AR 10 pi

[Guest Nigel]

Hi Bitsy;

Definitely worth repairing. Layne Audio (see links) has replacement drivers. They MAY take your old ones in trade on refurbished units.

IF you decide that you do not want them, please let us know.

Nigel

See the LINKS, and/orbelow.

http://www.speakersupply.com/AR.htm

[Guest]

I have a pair of AR10 pi speakers. One 12" woofer was damaged by a cat and both speakers look like they have to be reconed or refoamed. These speakers have a hinged panel with 3 adjustments on each switch on the top front of the speaker. My question is, are these speakers worth repairing and are there repair centers in the New York metropolitan area. (anyone want a cat?)

[Guest]

Hi

I recently purchased new woofers for my AR-11s directly from AR. They were about 260.00 canadian.

John

[rustycat]

I just salvaged a working(?) pair of AR-10 pi from an end-of-yard-sale "free" pile.

Totally unfamiliar with these, but recognized the name quality and lugged them home. If weight is any measure of quality, these are the greatest speakers ever!

The woofers need re-foaming, and the tweeters and sound switches all work. However, there is on each speaker what looks like another tweeter with a grating covering it, from which no sound is produced.

Is this normal? If so, what does this device do?

Also, can you recommend any type of test beyond hooking them up to a stereo system to determine that both speakers are in good working order?

Aside from the re-foaming, the only other obvious problem is the veneers are cracked and peeling in spots, and the grills are gone.

Not bad, eh?

Thanks in advance!

[JKent]

Bitsy

There is a member here named Minh Luong, username mluong303 who is in NYC and has received rave reviews from some members for his speaker repair work. I'd suggest you look up his profile and send him an email with your question. Another favorite here is Bill Legall of Millersound in PA, but in NYC Minh is probably your man.

Good luck

Kent

[Guest Bret]

>The woofers need re-foaming, and the tweeters and sound switches all work. However, there is on each speaker what looks like another tweeter with a grating covering it, from which no sound is produced.<

That other tweeter is actually a midrange driver. "Good" speakers used to commonly have three drivers per cabinet.

It should be producing sound. In fact, it should produce a lot of sound. There are a lot of reasons they might not be playing.

>Also, can you recommend any type of test beyond hooking them up to a stereo system to determine that both speakers are in good working order?<

Let me preface the rest of this note by telling you this: What you have there is a very fine, extremely expensive (originally), "flagship" speaker from AR. At one time it was the top-of-the-line. You might want to look at the sales brochures that are in the forum's library section. IF you will take the time(mostly), effort(some), and money (not too much) to do a good and thorough job of restoring them I think you will be very glad you did whether you tend to listen to Tool or harpsichord. They will do something most speakers won't.

Do not play the speakers if they need new surround foam. The foam helps keep the cone "centered." If you play them without the surround intact, there is a fair chance of damaging them beyond simple and cheap repair. You certainly can't tell anything about how they sound with a rip in the surround. Really - you can't tell *any*thing about how they sound because sealing the cabinets changes everything and the foam's gotta be there to seal the cabinet.

As for testing the speakers, I assume you've already hooked them up to a receiver and played them and that's how you know there is no sound from the midrange, or did the former owners tell you that?

If they were mine, to test the midrange, I would take the drivers out of the cabinets, carefully. If you have access to a volt/ohm meter test for any resistance. If there is infinite resistance, it's possible that the speaker is, really, dead. It's also possible that one of the tiny, tiny lead-wires has been broken somewhere you can see and get-to and might be fixable.

If you get resistance, or if you do not have access to an ohm meter, then I would (PLEASE BE CAREFUL) connect my receiver to the midrange (out of the cabinet), turn the bass all the way down on the receiver, and ***barely*** crack the volume. If the midrange driver makes any noise at all, chances are your midrange drivers are fine and we have to look elsewhere for a problem. Do not try to listen to the midrange this way, just check to see if it'll make any noise. If it does, turn it off immediately. Playing a driver without its crossover attached is a really bad idea.

Re-foaming the woofers - I've had very satisfactory work done on a timely basis one place and one place only: Millersound (if you search that term you'll get the address and phone number in PA). You can replace the foam by yourself, most likely, but you really cannot afford to make an error because if you goof it up you may render the speaker unfixable. I don't want to price another man's work, but I'll tell you I suspect you are talking about less than $100 to have both speakers "professionally" refoamed and Millersound would be in a good position to tell you if there are other problems with the woofers.

