Original AR-11 crossover diagnostic help

[JKent]

1 hour ago, Mark Heija said:

Do I need to worry about the wood cradles creating an insulation that may help generate too much heat?  In soldering the two capacitors (100uf & 22uf) in parallel, is there a preference as to which might attach to which?

Nice work Mark!

No--no need to worry about the wood cradles. The caps don't heat up. My comment was about using hot melt glue, which may be harmful to the caps. 

I'm not sure I understand the 2nd question. To solder the caps in parallel you would twist the leads together at both ends. One end of the 22 twisted to one end of the 100 and the other end of the 22 twisted together with the other end of the 100. Picture below shows 2 caps in parallel.

Kent

[Mark Heija]

Thanks! Just wondered, 22 to ends of 100 or vice versa? Wouldn't seem to matter, but asked just in case.

[ar_pro]

I like your capacitor cradles - very innovative! The 9090DB "garage" also looks terrific.

Locating your speakers in corners is going to significantly impact how they sound. Also, having them up near the ceiling will certainly affect their presentation.

You might want to hold off on running the wires alongside your molding until you can test out how everything sounds with this format.

[JKent]

14 minutes ago, ar_pro said:

Locating your speakers in corners is going to significantly impact how they sound. Also, having them up near the ceiling will certainly affect their presentation.

1 hour ago, Mark Heija said:

1) Used a cool online Trig calculator to determine the exact downward angle for the speakers to face the cross room listening chairs (used string to create a right triangle). This angle was translated to wood platforms, later felt lined. 2) Built risers to get the speakers high enough to clear a door in one corner of the room, as well as placing them within the cove of the ceiling (good for sound dispersion?) and on swivel platforms for fine tuning.

ar_pro, sounds like Mark considered all that and designed things accordingly. The corners may have been the only or best place for the speakers. Maybe I'm over-sensitive because I had an audiophile offer unsolicited advice on how I should rearrange my speakers. There are lots of considerations including room size, space, other stuff in the room and the all-important WAF.

 

 

[ar_pro]

You're right Kent, I was just thinking about the corner arrangement providing a boosted LF presentation from the AR-11's 12-inch woofer.

Honestly, I don't think I've ever had a textbook stereo set-up, as there are always "lots of considerations". 

[Mark Heija]

Hey Folks, I've had to deal with odd speaker placement for the 40+ years my wife and I have lived in our pre-1906 earthquake Victorian apartment. The 13'x19' (redwood lathe and plaster walled) living room has 10' ceilings and bay windows at the narrow end (two big easy chairs for listening sit in the bay). Klipsch LaScalas sit just outside the bay facing inward towards each other... I call this a headphone placement. The sound is beautiful but for perfection the balance must be slightly adjusted to one side (only one chair gets the perfect). An SVS sub sits on floor on the other side of the room. My hope is that by adding the AR-11s opposite the bay seating, the correct volume from the direct facing speakers will compensate for the Klipsch balance issue? If having the ARs so close to the ceiling (on the last bit of available real estate) creates low end issues I have an old SAE parametric equalizer I can throw into the mix. I'm using a Sansui 9090DB to power the Klipsch and a Sansui 9090 for the AR's so I'll be shopping for some quality cables to tie them together. Really looking forward to melding the sound of my two favorite systems. 

On the AR refurbish front, I dove in and soldered the new capacitors into the first speaker today... things went well (a slight touch of the iron did get my attention pretty quick). Photo attached. I'll continue with updates -Mark

 

[Mark Heija]

Well, finished the reassembly of the speakers today. Did a quick test of the crossover recap and things sound like they're working (I was holding my breath!).

Only had a tiny 30w portable amp (Amazon around $25) and my trusty iPod (earlier version with a German sound card - or so I've been told). Loud ventilation in the shop didn't make for the best test space but up close everything seemed to be working fine.

I like my choice of stainless steel fasteners and the black felt to replace the deteriorating foam on the tweeters. Now to get them home... I've recruited a younger, athletic neighbor to help get them up the stairs of our building and will have him over to enjoy some fine sound and my famous (original Trader Vic's) Mai Tais once set up. I'll follow-up with how the system sounds in it's new home.

 

[JKent]

Those look great! No surprise after seeing your other woodworking.

Here's a question for some other members: Those mids don't look original. The 11s I refurbished had AR-3a style mids, as did the 11Bs. In fact, my AR-3a's have AR-11 mids, courtesy of Roy. Mark's look like the mids in my AR-91s. Or maybe more accurately, the AR-58s (I've only seen pictures). I think they're essentially similar. After all, the 11 and the 58s were essentially modern 3a's but did AR ever put those mids in the 11s?

