fedeleluigi
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Posts posted by fedeleluigi
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7 hours ago, meta_noia_fot said:
Before I refoam these, does anyone know if this midrange cone is correct?
Yes, the cone is correct!
You can see other identical pictures of the Tonegen AR9LSI lower midrange on this thread (last images):
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2 hours ago, baffled_loudspeaker said:
Yes! But why?!
Hello,
Actually there is no extra inductor in the AR-90 because the AR-9 also has it!
The AR-9 crossover schematic in the library is wrong. In my post linked below you can find the correct schematic of the AR-9 redrawn by me.
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11 hours ago, Markolone said:
About the first suggestion, to exchange the drivers, I can do it but originally the two speakers had a similar sound.
It may be that before the capacitor replacement you didn't pay much attention to the sonic differences between the two speakers.
11 hours ago, Markolone said:I changed the type only for two NPE (one on the tweeter and one on the mid);
Using the 8.2uf polypropylene cap in parallel with the midrange may have altered the damping and therefore the frequency response around the crossover frequency (with the tweeter).
On 5/1/2023 at 2:49 PM, Markolone said:After several listens I'm tempted to say it sounded better before
Without accurate measurements of both the capacitors you used and the recapped speaker it's hard to tell if the degradation you hear compared to the original speaker is real or not.
11 hours ago, Markolone said:The last (funny) hypothesis should be the following: because some capacitor value is more close to the original project, it could be that 40 years ago they sounded like this. But my ear had became accustomed to the old sound.
In my experience frankly it has never happened to me that replacing the old capacitors in AR speakers made the sound worse. There is generally an improvement especially when the old capacitors are out of specification.
Just follow the simple rules mentioned by Ken Kentor in the thread I linked.
Personally, for AR speakers, I only use bipolar audio electrolytic capacitors (usually Bennic or M.D.L.) from reliable sources (unfortunately there are many fakes). I always measure them to select them. I never use the small bypass capacitors.
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On 5/1/2023 at 2:49 PM, Markolone said:
There is a perceptible difference between the two speakers
Hello Marklone,
To be more scientifically sure of this difference you should swap all drivers from one speaker to another. Actually the difference could depend more on some differences in the drivers (they are around 40 years old) than on those of the crossovers.
On 5/1/2023 at 2:49 PM, Markolone said:I tried to switch the position of the speakers thinking of a difference due to the environment, but it was not that.
You did well. In reality during the comparison the two speakers should "ideally" be in the same place in the room (as even the same speaker in two different places in the room will sound differently).
Therefore, when making the comparison, I suggest you place the two speakers at least next to each other and swap their positions from time to time. Obviously the musical signal must be the same for the two loudspeakers and not the right/left one of a stereo signal. If you don't have the mono option on your amplifier you can use an RCA splitter on your source (CD player, etc) and use only the right (or only the left) signal for both speakers
On 5/1/2023 at 2:49 PM, Markolone said:After several listens I'm tempted to say it sounded better before.
That wouldn't surprise me!
The ESR of the capacitors may affect not only the attenuation of the driver and the crossover point (when placed in series) but also the damping operated by the crossover filter (when placed in parallel). In other words, the use of capacitors with ESR different from the original ones can compromise the target response of the speaker.
Ken Kentor (kkentor) and David Smith (speaker dave), two leading speaker designers writing on this forum have pointed this out on different occasions in this and other forums. Read for example what Ken Kentor says in the thread below about replacing capacitors.
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On 2/4/2022 at 11:39 PM, RoyC said:
Sorry, fedeleluigi, There are no documents to share. The information was based on phone conversations with AR (then in Benicia, CA) and AB Tech in late 1993.
Roy, thanks very much for replying and clarifying;
On 2/4/2022 at 11:39 PM, RoyC said:There were two versions of the mid available at that time. One had a screen and one did not, and I was told they were internally identical. The mid with the screen looked like the one used in the AR-3a Limited. The one without the screen had no plastic ring, and looked like the one used in the earlier Cello Amati.
As far as I know, after stopping in-house production of its 1-1/2 in. midrange (p.n. 200010-1), AR supplied a similar unit manufactured by Tonegen as a replacement part. Until circa 1990/early-1990s the part number of the Tonegen midrange was 1210010-1. Then the part number changed to 1210010-1A and this number was kept until the end of the production (around the mid 90's) of the drivers with screen and fiberglass pad in front of the fabric dome.
The Tonegen 1210010-1 and 1210010-1A midranges were aesthetically practically identical and frankly I don't know what was the real reason for the change of the part number. BTW, in the same period also the Tonegen 12" woofer used as replacement part for AR-3a, LST, 10 Pi, 9, 9LS etc. changed its part number from 1-2100030B or 1210003-0B to 1210003-2A.