Reasons your midranges might be good but might not work include: Someone screwed-around with the crossover and left something disconnected; A capacitor died; Someone pulled the midranges out of the cabinet (for some reason) and screwed them back in without reconnecting the leads on the back; The switch is bad; Someone pulled the wires loose from the back of the switch; etc. The first order of business is to see if the drivers, themselves, are bad.

If you need to replace the midranges because they are dead, the only reasonable solution is to match them with the exact same model numbers (on the back) that you might find for sale on eBay. Some other drivers will FIT in the cabinet and look pretty-much the same, but are entirely wrong. The same midranges in your 10pi's were also used in AR-11 speakers, so used drivers come available pretty frequently. You might have to shop eBay for a while before any become available.

I guess to know how best to help you do this as inexpensively as possible, but still well, we'll have to know more about how far you are willing to go to get them singing again.

Would you describe them some more? Do you have black on brass badges or silver on black? Are your tweeters light colored or black? Are there fuse holders on the back by the terminals?

Bret

[JKent]

here is info on Millersound, but don't overlook Minh--he is probably just a subway ride away

Bill LeGall at:

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

millerspkr@aol.com

[RoyC]

What Bret said :-)!! ...and another vote here for Millersound!

Kent, rustycat is probably not the same New York City area member who started this thread.

Roy

[JKent]

>Kent, rustycat is probably not the same New York City area

>member who started this thread.

oops! never looked at the date of the original post. 2001. Better late than never? ;-)

[rustycat]

>>The woofers need re-foaming, and the tweeters and sound

>switches all work. However, there is on each speaker what

>looks like another tweeter with a grating covering it, from

>which no sound is produced.<

>

>That other tweeter is actually a midrange driver.

>"Good" speakers used to commonly have three drivers

>per cabinet.

>

>It should be producing sound. In fact, it should produce a

>lot of sound. There are a lot of reasons they might not be

>playing.

>

>>Also, can you recommend any type of test beyond hooking

>them up to a stereo system to determine that both speakers are

>in good working order?<

>

>Let me preface the rest of this note by telling you this:

>What you have there is a very fine, extremely expensive

>(originally), "flagship" speaker from AR. At one

>time it was the top-of-the-line. You might want to look at

>the sales brochures that are in the forum's library section.

>IF you will take the time(mostly), effort(some), and money

>(not too much) to do a good and thorough job of restoring them

>I think you will be very glad you did whether you tend to

>listen to Tool or harpsichord. They will do something most

>speakers won't.

>

>Do not play the speakers if they need new surround foam. The

>foam helps keep the cone "centered." If you play

>them without the surround intact, there is a fair chance of

>damaging them beyond simple and cheap repair. You certainly

>can't tell anything about how they sound with a rip in the

>surround. Really - you can't tell *any*thing about how they

>sound because sealing the cabinets changes everything and the

>foam's gotta be there to seal the cabinet.

>

>As for testing the speakers, I assume you've already hooked

>them up to a receiver and played them and that's how you know

>there is no sound from the midrange, or did the former owners

>tell you that?

>

>If they were mine, to test the midrange, I would take the

>drivers out of the cabinets, carefully. If you have access to

>a volt/ohm meter test for any resistance. If there is

>infinite resistance, it's possible that the speaker is,

>really, dead. It's also possible that one of the tiny, tiny

>lead-wires has been broken somewhere you can see and get-to

>and might be fixable.

>

>If you get resistance, or if you do not have access to an ohm

>meter, then I would (PLEASE BE CAREFUL) connect my receiver to

>the midrange (out of the cabinet), turn the bass all the way

>down on the receiver, and ***barely*** crack the volume. If

>the midrange driver makes any noise at all, chances are your

>midrange drivers are fine and we have to look elsewhere for a

>problem. Do not try to listen to the midrange this way, just

>check to see if it'll make any noise. If it does, turn it off

>immediately. Playing a driver without its crossover attached

>is a really bad idea.

>

>Re-foaming the woofers - I've had very satisfactory work done

>on a timely basis one place and one place only: Millersound

>(if you search that term you'll get the address and phone

>number in PA). You can replace the foam by yourself, most

>likely, but you really cannot afford to make an error because

>if you goof it up you may render the speaker unfixable. I

>don't want to price another man's work, but I'll tell you I

>suspect you are talking about less than $100 to have both

>speakers "professionally" refoamed and Millersound

>would be in a good position to tell you if there are other

>problems with the woofers.