Edited August 20, 2021 by JKent

[Mark Heija]

A note on the mid range drivers. I'm guessing in the 70's or early 80's I had my Sansui 9090 and the ARs at my Mom's house... I'm not really sure but I believe there was a selector not set for the desired source and she started by turning the volume up (way up!) and then tried the selector... to devastating effect. I did replace the mids (they looked like the ones in your photo) with what were then factory replacements?  the woofers were replaced in the 90's when the original foam fell apart and I didn't yet grasp the notion it was something I could have fixed (also with what I was told was a comparable driver). 

[Giorgio AR]

From what I see I seem to see the aftermarket woofer reproduced now and also sold on well-known auction sites, the mids should be 200044-0 and the tweeters probably 12000840 (spare parts for AR from the 90s).
I think everyone is curious about the sound judgment of these splendid AR11 specimens, by the way the cabinets have an incredible look, congratulations for your work on the wood.

[genek]

The mids definitely look like the 20044-0 for the AR-58s.

[AR55]

A few weeks ago, a friend of mine found a pair of AR9’s that, with one exception, were in excellent shape.  It had a damaged 1½” dome midrange.  I couldn’t locate an AR9/90 midrange for him, but I was able to find a nice used midrange from an AR-91.  The only difference between the AR9’s midrange and an AR-91’s midrange turned out to be the plastic used for the semi-horn.  While researching the AR library, I found that the dome midranges for the AR9, 90, 91, 92, 915 & 58s all appear to be functionally identical. 

I also found that the AR-11’s 1½” dome midrange shares the same voice coil and the same metal work with the AR9...58s midranges.  Before turning over the AR-91 midrange to my friend, I tried it out in one of my AR-11’s.  The sound, particularly off axis, is slightly different than the 11’s midrange.  I think the difference has more to do with the 91’s semi-horn then anything else.   Is the sound better?  I like my 11’s as they are, but I may be biased.

As an FYI – I also discovered that, much like the AR11's midrange, there looks to be little difference between the ¾” tweeter found in the AR-11B and the tweeters used in the AR9…58s.  That also carries through to the tweeters in the AR38b, 48b & 58b.

By the way, the speakers really look great!  I thought that I did a pretty good job with my restoration, but yours are definitely a step above.

[ar_pro]

Very nice work, Mark, they look terrific! I really like the cabinet finish - these speakers look as if they came from a Time Machine.

I do agree with AR55 regarding the AR-91 semi-horn, which tends to focus its output a bit. Like much of the competition at the time, AR may have been more interested in perceived imaging, and less in wide dispersion.

[Mark Heija]

Thanks. I've really become a fan of the Rubio Monocoat (in this case their Walnut, which give a natural matte finish) followed with their Maintenance Oil and light buff (adding a light sheen). ZERO VOCs too! I first became aware of their products when I watched a new oak countertop at a local Deli show no signs of ware over six months of daily use. I inquired with the owner about who did the fabrication/installation and the company told me about Rubio. Actually made for floors so it's extremely durable and with the added benefit over poly-finishes that with damage to the surface a simple sanding and re-coat blends in perfectly. Cons: a long dry time and pretty expensive... but someone could put a dripping beer mug on the top and not leave a ring (not that I'd let them😉

[DavidR]

7 hours ago, AR55 said:

The only difference between the AR9’s midrange and an AR-91’s midrange turned out to be the plastic used for the semi-horn. 

The AR9 and 90 used p/n 200028 UMR and the 91 uses p/n 200032 mid. The difference is the AR9/90 UMR has half the resonance of the 200032 mid. The AR9/90 UMR had ferrofluid on both sides of the vc. The 200032 can be used in place of the 200028 but not the other way around. The 200028 UMR just won't reach down to 700Hz IIRC that is required for the AR91. The 200044 came out when the 58 was introduced. It was mostly a cosmetic change. It was also used as an AR replacement driver from AR for the 200028 and 200032.

[genek]

The 1986 AR replacement parts list shows 200010-1 for the AR-19, 11, 3a and LST.

[RoyC]

2 hours ago, DavidR said:

The AR9 and 90 used p/n 200028 UMR and the 91 uses p/n 200032 mid. The difference is the AR9/90 UMR has half the resonance of the 200032 mid. The AR9/90 UMR had ferrofluid on both sides of the vc. The 200032 can be used in place of the 200028 but not the other way around. The 200028 UMR just won't reach down to 700Hz IIRC that is required for the AR91. The 200044 came out when the 58 was introduced. It was mostly a cosmetic change. It was also used as an AR replacement driver from AR for the 200028 and 200032.

I've dissected some of these mids along the way, and while I was not able to verify the ferrofluid situation, I did find the 200044 specimens to have no damping material under the dome. All others I've had apart (including AR-3a and AR-11 mids) did.