As said, both of 1210010-1 and 1210010-1A midranges had the screen and fiberglass pad in front of the fabric dome like the original AR 200010-1 midrange.
Later, before its final closure (which occurred around the mid-90s), Tonegen produced the latest 1-1/2 inch midrange (p.n. 1210010-3A). It was used both by AR as a spare part and by CELLO for its latest loudspeakers using Tonegen components (CELLO switched to Dynaudio drivers when Tonegen closed down). As said, the part number of this latest 1-1/2 inch midrange made by Tonegen was 1210010-3A. It was basically the same midrange as before but lacked the distinctive screen and fiberglass pad of the original AR 200010-1 midrange.
So, it was the latest CELLO Amati, Stradivari Master and Grand Master and not the early ones to use the Tonegen midranges without screens (1210010-3A). The last picture shows this.
Mark Levinson (who had founded CELLO Ltd. in 1984), one of the most skilled marketing strategists in the HI-End world, said that these latest AR midranges were an evolution and sounded better than their predecessors. Note that at the time no one (except industry operators) was aware of Tonegen and that the drivers used in these very expensive and made in USA loudspeakers were actually manufactured in the East by Tonegen itself.
Personally, I think Tonegen was actually scraping the bottom of the barrel and had no more screens available for that type of midrange as they were closing down. In other words, as far as I know, the 1210010-3A was the midrange of the last batches that Tonegen supplied to AR (and CELLO) through AB Tech and that was used while stocks lasted.
Obviously some vendors of AR replacement parts found themselves having both the old 1210010-1A and the new 1210010-3A in stock for some time. What I do know for sure is that, at some point, the official Italian distributor of AR (Arcona) stopped supplying the 1210010-1A midrange and started to supply only and exclusively the 1210010-3A midrange while stocks lasted.
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A young Mark Levinson with the early Cello Stradivari Grand Master using the Tonegen 1210010-1 or 1210010-1A midranges. Note the midrange screens and fiberglass pads.
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On 1/26/2022 at 5:15 PM, teknofossil said:
I don't know if this will be useful to anyone.
Yes, it will. Measurements, if properly carried out, are always useful and, above all, objective.
Thank you very much
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On 1/27/2022 at 5:11 AM, RoyC said:
Later replacement guidance from AR in the early 90's actually recommended a universal Tonegen replacement for all models.
Roy, would you mind sharing these documents with the community? I do think that every member of this forum will thank you. Me first!
Thank you
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In order to make things easier I attached Rlowe's files to this post. The 1027 file extention has been corrected.
1026.pdf 1027.pdf AR10pi-CircuitNotes Version 1.1 Sep2014 (1).pdf
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For those who want to restore the AR-10 Pi crossover, Rlowe's files can be very useful. He did an excellent work with the last update (AR10pi-CircuitNotes Version 1.1 Sep2014) and the 1026.pdf and 1027.txt files. You can download them from the old thread “ AR10Pi crossover schematics” : https://community.classicspeakerpages.net/topic/1520-ar10pi-crossover-schematics/?do=findComment&comment=58409
PS: Note that there is an error in the file extension of the 1027.txt file. After downloading it, in order to open it you need to change its extension from .txt to .pdf.
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On 12/21/2021 at 6:30 PM, genek said:
When I bought my speakers in 1975, the dealer had both AR3 and AR-3a in his listening room. With level controls at the same settings, the 3a definitely had stronger mids and highs, though it was easy enough to turn them down a bit and make them sound almost identical to the 3 (we didn't try turning the 3 up to see if it would sound like the 3a, but it wouldn't surprise me if that would have worked just as well).
The biggest difference I noticed between 3 and 3a was that the 3a sounded a bit "smoother" in the upper bass/lower midrange (at the time, I did not know that the 3a crossed from LF to MR at a lower frequency).
That's my recollection of 3/3a comparison when both were new. I've never had the opportunity to do the same comparison with 50-year old units.
👍This is exactly what the magazines of the time (I posted previously) wrote!
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On 12/21/2021 at 5:46 PM, frankmarsi said:
I'm glad that you've posted evidence of actual tests reports but, I fear it may all fall on deaf-ears.
Thanks a lot Frank,
Since CSP is the most important source of information in the world about Acoustic Research, whenever possible, I try to point out inaccuracies and errors. Unfortunately there are now many and unfortunately I don't have the time to intervene for each of them.