>

>Reasons your midranges might be good but might not work

>include: Someone screwed-around with the crossover and left

>something disconnected; A capacitor died; Someone pulled the

>midranges out of the cabinet (for some reason) and screwed

>them back in without reconnecting the leads on the back; The

>switch is bad; Someone pulled the wires loose from the back

>of the switch; etc. The first order of business is to see if

>the drivers, themselves, are bad.

>

>If you need to replace the midranges because they are dead,

>the only reasonable solution is to match them with the exact

>same model numbers (on the back) that you might find for sale

>on eBay. Some other drivers will FIT in the cabinet and look

>pretty-much the same, but are entirely wrong. The same

>midranges in your 10pi's were also used in AR-11 speakers, so

>used drivers come available pretty frequently. You might have

>to shop eBay for a while before any become available.

>

>I guess to know how best to help you do this as inexpensively

>as possible, but still well, we'll have to know more about how

>far you are willing to go to get them singing again.

>

>Would you describe them some more? Do you have black on

>brass badges or silver on black? Are your tweeters light

>colored or black? Are there fuse holders on the back by the

>terminals?

>

>Bret

Bret,

Thanks for your prompt reply. I have attached some pix I took of the speakers rather than try to describe.

I did test them by listening, and was quite impressed at the sound quality despite the missing foam. However, the midranges are mute.

If you can offer further advice, or refer me to a reasonably priced repair shop in metro Boston, MA, I would be grateful.

Thanks to all of you!

2339.txt

2340.txt

[dynaco_dan]

Hi there;

Nice speakers. MMMMMMM

I suggest that you try a 1 1/2 volt, not more, battery test across the two mid front wires.

Make certain that you do not have an amp connected to the speakers.

You should, or not, get a quick bleep, when you touch the battery connections.

This is a beautiful opportunity to service, or at least troubleshoot, with a front wired driver.

[Guest Bret]

You picked these up at a yard sale. . .for free. . . Yeah, I'd say you did pretty well. What kind of receiver are you using / will use with these? You need a big-one. A real monster would be nice.

>If you can offer further advice, or refer me to a reasonably priced repair shop in metro Boston, MA, I would be grateful.<

I'm sorry to hear about the midranges. You tried them as I described, yes?

I'm too far from Boston to be of any help with a repair shop. You really don't need to pay someone else to do the labor that needs doing - unless you don't want to, or are uncomfortable doing it. My biggest fear with a repair shop is that they might try to do something "custom" to a pair of speakers that doesn't need any customization. The crossover in those is pretty. . . well, it's unique. They have to go back together just like they were built.

You think you're impressed now. . . wait until you get them fixed.

I'm glad you posted photos. It looks to me like someone's monkeyed-with the midrange before. They probably decided that it wasn't worth the price of two new midranges to fix them. Well, the irony is that two new midranges would have been wrong, anyway. Used midranges are the proper midranges and they are less expensive (usually) than new drivers.

You are very lucky. The pair you have was made before they changed some things. Both the woofers and the tweeters were particular to that vintage of the AR-11 and AR-10pi and are superior in many ways to what came later. I repeat my advice - have the surrounds done professionally and carefully. The cone material on the woofer is irreplaceable and "relatively" rare. The foam needs to be "extra-floppy" and not just "the right size." The resonance should be in the mid-to-upper teens. Millersound knows what I just said and why it is important.

Big picture advice:

Buy a pair of matching midranges from eBay even if it takes months to do so. It is incredibly important that the model numbers actually **match** yours. You don't want "official replacement drivers" with a different number on them.

Pack-up the woofers and send them to Millersound for refoaming. He'll look-at the spiders and can tell if the voice-coil or former have been damaged by playing them with rotten surrounds. Not everyone who refoams bothers to do it right. Millersound does. (I'm sure others do, too, but why reinvent the wheel?)

How are you with a soldering gun?

Alternatively, does anyone in the Boston area know of someone who would take-on testing a 10pi crossover's components?

Bret

PS - I've got a soft-spot for 10pi's. I listen to a pair I restored just about daily, and every few weeks I get to hear a friend's pair we also restored, which I suggested he buy when they were new, back in the 70s - those were in our dorm room for a while. "Walk This Way," "Year of the Cat," "Barracuda," "Lay Down Sally," and especially "Peg" all sound great on 10pi's even if you bought them to play the opening theme from Star Wars.

