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draftingmonkey

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Guest Bret

>Another new project for later this year LOL.<

Depending on what else is in the pipeline, you might want to move this project up on the schedule. I can't remember what all you have, but if you don't have 10pi's, prepare yourself for a treat. Oh, I'm not saying they are the greatest thing since sliced bread, but they are particularly fun to listen-to.

BTW - the crossovers in these are an absolute nightmare to work on in the cabinet. I'm not suggesting that you remove and rebuild the crossovers, but it might be easier than trying to cope with that soldering post.

I haven't seen a wrecked 10pi resistor, but I'm working off a very small sample.

There's something I have not done to mine yet. Someone from Europe sent me a pair of new NPEs to replace the 2500uf caps in mine. If you have any faith in other people's hearing (not that it can be as good as calibrated lab equipment)I might be motivated to go ahead and do what I've been intending for a year or so.

If it turns-out that the difference in new and old is inaudible, or even only subtly maybe pseudo-audible kinda, there's a restoration step it would be truly worthwhile not to have to sweat. 2500uF caps ain't cheap.

I find it amazing that the 10pi and 11 can share drivers. The crossovers are so different.

That's a nice snag for $100. If you run across another set like that (the stinkin' grills are worth $100), I know of someone who would be really happy to double your money and take 'em off your hands.

All you need is a pair of AR-14s to use as stands and pull 'em away from everything, switch them into 4pi and. . . zowie. (Am I allowed to say "zowie" on a public forum?)

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  • 2 weeks later...
Guest keep_hope_alive

i just got a pair of AR-10 PI speakers that need the woofers re-coned. they look good otherwise - maybe a 7 out of 10 for the cabinet (without cleaning yet) - no grills. i was searching around for some additional info on them and ran across this thread. while i enjoy a nice set of speakers like the next guy i just don't see these at home in my, well home. should i just pass them on to someone who will appreciate them? looks like i can get them re-coned for around $55 from Layne Audio. i pulled one woofer and was impressed by the basket construction. if i do re-cone them should i replace the fiberglass insulation with polyfill or leave the old stuff?

i must admit the 2500uF cap surprised me. it looks like an impressive crossover network. anyone got the schematic?

ideas?

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Guest keep_hope_alive

i kept digging and found the schematic and a lot more. you guys have really gone in depth with these speakers in other posts. i have a lot of reading to do.

sounds like i should start by testing the mids and tweeters before i make a decision.

do not worry, i will not hurt them in my testing

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  • 3 weeks later...

>>Another new project for later this year LOL.<

>

>Depending on what else is in the pipeline, you might want to

>move this project up on the schedule. I can't remember what

>all you have, but if you don't have 10pi's, prepare yourself

>for a treat. Oh, I'm not saying they are the greatest thing

>since sliced bread, but they are particularly fun to

>listen-to.

>

>BTW - the crossovers in these are an absolute nightmare to

>work on in the cabinet. I'm not suggesting that you remove

>and rebuild the crossovers, but it might be easier than trying

>to cope with that soldering post.

>

>I haven't seen a wrecked 10pi resistor, but I'm working off a

>very small sample.

>

>There's something I have not done to mine yet. Someone from

>Europe sent me a pair of new NPEs to replace the 2500uf caps

>in mine. If you have any faith in other people's hearing

>(not that it can be as good as calibrated lab equipment)I

>might be motivated to go ahead and do what I've been intending

>for a year or so.

>

>If it turns-out that the difference in new and old is

>inaudible, or even only subtly maybe pseudo-audible kinda,

>there's a restoration step it would be truly worthwhile not to

>have to sweat. 2500uF caps ain't cheap.

>

>I find it amazing that the 10pi and 11 can share drivers. The

>crossovers are so different.

>

>That's a nice snag for $100. If you run across another set

>like that (the stinkin' grills are worth $100), I know of

>someone who would be really happy to double your money and

>take 'em off your hands.

>

>All you need is a pair of AR-14s to use as stands and pull 'em

>away from everything, switch them into 4pi and. . . zowie.

>(Am I allowed to say "zowie" on a public forum?)

Hello Bret did you get a chance to try the new 2500 caps yet I just picked up some 10pi for 200.00

Thank you

JIm

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>Hello Bret did you get a chance to try the new 2500 caps yet I just picked up some 10pi for 200.00 <

You're just trying to make me jealous, aren't you?

WHERE are you people shopping??!! I was happy to pay that much for NOS tweeters!

And why doesn't anyone ever think of poor li'l ol' me down here in Dixie where one, MAYbe two pairs of those things were ever shipped??!!

Hey guys, if you run across $100-200 10pi's you don't want to buy, let me know!