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On 11/24/2020 at 8:59 PM, Sonnar said:
The real AR 3 frequency response is very different from 3a , quite opposite . Midrange is very quiet , understated , while AR 3a's midranges are very strong : however , while AR 3a's tweeter has a gentle roll-off , AR 3's tweeter has a rising response , exceptional sparkling highs never harsh, quite electrostatic .
I think original Villchur 's AR are very different from AR of Teledyne era.
Dear Adriano @Sonnar, I'm sorry for your "unscientific" beliefs but after more than one year I can scientifically prove that your supposed assumptions about the differences in the on-axis frequency responses between the AR-3 and AR-3a etc. are completely wrong.
All this because, in one of my recent electro-acoustic books I've found (much to my surprise) the on-axis frequency responses of both the AR-3 and the AR-3a. But perhaps most important is that the measurements were performed by the same engineer (one of the best electro-acoustic engineers known) in an anechoic chamber. So these frequency response measurements can be absolutely compared (apples with apples as I told you in my previous posts).
By examining them carefully, it is clear that the on-axis frequency responses are very very similar for both speakers.
Both have an identical frequency response pattern with a similar (practically identical) high frequency roll off. Again, the on-axis frequency responses are really very very similar, indeed, taking into account the manufacturing tolerances, they could easily belong to two different speakers of the same type.
The on-axis response of the AR-3a measured by Allison-Berkovitz in an anechoic chamber and that of the AR-3a measured by the author and reported in his book are superimposed. They are similar but not perfectly identical. The differences that can be observed between the two AR-3as are perfectly comparable to those that can be observed between the frequency responses of the AR-3 and the AR-3a.
Room response is not reported. However, for reasons of physics, due to the different dispersion of the mid-range and high-range drivers (greater in those of the AR-3a) the power response benefits the AR-3a in in a reverberant room. In other words, when these speakers were new, the AR-3a had more "sparkling highs" and more open sound than the AR-3 in a common listening room.
As the book is recent, for copyright reasons, I cannot post the graphics here. If you are interested in, please contact me and I will phoytocopy the image and send it by mail to you privately.
Luigi
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On 12/9/2021 at 1:18 PM, fedeleluigi said:
In any case its inner diameter (9.80 in = 248,9 mm)... did not change.
The above statement that I posted is incorrect.
I found a file of mine with the measurements of the masonite ring detected during some of my repairs. Here is a table with the measurements I found. The inner diameter I measured did change over the years. Obviously I did not measure 1,000 woofers to make statistics but I do think that the inner diameter changed after April 1977.
I specify that as regards the measurement of the thickness of the masonite ring, 3 mm refer to the measure in mm shown in the AR drawing I posted some days ago (see above). Actually 1/8 in (shown in the AR drawing) are 3.175 mm and not 3 mm as shown in the same drawing, but I doubt 0.175 mm would change anything.
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On 12/9/2021 at 3:52 PM, giovanni56 said:
I have made now a measure of the external diameter of the masonite ring on a woofer 200003 with black basket and it is 280mm so the 263mm indicated in the Ar drawing does not convince me, maybe the drawing refers to the masonite ring of the 200003-1.
The measurements of AR drawing I posted refer to the masonite ring for the 200003 woofers produced after April 1977, i.e. those used in the AR-10 Pi MKII and AR-11 MKII. Anyway you can see the previous measurement of the Outer Diameter (O.D.) in the "Revisions" of that drawing. See Revision E where they say that the O.D. was 11" i.e. 279,4 mm which is a similar measurement to the one you took. Unfortunately the inner diameter of the masonite ring for the previous older woofers is not reported in the revisions.
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On 12/8/2021 at 1:07 AM, frankmarsi said:
I joined in Nov. 2004 and my archive only shows from Feb. 2006
Others have posts from 2004 on yet, mine are gone.
The exact same thing happens to me. I've been writing on this forum since April 2002 but if I see my activity it only shows from 2016 as you can see in the picture below!
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On 12/7/2021 at 11:13 PM, genek said:How many years ago?
As in my posts I sometimes put some links to old or very old threads I could find some of my very old posts. For example you can see the picture and thread link of one of them below. It was written in 2003. So, why my old posts do not appear in my activity any longer contrary to a few months ago when they did appear? In other words if my very old posts do still exist, why my activity only shows posts from 2016?
Picture of one of my posts written in 2003:
its thread link:
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On 12/7/2021 at 9:06 AM, Giorgio AR said:
I want to find the AR drawings of the masonite ring of the 200003 woofer,
Here's the AR drawing of the masonite ring for the 200003 woofer manufactured after April 1977 (probably a few months later).