[rustycat]

>You picked these up at a yard sale. . .for free. . . Yeah,

>I'd say you did pretty well. What kind of receiver are you

>using / will use with these? You need a big-one. A real

>monster would be nice.

I have an HK amp (not sure of model no.) which seems to kick butt pretty well.

>>If you can offer further advice, or refer me to a

>reasonably priced repair shop in metro Boston, MA, I would be

>grateful.<

>

>I'm sorry to hear about the midranges. You tried them as I

>described, yes?

Will attempt voltage test tonight.

>I'm too far from Boston to be of any help with a repair shop.

>You really don't need to pay someone else to do the labor that

>needs doing - unless you don't want to, or are uncomfortable

>doing it. My biggest fear with a repair shop is that they

>might try to do something "custom" to a pair of

>speakers that doesn't need any customization. The crossover

>in those is pretty. . . well, it's unique. They have to go

>back together just like they were built.

>

>You think you're impressed now. . . wait until you get them

>fixed.

>

>I'm glad you posted photos. It looks to me like someone's

>monkeyed-with the midrange before. They probably decided that

>it wasn't worth the price of two new midranges to fix them.

>Well, the irony is that two new midranges would have been

>wrong, anyway. Used midranges are the proper midranges and

>they are less expensive (usually) than new drivers.

>

>You are very lucky. The pair you have was made before they

>changed some things. Both the woofers and the tweeters were

>particular to that vintage of the AR-11 and AR-10pi and are

>superior in many ways to what came later. I repeat my advice

>- have the surrounds done professionally and carefully. The

>cone material on the woofer is irreplaceable and

>"relatively" rare. The foam needs to be

>"extra-floppy" and not just "the right

>size." The resonance should be in the mid-to-upper

>teens. Millersound knows what I just said and why it is

>important.

>

>Big picture advice:

>

>Buy a pair of matching midranges from eBay even if it takes

>months to do so. It is incredibly important that the model

>numbers actually **match** yours. You don't want

>"official replacement drivers" with a different

>number on them.

>

>Pack-up the woofers and send them to Millersound for

>refoaming. He'll look-at the spiders and can tell if the

>voice-coil or former have been damaged by playing them with

>rotten surrounds. Not everyone who refoams bothers to do it

>right. Millersound does. (I'm sure others do, too, but why

>reinvent the wheel?)

I don't mind spending $100 to get the woofers done right, IF I can be reasonably sure there are no other problems with the rest of the units. Any way to determine this?

>How are you with a soldering gun?

It's been a few years since metal shop class, but I do own one. Why?

>Alternatively, does anyone in the Boston area know of someone

>who would take-on testing a 10pi crossover's components?

>

>Bret

>

>PS - I've got a soft-spot for 10pi's. I listen to a pair I

>restored just about daily, and every few weeks I get to hear a

>friend's pair we also restored, which I suggested he buy when

>they were new, back in the 70s - those were in our dorm room

>for a while. "Walk This Way," "Year of the

>Cat," "Barracuda," "Lay Down Sally,"

>and especially "Peg" all sound great on 10pi's even

>if you bought them to play the opening theme from Star Wars.

>

Bret - Is there a posting anywhere on this or another audiophile site where I might find a guide to testing these speakers? I am excited about the possibility of restoring them, but apprehensive about procedures. I want to make sure I don't cause any further damage.

Thanks again!

[KlausDK]

Hi Rustycat

I am another very happy owner of an early set of 10Pi speakers like yours. I have previously had a lot of help from Bret and RLowe regarding this model, if you search the forum for "AR10Pi" and take a look in the topic # 8017 named "AR10Pi crossover schematics" you'll find a lot of help regarding restoration of these speakers.

I had to refoam the woofers as well (but did so myself) and both my my tweeters were blown. I spent quite a lot of time (and money as well) to restore these speakers, but you will get a speaker of a quality and sound that money can't buy today.

However, to get the optimal sound out of your AR's, you will have to replace a few of the capacitors in the crossover as well, I guess that is what Bret alluded to with this question on the soldering iron. The cross-over lay-out for this speaker is very complex and like almost no other cross-over ever made, but as you will see from Brets advice in the post referred to above, the two most important capacitors to replace is the 10 myF for the tweeter and the 40 myF for the midrange.