But to answer your question: No, I never got around to it. If you are to that stage of restoration I will get to it quickly and report what I think, plus what a "blinded" listener thinks. On the other hand, how does one "form" those in a speaker?

Did you get black tweeters or the cream-colored ones?

A friend used to take big caps like that and plug them into . . . no, I think I'd better stop there and skip the liability.

Bret

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>>Hello Bret did you get a chance to try the new 2500 caps

>yet I just picked up some 10pi for 200.00 <

>

>You're just trying to make me jealous, aren't you?

>

>WHERE are you people shopping??!! I was happy to pay that

>much for NOS tweeters!

>

>And why doesn't anyone ever think of poor li'l ol' me down

>here in Dixie where one, MAYbe two pairs of those things were

>ever shipped??!!

>

>Hey guys, if you run across $100-200 10pi's you don't want to

>buy, let me know!

>

>But to answer your question: No, I never got around to it.

>If you are to that stage of restoration I will get to it

>quickly and report what I think, plus what a

>"blinded" listener thinks. On the other hand, how

>does one "form" those in a speaker?

>

>Did you get black tweeters or the cream-colored ones?

>

>A friend used to take big caps like that and plug them into .

>. . no, I think I'd better stop there and skip the liability.

>

>Bret

Bret Ebay with local pic up only one other bidder not as fast as me.

not in a hurry I have the LST's to work on first.

My AR 11s have the cream tweeters should I move them to the 10pi's the pi's have the silver mids as do the 11's. but the tweeters are black soft dome.

what I raelly need is two lst crossovers

Jim

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>I have the LST's to work on first<

My opinion is to work on the 10pi's first. It's easier, cheaper, and just as rewarding (in my opinion)as LSTs. Maybe not stacked LSTs - I'm not experienced with that.

Don't expect the 10pi's to sound like AR-11s. They really don't.

I hesitate to tell you to take the light tweeters out of your 11s, but I think I'd put the cream colored ones in the speakers I was going to listen-to. The cream colored ones, according to my ears, a European member's ears, my listening-buddy's ears, and reinforced in email I received from a respected forum member, have better top-top end extension.

But we are talking about a difference you'd be unlikely to notice if you didn't hear both, one right after the other. It's not like there is a noticable deficit with the black tweeters. The cream originals are just a little better in the opinion of several people who have heard both.

I promise I will do my very best to replace the big caps within a week from today.

Bret

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Hi Jim and Bret

I replaced my 2500 myF caps with the Jensen caps, I assume this is the cap Bret is talking about also. I by-passed it with a 68 myF as well as a 2.2 myF polypropylene caps to reduce ESR at higher frequences. At the same time I changed the resistor to a high quality Adiophile resistor from Duelund, and this combination gave a much better sound, especialy a more open midrange and a more airy high range. I think the low range got a bit more agile/dynamic, but I am not 100% certain about that.

I am much closer to AR-11 sound in my 10Pi after I have restored the X-over, but the 10Pi still has a bit more soft touch ro the music compared to the AR-11.

Enclosed a picture of the revised X-over, the long brown "pencil" in the front is the Duelund resistor.

BRgds Klaus

post-101646-1186992887.jpg

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>I assume this is the cap Bret is talking about also<

Both the cap and the person, but I was afraid to talk about you without your permission.

I am *really* surprised to hear you describe the difference in the upper frequencies. Honestly, being on the other side of the transformer and behind the resistor, and not attached to the mid and tweeter's + terminal, I would have thought that there would be little or no difference at all and it would be in the woofer's range.

So much for thinking, huh? Time to do, not think.

I'm almost bothered by your observation that your 10pi's sound more like your 11s than they did before. I've always thought the 10pi had it's own "signature," close to an LST's feel of wide-open reticence without all the placement problems.

Out of curiosity, what sort of monster amplifier have you got on your 10pi's? Surely a monster - right?

Bret

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Hi Bret

I am using a 30 year old (re-capped) Sansui AU 11000A amplifier (2x110 W RMS 8 Ohm), which suits the 10Pi extremely well. Used to have an AU 9900 (2x80 watt RMS), but that was not sufficient power for the 10Pi. I run my AR-11/LST's on a combo of a Luxman C12 pre and an NAD 208 power amp.

I think that the (in my taste) improved mid and highrange of my 10Pi, mainly can be contributed to the smaller bypass caps and the exchange of the resistor rather than the exchange of the giant cap. The effekt of the resistor replacement I am certain about, because I did an AB test with only one speaker upgraded. I am still working on my LST to get the midrange more open, I will replace the .5 Ohm resistor, and I also plan to test the effekt of a 10 Ohm by-pass resistor as it is used in both the 10Pi and LST-2.

And when I say that the 10Pi is closer to my 11, I am only talking about the tonal balance and especially the openess of voices and the precense of the instruments in the listenning room, they are more "out of the speaker". They are, however, still clearly different speakers.