With the introduction of the AR-10 Pi MKII and AR-11 MkII the 200003 woofer had some changes and also the masonite ring. In any case its inner diameter (9.80 in = 248,9 mm) and thickness (1/8 in = 3.175 mm) did not change.
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On 10/1/2021 at 3:12 PM, Pete B said:
@fedeleluigi There are several posts in this thread with the AR-9 xo schematic, is that one redrawn,
and the one you are looking for an original from AR? I can look on my 10 year old computer where I
probably downloaded it. On the other hand if the redrawn one is easier to read I might have just
kept that one.
Thank you Pete,
at the moment I only miss the original AR drawing of the AR-9 crossover schematic. But, probably, it has never been posted on CSP. However, If you have it please post it.
Thank you
I corrected the AR-9 schematic present in the CSP library:
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In 1977 a new 12" ferrite woofer was introduced. It had some differences from its predecessors and I do think that it was on that occasion that a new foam surround was also introduced. It measured about 5/8" (exactly 15.8496 mm) as you can easily calculate from the dimensions shown in the following AR drawing. I think that is why the restoring AR-3a document reports 5/8" for the foam surround.
Click on the image and open it in a new tab to enlarge it.
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On 10/15/2021 at 4:26 PM, giovanni56 said:
From the attached Ar drawing the curved edge of the foam is 0.72" or 18.299mm.
Hi Giovanni, I posted that AR Drawing of the 12" Woofer Cone\Skiver Assembly in a thread where we discussed about the date of the introduction of the 12" ferrite woofer. So you can see that I highlighted the date 1 July 1969 in that drawing .
Note that the last revision (revision F)of that drawing is dated 23 August 1976.
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Today, thanks to web.archive.org I was able to find some AR engineering drawings which unfortunately are neither present in the CSP AR-Drawings nor in other pages of this site but were present in some pages of the old site (Arsenal.net).
For those who want to download them (as long as they are downloadable) the link is the following: http://web.archive.org/web/20040604022548/http://www.arsenal.net/speakers/ar/ar.htm
So, on web.archive.org I could find the original drawing of the AR-9 crossover assembly, the AR-90 crossover schematic (it has a much better resolution than that of the new site) and other interesting files. Unfortunately, I could not find the original technical drawing of the AR-9 crossover schematic.
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If any member has the engineering drawings (possibly not resized) of the AR9-90 schematic and crossover assembly, please post them. If the files are too large to be embedded here, please post me a PM.
Unfortunately, it seems that they are not present in the AR Drawings except that of the AR90 crossover assembly.
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On 12/4/2020 at 4:21 AM, r_laski said:
I'm posting this AR9 crossover schematic and picture to show there is a second 1.37mH (6) coil in the Upper MidRange (UMR). It is the one to the right in the picture. One (outside) wire is connected to the 24uF cap and 0.2mH coil. The other (inside) wire is connected to the upper black (-) binding post. The other 1.37mH (6) coil is on the lower left corner. One wire (outside) is connected to the 0.2mH coil, orange wire to UMR (+), and 8uF cap. The other wire (inside) is connected to the 6 Ohm resistor, as shown in the schematic (resistor not in the picture).
In 2009 mluong303 wrote about the same mistake on the CSP schematic and the correction that you reported.
Contrary to AR9 schematic in the CSP library, the AR90 schematic (original engineering drawing) is correct concerning this point. It also has the 8uF capacitor instead of the 6uF (on the CSP schematic) in parallel with the upper midrange. On the AR90, the HR, UMR and LMR are connected out of phase with respect to the woofers.
Here a little inconsistency in the original AR90 schematic is reported (with respect to the crossover assembly).
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Hi Jay,
Ken Kizer (aka dxho @dxho ) did an excellent job and I take this opportunity to thank him:
https://community.classicspeakerpages.net/topic/13990-access-to-ar-drawings/?do=findComment&comment=136564
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13 hours ago, Jay said:
Jay, these pictures you posted are the pictures of a Tonegen 1210040-xx woofer used as replacement part for the 200004-2 original woofer. The Tonegen part # is printed under the 200004-2 label. Contrary to what the label reports, I don't think this woofer was ever built in the USA. Note the big resistor.
Steve Feinstein has passed away.
in News
Posted
Dear Ella,
I am deeply saddened by the loss of your father. Unfortunately I never had the opportunity to met him in person but only through The Classic Speaker Pages since the early 2000s. As others have said, his contribution to this forum has been invaluable and I will personally miss his presence greatly. Thank you very much for letting us know.
My deepest condolences to you and your entire family.
Luigi Fedele