Regarding testing the drivers, a cheap multimeter will allow you to test the resistance without any chance of damaging the drivers. Unscrew the midrange units, with the speaker in a horizontal position, front plate facing upwards; carefully lift the driver and disconnect at least 1 of the the wires before testing. Resistance should be in the 3-5 Ohm range depending on the resistance in the probing wires and how well you manage to get contact to the speaker poles.

Best regards Klaus

[rustycat]

Guys --

Here's the latest. Multimeter test registered either zero when I touched the terminals disconnected from the lead wires, or spun wildly when I touched the ends of the front wires while hooked to the terminals.

I tried Bret's advice to hook up the driver directly to my amp (HK 3380) at minimum volume and got no sound.

I only tested one midrange driver, but am guessing the same will occur on the other.

At this point, unless you feel there is something else I can do, I am willing to spend at most $100 to get these operational again, so I will begin the search for replacement midrange drivers and refoam myself using a kit.

Klaus, I couldn't find the topic on AR-10pi schematics, so if you have a copy, can you email it to me?

Bret, thanks again for all your advice and encouragement.

I'll let you know how I make out.

Cheers!

[Guest Bret]

I'm not sure what you mean, exactly, when you say "testing" the speakers. You can't test the woofers until they are fixed and then to do it right you need equipment.

If the tweeters work, consider them tested for the time-being.

I think you've done just about all the testing you need to with the possible exception of the capacitors. There's not much else to break. You've determined that the midranges are bad.

Klaus was talking about this:

http://www.classicspeakerpages.net/dc/dcbo...ing_type=search

It pretty-much comes down to making sure that all your drivers work, changing the capacitors, and plugging them into something. It's as much trouble to test the capacitors as change them. On the other hand. . .changing the capacitors in a 10pi is just. . . well, it's just. . . it's indescribable is how it is. It needs doing, anyway.

I think you are talking about more than $100 even if you do the minimum and even if you do it all yourself. If you decide it isn't worth it to you, there are a lot of people who wouldn't feel that way.

Let us know. 10pi's in the garbage is. . . too horrible to contemplate.

Bret

[rustycat]

One more update -- I ran the multimeter test again with the midrange drivers in the cabinets, and each registered 1.8 at the 200 and 2000 range. Once I upped the range to 20K, I got zero.

Does this shed any light on the viability of the drivers? Is it a capacitor issue?

How do you even access the crossovers? Can you disassemble the cabinets, or do you have to reach in and remove all the insulation (hopefully its not fiberglass -- I'm allergic)?

Any and all responses are greatly appreciated!

[ar_pro]

You want to use the lowest possible range on your meter.

It's weird that both drivers are bad - tweeters are the most common problem, followed by damaged woofers. I'm not even sure how (without really trying to) you could burn out a midrange without damaging the tweeter, too.

Anyway, the proper midrange drivers can most likely be obtained from ebay, but I have no idea of the price. As mentioned above, its important that you get the correct driver - a commonly-sourced pair would be ideal.

All repairs to the crossover & switches will have to go through the woofer hole. Not sure if AR was still using fiberglass at the time, but I wouldn't bet against it. Save every bit that you pull out in a pair of kitchen trash bags - you'll need it again.

Take this opportunity to remove the tweeters, and test them one more time - first for impedance, and then using the previously suggested method of connecting them to an amplifier, with the tone controls reduced to zero, and LOW volume! Maybe you'll get lucky, and the problem is just a broken connection.

[KlausDK]

Never connect the tweeters directly to an amplifier use a capacitor of 6-10 myF in series. I am sure AR-pro above suggests you to test the midrange domes again, even with those extremely care has to be taken if you connect them direct to an amplifier (as described by Bret above) in order not to damage the coil.

BRgds Klaus

[ar_pro]

Yes, absolutely! Thank you.

[Guest Bret]

I didn't realize how new all this would be to you. I hope I wasn't too confusing by skipping to Chapter 2.

No, don't disassemble the cabinets.

Your 10pi's: The brass badges say "first generation." The fact that there are no fuse holders and that your tweeters are black says "First generation, but second version." Your woofers have cone material that is different from what comes later; it is somewhat "fuzzy" to the touch and "deader" if you thump it than those that came later. Your tweeters are likely of very good quality, they are probably first generation of the ferrofluid-filled drivers, and that was another AR first, so you've got another example of a first of a first.