BRgds Klaus

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Hello I picked up my AR 10pi's last night. hooked them up and man these sound great and they have not had the crossovers touched but the woofers were refoamed with the ring inverted not sure why. there way apart in numbers.

one is #1630 red swiches and fuse holder. soft dome black tweeter no foam.

the other is #9139 no fuse holder no red rubber over the switches black tweeter with rotted foam ring lable on the front

both have the silver mid what is the diff between these and black mids if any.

both have the brass AR 10pi

Jim

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They put the surrounds on upside-down? WHAT were they thinking. I have faith that you'll fix that.

There is no appreciable difference between the pink fiberglassed silver basket-ed midrange and the older one. The sonic differences a friend and I describe the same are so subtle, so hard to hear, and so unimportant that it may just be the ones we have and not every driver. And it could be our imagination. When differences get that small it's easy to imagine things.

The fuse-holdered version was built prior to May 1975. The tweeter in that one is almost certainly a replacement driver (for that cabinet) but still a relatively early, real, AR driver. The other one, with the foam, is a later unit. Unfortunately, I can't tell from your description if it is a later original, or a later replacement.

If it sounds like fingernails on a chalkboard it's a replacement. If it doesn't, odds are it's an original (or early replacement) from the era of the black-badged 10pi. OR, because I don't know these changes by their serial numbers, it *could* be that some brass badged speakers were shipped with the foam around the tweeter and you have the first one I've ever heard of.

If that foam label has a "circle" painted on it, I think that's a tweeter from the black-badged era and the only difference I'm aware of between the two tweeters is that one had the foam label with a circle painted on it and the other didn't. I think AR was trying to make the speaker look less cheap in an era when everyone else was using die-cast baskets - but those labels were just awful looking. There may have been some sonic benefit measured by lab equipment. I don't think I ever saw even a single one of those foams that was flat. I never heard a difference with or without.

I don't know why AR got rid of the fuses, unless the fuse ended-up not protecting the tweeter after-all. In that case, why go to the expense? Or maybe it is because the black ferrofuild filled tweeters were less prone to destruction.

The red plastic - someone's just pulled it off the switch handles. Shouldn't effect anything. But you can go to Radio Shack and buy some cheap mini-switches and use their caps over the 10pi switches.

The only other thing I think I "got" was that the black hole-filling "cups" that surround the switches are "gone" on one speaker and not the other? I have no idea where you are going to get replacements for those except off of another speaker.

Work's been stressful so I'm using my hobby as a wind-down tonight, Jim. I think I've just about wound-down.

I'll just say what I've said about 10pi's so many times before - Wait until you get 'em restored. I am looking forward to knowing if you think they sound as good, as well as unique, as I think they do. I won't get offended if you don't. . . I'll just send you my shipping address. ;-)

Bret

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>They put the surrounds on upside-down? WHAT were they

>thinking. I have faith that you'll fix that.

>

>There is no appreciable difference between the pink

>fiberglassed silver basket-ed midrange and the older one. The

>sonic differences a friend and I describe the same are so

>subtle, so hard to hear, and so unimportant that it may just

>be the ones we have and not every driver. And it could be our

>imagination. When differences get that small it's easy to

>imagine things.

>

>The fuse-holdered version was built prior to May 1975. The

>tweeter in that one is almost certainly a replacement driver

>(for that cabinet) but still a relatively early, real, AR

>driver. The other one, with the foam, is a later unit.

>Unfortunately, I can't tell from your description if it is a

>later original, or a later replacement.

>

>If it sounds like fingernails on a chalkboard it's a

>replacement. If it doesn't, odds are it's an original (or

>early replacement) from the era of the black-badged 10pi. OR,

>because I don't know these changes by their serial numbers, it

>*could* be that some brass badged speakers were shipped with

>the foam around the tweeter and you have the first one I've

>ever heard of.

>

>If that foam label has a "circle" painted on it, I

>think that's a tweeter from the black-badged era and the only

>difference I'm aware of between the two tweeters is that one

>had the foam label with a circle painted on it and the other

>didn't. I think AR was trying to make the speaker look less

>cheap in an era when everyone else was using die-cast baskets

>- but those labels were just awful looking. There may have

>been some sonic benefit measured by lab equipment. I don't

>think I ever saw even a single one of those foams that was

>flat. I never heard a difference with or without.

>

>I don't know why AR got rid of the fuses, unless the fuse

>ended-up not protecting the tweeter after-all. In that case,

>why go to the expense? Or maybe it is because the black

>ferrofuild filled tweeters were less prone to destruction.

>

>The red plastic - someone's just pulled it off the switch

>handles. Shouldn't effect anything. But you can go to Radio

>Shack and buy some cheap mini-switches and use their caps over

>the 10pi switches.