In a pinch I've used the 200028 mid as a replacement in a number of situations (including AR-3a, 11, and 91), and while there are some audible differences associated with the plastic ring (which, btw, is easily removable) and lack of metal grill with associated material, I would not say it does not do a reasonably satisfactory job around 700hz. In fact, the 3a and 11 both cross over a bit lower than that. The voice coils, domes, and suspensions of these mids are virtually identical going back to the AR-11.

Roy

[giovanni56]

10 hours ago, RoyC said:

Ho sezionato alcuni di questi medi lungo la strada e, sebbene non sia stato in grado di verificare la situazione del ferrofluido, ho riscontrato che i campioni 200044 non avevano materiale smorzante sotto la cupola. Tutti gli altri che ho avuto a parte (inclusi AR-3a e AR-11 medi) lo hanno fatto.

In un pizzico ho usato il 200028 mid come sostituto in una serie di situazioni (inclusi AR-3a, 11 e 91), e mentre ci sono alcune differenze udibili associate all'anello di plastica (che, tra l'altro, è facilmente rimovibile ) e mancanza di griglia metallica con materiale associato, non direi che non fa un lavoro ragionevolmente soddisfacente intorno ai 700hz. In effetti, il 3a e l'11 si incrociano entrambi un po' più in basso di quello. Le bobine vocali, le cupole e le sospensioni di questi medi sono praticamente identiche a partire dall'AR-11.

Roy

I measured at least thirty Ar 200010-1 midrange drivers and six Ar/TNG 121010-, the lowest Fs was 458Hz in the Ar/TNG, while in the Ar200010-1 550/580Hz, I never found a driver with Fs of 400Hz, while in the 200044 that I measured the Fs values varied from 685Hz to 730Hz, for this reason I consider the 200044 midrange not compatible as a substitute for the 200010-1 without having to modify the crossover filter for eventual use in the Ar11/10, Ar3a/Ar3a Improved.

[RoyC]

52 minutes ago, giovanni56 said:

I measured at least thirty Ar 200010-1 midrange drivers and six Ar/TNG 121010-, the lowest Fs was 458Hz in the Ar/TNG, while in the Ar200010-1 550/580Hz, I never found a driver with Fs of 400Hz, while in the 200044 that I measured the Fs values varied from 685Hz to 730Hz, for this reason I consider the 200044 midrange not compatible as a substitute for the 200010-1 without having to modify the crossover filter for eventual use in the Ar11/10, Ar3a/Ar3a Improved.

You must have quite a of collection of mids.

Fs goes down as the suspension wears, so it is not unusual for Fs to be lower in older drivers. This is true of woofers as well.

My primary point, however, is that as the supply of used replacement parts dwindles, few choices are readily available. In my experience these mids will work well enough for most people with the existing crossover. They are all mechanically identical, and the departure from the original sound will certainly be less, for example, than what I've been reading about your tweeter work.

Roy

[giovanni56]

43 minuti fa, RoyC ha detto:

Devi avere una bella collezione di medi.

Le F diminuiscono man mano che le sospensioni si usurano, quindi non è insolito che le F siano inferiori nei conducenti più anziani. Questo vale anche per i woofer.

Il mio punto principale, tuttavia, è che man mano che la fornitura di pezzi di ricambio, poche scelte sonomente disponibili. Nella mia esperienza, questi medi funzioneranno abbastanza bene per la maggior parte delle persone con il crossover esistente. Sono tutti meccanicamente identici e l'allontanamento dal suono originale sarà sicuramente minore, per esempio, di quello che ho letto sul tuo lavoro sui tweeter.

Roy

 

Every time I restore a speaker I measure all the drivers and, over the years, I have measured a lot of them, I have restored three pairs of Ar LSTs that have a total of 24 midrange drivers and many other Ars with the 200010-1, so thirty might be a few. It is true, as we age, the Fs of the drivers decreases but, if Ar claims 400 Hz for its new 200010-1 midrange, I would have expected that the ones I measured, being old, would have values lower than 400 Hz. In my opinion the mid 200044 is not compatible with Ar11 (and similar), with a cut between woofer and midrange at 525Hz because it has a too high Fs that is not mechanically controlled with the external damping wool held on the dome by the external grid as on the midrange 200010-1.

[giovanni56]

On 20/8/2021 at 05:47, Mark Heija said:

Bene, finito il rimontaggio degli altoparlanti oggi. Ho fatto un rapido test del riepilogo del crossover e le cose sembrano funzionare (stavo trattenendo il respiro!).

Aveva solo un piccolo amplificatore portatile da 30 W (Amazon circa $ 25) e il mio fidato iPod (versione precedente con una scheda audio tedesca - o almeno così mi è stato detto). La forte ventilazione nel negozio non era il miglior spazio di prova, ma da vicino tutto sembrava funzionare bene.