That means that you have a pair that was being made when AR still cared about them. They were hoping that this "model year" would help them recapture some lost market share as the 3 series got a little long in the tooth and technology got better. Later, QC became a problem, but not when yours were built. AR was still really proud of its heritage and ready to move to the next-level.

To restore them the main phases are:

A) Get a full set of working drivers

Do any work necessary on the crossover

C) Do any work you want on the cabinets

D) Reassemble the system paying attention to every seal including the ones around the binding posts (that tend to loosen over the years).

Typically this means that you will have the individual drivers in and out of the cabinet a couple of times, but if you really want to restore these, I'd suggest that at this stage you take the tweeters, mids, and woofers out of the cabinets and set them aside (not near any audio/video tapes, not on the TV, not on top of your computer).

THAT IS FIBERGLASS IN THERE ! I didn't know a person could be allergic to fiberglass, but if you are you've got a problem.

If you have a friend who is willing to put-on gloves and /or a mask, you might ask them to remove, as completely as possible, the fiberglass into two kitchen garbage bags; one bag for each speaker. The fiberglass was weighed and put in the cabinets to achieve a specific "Q" - - - nevermind, we can talk about that later. Put it aside and save it.

Just know that it's important that the same amount that came out of the cabinet goes back into the cabinet. 1/10th of an ounce here and there isn't going to goof anything up, and even an errant 1 ounce probably would not hurt anything, but stuffing 30 ounces back in one cabinet and 10 in the other, will. (there is approx 20 ounces in each cabinet)

After as much fiberglass as can be removed is removed, you might get that same friend to thoroughly vacuum the inside of the cabinets for you. As long as they don't get rugby-rough, they really shouldn't be able to hurt anything.

You will need to replace some capacitors. The leads on the old capacitors are wound tightly around a soldering ring connected to a horizontal post of soldering rings stuck to the cabinet about midway in, behind the woofers. You have to get intimate with all of this and there is fiberglass everywhere unless a thorough vacuum job was done.

There is darn little room, no light, and no easy way to get at the capacitors and/or resistors. I would recommend that you consider capacitor replacement to be a multi-night endeavor. If you are prone to get impatient (as I am) you might want to have someone else do it.

It isn't hard labor or anything, but you can't afford to forget where that wire over there, and this resistor here, and that capacitor over there were connected. Sometimes it is hard to see where each thing is connected because you cannot see the entire lead at one time. You can't afford to to get it wrong. Trust me when I say that in these speakers, working on them as you have to (through the woofer hole) in these tiny spaces, with a hot soldering iron, it is very easy to get "turned-around." I found it easiest to see what I was supposed to be doing using a small, hand-held mirror, but trying to work like that(in the mirror)is maddening.

Hopefully your eyes are better than mine and you won't have as much trouble as I had.

Depending on what type of capacitor you get for replacements, they may be considerably larger or smaller than the originals. There may be a shortcut, but let's deal with the realities of what parts you decide to buy rather than speculating about all the various things you might do in each multiple-choice case.

With all that speaking in favor of leaving the crossovers alone, wouldn't it be ok to not-replace the capacitors? No, not really. If you leave the old caps in, you'll wonder what all the fuss is about with the 10pi, because the speaker won't sound all that great. Those capacitors are probably 31 or 32 years old this year. They weren't that wonderful by today's standards to start-with, although they were as good as could be had when they were new. We have found them, almost all of them, to have "issues" once they reach this advanced age.

I just wouldn't waste my time fixing woofers or buying "new" midrange speakers for them if I weren't willing to change the capacitors (with the possible exception of the 2500uF capacitor, for reasons we can discuss another time).

If you measured the impedance of the midranges with them connected to the crossover - you might have been measuring the crossover, not the midrange speaker. If you could get no sound from the midranges connected directly to your receiver, I'd say your midranges are dead. When I looked at the photo you posted I saw what appears to be a big glob of solder where a little bitty tiny wire should be. I might try to fool around with that, but I don't know how to instruct you to do it. I'd be interested in why all that solder is there, and I'd start by removing it. Then I'd see if a less ugly fix were possible. (I'm guessing, long-distance, that no fix is possible.)