>

>The only other thing I think I "got" was that the

>black hole-filling "cups" that surround the switches

>are "gone" on one speaker and not the other? I

>have no idea where you are going to get replacements for those

>except off of another speaker.

>

>Work's been stressful so I'm using my hobby as a wind-down

>tonight, Jim. I think I've just about wound-down.

>

>I'll just say what I've said about 10pi's so many times before

>- Wait until you get 'em restored. I am looking forward to

>knowing if you think they sound as good, as well as unique, as

>I think they do. I won't get offended if you don't. . . I'll

>just send you my shipping address. ;-)

>

>Bret

Thank you Bret

First I will take these apart and start on the caps I went with solen in my LST so stay with them here also. I will find a nice matched pair of black tweeters for my 11's and take the cream tweeters out for the 10pi's the ones in my 11's are matched at 3.3 ohm each. next will be to find the floppy foam for the woofers these are not only backwords but to stiff.

sounds like you need to save those other 10pi's before they get boozak woofers put in them

these also came with some nice black walnut stands not the AR ones but they have spikes and pads for the speakers no extra cost. So I don't have to use my AR11's for stands:) maybe upside down on the 10pi's for stacked!!!! no would not do that to them

I wonder how close the crossover is to the LST

no not that iether or is it eather

take care and go save those other 10pi's from the parts express frankistien

I would be willing to trade him for some early AR3a's I have fully restored he can just plug and play play play stop.

good night

Jim

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another ? about these AR10pi's one has fiberglass stuffing the other acoustic stuff and it seams like about half compared to the fiberglass.

untill i get the correct foam on the woofers I will not be able to do a good comparison but from the first listen the fiberglass sounds like it has a better sounding bass.

Jim

I might just stuff it with the same amount of glasss and not worry that way they will be the same

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>another ? about these AR10pi's one has fiberglass stuffing

>the other acoustic stuff and it seams like about half compared

>to the fiberglass.

Jim:

I've not seen the ten-pi, but consider the AR-11 and AR-3a. They are similar but not identical. The eleven used 10 ounces of trilobal polyester whereas the three-a used 20 ounces of fiberglass. Of course there are some differences in the driver compliance and crossover C, but what you observe would not surprise me. One other query- did you find the stuffing installed uniformly or packed close to the woofer in the polyester-stuffed ten-pi cabinet?

Cheers,

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Jim:

Richard Lowe pointed out that the 10pi document in the Archives specifies 20 ounces of fiberglass uniformly distributed in the cabinet.

Does any 10pi owner out there know if your cabinet containing polyfill represented an AR factory change, or a "previous owner" change? This is always a problem with used equipment.

Cheers,

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>Jim:

>

>Richard Lowe pointed out that the 10pi document in the

>Archives specifies 20 ounces of fiberglass uniformly

>distributed in the cabinet.

>

>Does any 10pi owner out there know if your cabinet containing

>polyfill represented an AR factory change, or a "previous

>owner" change? This is always a problem with used

>equipment.

>

>Cheers,

Hello when i opened up the 10pi with the polyfill it looked factory layed in cut for wires. I took it out and there is no sign of glass at all in it also the fill was stuck in and around the crossover like AR would have done.

I think I will replace it with glass to match the other. also putting in the cream tweeters and a matched set of mids. its a shame the woofer foam was put on upside down I hate to pull it off it was a good job.

Jim

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>I think I will replace it with glass to match the other.<

Jim,

This is just another of those annoying things that seems to defy logic.

These speakers do not sound the same if you change the fiberglass to poly or vice-versa.

Doing some experimentation with Acousta-Stuf makes it very plain that even with "acoustic poly-fill" the cabinet does not have the same resonant frequency as with fiberglass UNLESS, and this is why I'm responding, AR was using something "fancy" that lead to the same Fc for the system.

IF, and I doubt it, but IF that's the case, it would be wonderful, marvelous, and otherwise GREAT! to know what that poly-fill IS.

How would you feel about sending that polyfill to someone (I'm thinking John O'Hanlon, but I might be willing to spend money on a woofer-tester and try this myself) and let's see what its acoustic properties are, exactly, as far as Fc is concerned.

The reason this might be good to know is that I find *one* aspect of using Acousta-Stuff superior (to my ear, not scientifically) to using fiberglass BUT you give-up some bass extension to get it. I don't want to describe it for fear of making someone else hear it, whether it is a real effect or not. I'd rather someone else reported.

Anyway, if shipping it to me, John, someone is more than you want to do, would you take a picture of it? Is it the multi-colored stuff that almost looks like something you'd stuff a sofa with, or is it ghostly white, or an even whiter shade of pale?

Bret

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