Mi piace la mia scelta di elementi di fissaggio in acciaio inossidabile e il feltro nero per sostituire la schiuma deteriorata sui tweeter. Ora per riportarli a casa... ho reclutato un vicino più giovane e atletico per aiutarli a salire le scale del nostro edificio e lo inviterò a godersi un bel suono e il mio famoso (originale Trader Vic's) Mai Tais una volta installato . Farò seguito a come suona il sistema nella sua nuova casa.

 

Very nice, congratulations!

[RoyC]

12 hours ago, giovanni56 said:

Every time I restore a speaker I measure all the drivers and, over the years, I have measured a lot of them, I have restored three pairs of Ar LSTs that have a total of 24 midrange drivers and many other Ars with the 200010-1, so thirty might be a few. It is true, as we age, the Fs of the drivers decreases but, if Ar claims 400 Hz for its new 200010-1 midrange, I would have expected that the ones I measured, being old, would have values lower than 400 Hz. In my opinion the mid 200044 is not compatible with Ar11 (and similar), with a cut between woofer and midrange at 525Hz because it has a too high Fs that is not mechanically controlled with the external damping wool held on the dome by the external grid as on the midrange 200010-1.

OK, I'll see your LST's and raise you three or four more pairs. 😉...but I believe you are still missing my point. Mark will have a nice sounding pair of AR-11's in my experience. I recommend simply removing the plastic rings from the mids. He can always shop for other mids if he wishes...or, better yet, you can send him a pair of yours.

By the way, Levinson's first iteration of the Cello Amati was essentially an LST clone equipped with 80's era AR mids. I repaired 2 pairs of Amati's some years ago, and had a chance to inspect the mids closely. They were nothing more than AR-9xx type mids without the glued-on ring. The link below contains a photo.

https://www.canuckaudiomart.com/details/649673716-marklevsion-cello-amati-speaker-single/images/2962960/

Roy

 

 

[Giorgio AR]

18 hours ago, giovanni56 said:

the lowest Fs was 458Hz in the Ar/TNG, while in the Ar200010-1 550/580Hz

Rereading I found your measurement on the AR / TNG mid, it is further news to learn more about the components of my AR10TT Replica!
You also have the measurements of the AR / TNG 1210003-1A woofers and tweeters (I have to remove it for identification n °)

As soon as it is removed, I insert photos of the back.

[giovanni56]

6 hours ago, RoyC said:

OK, vedrò i tuoi LST e rilancerò altre tre o quattro coppie. 😉 ...ma credo che tu manchi ancora il mio punto. Secondo la mia esperienza, Mark avrà un bel paio di AR-11 dal suono gradevole . Consiglio di rimuovere semplicemente gli anelli di plastica dai medi. Può sempre acquistare altri medi se lo desidera... o, meglio ancora, puoi inviargli un paio dei tuoi.

A proposito, la prima iterazione di Levinson del Cello Amati era essenzialmente un clone LST dotato di medi AR dell'era degli anni '80. Alcuni anni fa ho riparato 2 paia di Amati e ho avuto la possibilità di ispezionare da vicino i medi. Non erano altro che medi di tipo AR-9xx senza l'anello incollato. Il link sottostante contiene una foto.

https://www.canuckaudiomart.com/details/649673716-marklevsion-cello-amati-speaker-single/images/2962960/

Roy

 

 

This is the last pair of Ar LST's I restored about a month ago. The owner's name is Marco, he lives in Pisa. He brought them to my home in Ravenna as several other owners of Ar speakers have done over the years to entrust me with the restoration or maintenance, so I had the opportunity to test and measure several drivers. I own a pair of 200010-1 midrange speakers that I jealously guard as a spare and do not sell. I joined this group because since 1970, I have been an Ar enthusiast. I joined because I like to compare technically, with due respect and education to all, no one excluded. I'm not a salesman and it's not my habit to tell lies. What I have stated in my previous posts on this thread is due to technical considerations, but I respect your opinion that comes from your decades of experience in the field. This is not a competition between you and me to see who can piss the farthest. Best Regards Giovanni

[giovanni56]

1 hour ago, Giorgio AR said:

Rileggendo ho trovato la tua misura sull'AR/TNG mid, è un'ulteriore novità per saperne di più sui componenti della mia Replica AR10TT!
Hai anche le misure dei woofer e tweeter AR/TNG 121003-1A (devo rimuoverlo per identificazione n°)

Appena tolto inserisco foto del retro.

Hi Giorgio, yes, I have the measurements of the woofer and tweeter Ar/TNG, as soon as I recover them I'll send them to you on Whattsapp; given the treatment, I think I won't post anything here anymore