While you are fixing the woofers and letting the glue dry and before you get into the capacitors would be a great time to do whatever you are going to do with the cabinets. I'm not a cabinet-guy. I take mine elsewhere and have a furniture restoration pro do it. I fig'r it costs less than my doing it two or three times for a questionable result. There are people on this forum, and many, many postings already here, about the best way and products to use to restore the original finish if you decide to go that route. Just use the "search" feature and it'll get you there.

The woofer repair is a whole other subject. Do you shim the voice coil like is shown in many do-it-yourself videos? (probably not) How do you make sure that your repair is centered, up-and-down, on the "0" plane when the glue dries? (important) How do you tell when the foam is truly centered side-to-side? (equally important) Is the spider flat? Is it attached all the way around? Do you have the right foam surround? (floppy is important to the design, not just a "picky" preference, and there are lots of non-floppy options out there)

All of this will be easier to step-by-step through than it is to describe (or read) all at once.

Anyplace you'd like to start would be a start. If it weren't a rewarding journey I wouldn't suggest you take the trip.

So, tell us which part you want to do first, and let's focus on that.

And a "by the way." If you try to email me and I don't respond, don't get insulted. I stopped using the email address I registered with some time ago, so that email often goes unread.

[rustycat]

Bret --

Seeing as how you are strongly recommending replacing capacitors, I need some idea of how much replacements will cost (I'm guessing Radio Shack caps are not applicable) before proceeding.

If it is too prohibitive, then I will forgo that and just focus on refoaming the woofers and searching for midranges.

[Guest Bret]

Go out to Parts Express on the web and price-out a 10uF, 20uF, 40uF, and 100uF capacitor. The critical cap is the 10uF. I'd buy something "suitable" but not too expensive for most of the (like 7 or 8) and parallel a 2 or 3 of "high quality" along with it.

The 40uF could cost as little as $4 to make-up or as much as $20.

I hope someone else has the time, right now, to guide you. I'll be back, but not for a couple of days.

Happy parts shopping.

Bret

[Guest Bret]

I caught a break, so I'll try to explain what I was talking about.

If you will, again, do a search of this expanding message board you will find hundreds of discussions about capacitors and almost as many opinions. You will also find explanations of why all capacitors are not exactly the same from a materials and construction standpoint. I won't repeat any of that here. It is enough that you know that you need look no further than these discussions for what is probably the best explanation of "why" that you will ever find; if you are curious.

You certainly don't need to go further than parts express' online store to find whatever capacitors you choose to use.

On this page:

http://www.partsexpress.com/webpage.cfm?WebPage_ID=61

you will find a lot of different brands of capacitor.

At the bottom of the list of brands you will see "Non-Polarized Electrolytic Caps." Clicking on that link, you will find that a 100uF non-polar (important) electrolytic capacitor can be purchased for $1.85. The 10uF is $0.55 and the others you need are priced in-between those. Even a 500uF (you would need five of them in each speaker) in a quantity of 10 are $5.44 each.

For our purposes, the smaller values are more important than the larger values. If you do not replace the 2500uF capacitors but continue to use the old ones, my limited experience is that you will not notice.

Focusing on the 100, 40, 20, and 10 - the 10uF is very important. Because of where and how it is used the 40uF is more important than the 20uF. The 100uF is important (they all are) but is probably less than half as important than the 40uF.

It would be better to use these new, very inexpensive non-polar electrolytic capacitors than to leave your current 30 year old electrolytic capacitors in the speakers.

You will notice that there is no "40uF" capacitor listed. By paralleling a 33uF and a 6.8uF together, you "build" a 39.8uF capacitor which is close enough to 40uF. In this way a 17uF and a 2.7 "becomes" a 19.7uF which is close-enough. It is better to be a little under than to be a little over. 19.7 is preferable to 20.3.

Paralleling capacitors is what you do to make-up a value that you do not have.

Electrolytic capacitors have problems with aging. If you use electrolytic capacitors in your restoration, in a decade you will need to change them again.

Going back to the website you'll also see "Solen Metalized Polypropylene." These are widely used by quality-conscious sorts. Polypropylene or Poly caps, for short, do not have the same issues with aging. They should not change their values in our lifetimes. For that reason, some people prefer to use them. Other people prefer to use the same "type" of capacitor that they removed. A Solen 10uF capacitor costs $4.48 compared to the unbranded electrolytic at $0.55. The 100uF Solen costs $27.01 compared to $1.85 for the electrolytic.

Then there are boutique capacitors at boutique prices. For instance, a 10uF Auricap Metalized Film capacitor is $51.45 and even that's not the most expensive capacitor out there.

