bit upwards towards its original intended position with the top of the cone edge pretty much lined up with the top of the brown shim glued to the frame.

Additionally, older, Alnico woofers with fabric surrounds have very soft spiders which also appear to sag at this point in their life. As Johnieo pointed out earlier in this post, AR stiffened up the spiders to address higher SPL's. I suspect also it was because of the sagging problem and perhaps a decline in availability of the finely woven spiders used in the earliest woofers. I have published photos of a spider removed from an AR1 speaker in this forum about 1-2 yrs ago. It's quite amazing how finely woven those early spider fabrics were. I don't believe those spiders are available any longer.

I am experimenting with a method which might be useful for lowering a woofer's resonant frequency via permanent alteration of the spider's stiffness. Spiders contribute over 1/2 the total woofer's stiffness (compliance) properties. In addition to optimizing cabinet stuffing density and a few other tricks, slightly decreasing a spider's flexural regidity may provide a synergistic effect towards lowering overall cabinet resonant frequency and ultimately lower bass response. My work should be completed in the next few days. If successful, I'll publish the results in the mods/tweaks area.

[frankmarsi]

John. I believe sagging spiders only become a serious problem with woofers that are mounted facing up or down in the cabinet rather than horizontal as on the 3a's. That is, of course, unless it sagging so much it causes VC rub. Snell's early models used up-facing woofers in their cabinet configurations. Most I've worked on have sagging spiders; not only because of the mounting orientation but also because they have weight added to the cone via epoxy resin poured around the dust cap. This is a method to lower a woofer's resonant frequency at the sacrifice of efficiency. Sometimes, a new surround will help re-position the cone a bit upwards towards its original intended position with the top of the cone edge pretty much lined up with the top of the brown shim glued to the frame.

Additionally, older, Alnico woofers with fabric surrounds have very soft spiders which also appear to sag at this point in their life. As Johnieo pointed out earlier in this post, AR stiffened up the spiders to address higher SPL's. I suspect also it was because of the sagging problem and perhaps a decline in availability of the finely woven spiders used in the earliest woofers. I have published photos of a spider removed from an AR1 speaker in this forum about 1-2 yrs ago. It's quite amazing how finely woven those early spider fabrics were. I don't believe those spiders are available any longer.

I am experimenting with a method which might be useful for lowering a woofer's resonant frequency via permanent alteration of the spider's stiffness. Spiders contribute over 1/2 the total woofer's stiffness (compliance) properties. In addition to optimizing cabinet stuffing density and a few other tricks, slightly decreasing a spider's flexural regidity may provide a synergistic effect towards lowering overall cabinet resonant frequency and ultimately lower bass response. My work should be completed in the next few days. If successful, I'll publish the results in the mods/tweaks area.

FM here, WOW you're doing (great-vintage AR research) that, while I listen to the original version of "Victory at Sea" ,(cd version, my LP version is to far gone), -still great and taken directly from 'cartridge' play-back means at the factory.

With masking taped and rubber glued woofers and most LST tweeters not working except for my dedicated "Micro-Statics" tweeters on top of all four, I've pratically no effort in over 7 years, do to distractions of the real kind.

Crying here as the music tells me to do (inwardly or right-out-loud), cause that's what music does, as it makes you realize all that you see and feel in life, I'm a hap-less X-hippie from way-back, of middle class background and means.

I must confess to my over indulgence of now having 11 spare woofers, 13 spare midrange's, and sadly, a slight shortage of only 6 tweeters after all the cabinets have been restored, but only after I get off of my ass and do something. I might need four 2AX tweeters(C. '72), but I'll just use a resistor on the others after I buy them. Small care after the big guys I have to deal with.

Why have I let myself stress to utter laziness in not getting and making my AR's perfect?

If I garning nothing on this site, let me be, at least the laziest AR-guy around. Although I may have the 'where-with-all' to presue, I simply find myself just playing music and listening.

I have numerous types of 'play-back' equipment, but it always seems to be the speakers that I am listening to, regards of what repairs are due and necessary, the AR speakers are my strongest part of my system I listen to beside the actual music.

I may need some helpful help here?

Solely no-one's friend until I get with-it, my own worst 'loose-canon' when it comes to my speakers!

FM