Some of us use inexpensive Dayton Poly caps. A 10uF capacitor is $3.15 compared to the Solen at $4.48. They see no reason to spend the $1.33 difference to get Solen's brand name.

Some of us have found what seems to be a reasonably priced boutique capacitor that we think we like for whatever reason. A 10uF is $9.35. That's just more than twice what a Solen costs, but only 20% of the price of an Auricap. Those would be North Creek Music's "Zen" polypropylene capacitors.

An important digression:

"By-passing" capacitors is exactly the same thing as paralleling two or more capacitors. People call it "by-passing" a capacitor when they are being "all sophisticated and stuff" (or crazy depending on your religion) about why they did it.

The goal in by-passing is to change the nature, or the smoothness, of the "base," or primary, larger capacitor. For some people finding the right combination is the subject of many hours of trial and error. Some people believe the whole subject is poppycock.

I've fooled-around with "by-passing" only enough to determine that it does change things. In each case I have done it, the difference it has made has been a subjective improvement.

So, you might want to consider doing something like this:

Buy a Dayton 8.2uF capacitor for $2.75 and a Jantzen 1.5uF metalized film for $1.83 and make-up a 10uF that way. Or a 5.1uF Dayton for $1.95 and pair it with a 4.7uF "Zen" for $4.75 and have $6.70 in each of the tweeter capacitors, or some other combination that might yield a better result than using inexpensive capacitors by themselves.

If you do that for the 10uF and 40uF values and use only Daytons for the 20uF and 100uF, you can feel better knowing that you've put the money where it matters most.

Ken Kantor (a regular contributer here and one-time Head Honcho at AR) will tell you that changing the TYPE of capacitor (from eletrolytic to poly) will change the sound of the speaker. I can vouch for that. If you use poly capacitors you may find you need to turn the tweeter and midrange driver down in order to get a smooth, balanced, sound out of your speakers.

You even might try mixing a 10uF eletrolytic with a .0047uF Metalized Film capacitor. I haven't tried it, but I want to.

AND - you also have to think it terms of "trouble" and "size." Is it worth $5.00 to you to spend an extra 30 minutes soldering and trying to find somewhere to stick two capacitors on the board instead of one?

Enough (too much) for now.

[Pete B]

>Guys --

>

>Here's the latest. Multimeter test registered either zero when

>I touched the terminals disconnected from the lead wires, or

>spun wildly when I touched the ends of the front wires while

>hooked to the terminals.

>

>I tried Bret's advice to hook up the driver directly to my amp

>(HK 3380) at minimum volume and got no sound.

>

>I only tested one midrange driver, but am guessing the same

>will occur on the other.

>

>At this point, unless you feel there is something else I can

>do, I am willing to spend at most $100 to get these

>operational again, so I will begin the search for replacement

>midrange drivers and refoam myself using a kit.

>

>Klaus, I couldn't find the topic on AR-10pi schematics, so if

>you have a copy, can you email it to me?

>

>Bret, thanks again for all your advice and encouragement.

>

>I'll let you know how I make out.

>

>Cheers!

Hi since you have clearly stated a cost goal of $100 I'm going to give you another opinion on the capacitors. Blind tests suggest that capacitor type makes little difference in speaker applications. I find this to be especially true if you provide a resistor in series with a film cap to match (approximately) the ESR of the electrolytic that you're replacing. I have posts in the Advent section where I do such a test under A/B conditions.

I suggest that you build up your caps from Madisound surplus, or any low cost quality surplus supplier, note that a 10uF is $.90, you can use 4 to get the 40 uF etc:

http://www.madisound.com/catalog/index.php?cPath=5_12

I suggest a .33 to .47 ohm resistor in series with film caps generally, if the ESR is not known. I suggest .47 for this application. Either value is far better than zero.

You might just use an NP electrolytic for the 100 uF to stay within your budget, and you could always swap it out later if you change your mind. I prefer the Bennic NPs from Madisound.

Another source for poly film caps, with excellent (not surplus) prices: http://zalytron.com/caps.html

You might want to check my capacitor myths thread also:

http://www.classicspeakerpages.net/dc/dcbo...ing_type=search

and:

http://www.classicspeakerpages.net/dc/dcbo...ing_type=search

I can certainly understand keeping rebuild costs down especially if these are not your primary speakers.