danajohnhill.org | Hard Times Come Again No More

As I wrote recently, I am lately the proud and lucky owner of a pair of vintage AR-3a loudspeakers.  Acoustic Research manufactured many models of speakers from the 1950s on, but the 3a is considered their finest achievement, and one of the best loudspeakers ever made in America.  But it was also very expensive (equal to about $3,200 in 2008 dollars), and that, coupled with some quirky technical issues (which I will describe), mean that the AR-3a is seldom encountered in the used market in especially good condition.  Mine are virtually pristine.

Before I brought these speakers home last month, I knew practically nothing about them.  But, a quick internet search took me to a wonderful website called The Classic Speaker Pages, and there I found the document that became my bible as I undertook the project of bringing my AR-3as back to life: “Restoring the AR-3a”.  The Classic Speaker Pages also have a discussion forum devoted to Acoustic Research loudspeakers, and several members of the board have extensive experience with the AR-3a going back decades.  They provided valuable assistance as I remedied the little technical issues that, understandably, affect a forty-year-old speaker.

What goes wrong with the AR-3a over time?  A couple of things.  The first is something that goes wrong with all old loudspeakers: woofer surrounds deteriorate.  Most speakers use foam to connect the cones to the baskets, and over time that foam disintegrates and crumbles away.  The early AR-3a used cloth surrounds, and while the cloth itself will stay perfect, the material used to keep that cloth acoustically sealed fails over time.  Acoustic suspension speakers like the AR-3a rely on a practically airtight cabinet, and when the material that seals the cloth surrounds deteriorates, the cones move too freely.  In the bass-rich AR-3a, too much movement in the woofer can destroy the voice coil.  Replacements for AR-3a drivers are no longer made.

Meanwhile, inside the AR-3a cabinet, two issues almost always need addressing.  First, the forty-year-old capacitors have drifted from their original values, and need replacing.  That’s no big deal, since capacitors are inexpensive and easy to find.  The second problem that plagues many Acoustic Research loudspeakers is corrosion in the potentiometers.  The 3a has one potentiometer each for the mid-range driver and the tweeter.  They are fairly simple contraptions, but invariably have become oxidized or corroded, and that means they often no longer make electrical contact.

So, bad capacitors and bad potentiometers mean that many old AR-3a loudspeakers no longer sound the way they should.  And, when people play them loudly without making sure the cloth surrounds are still sealed, they risk serious damage.  I was extremely lucky that my 3as had no damage whatsoever.  Even the walnut cabinets are perfect, which is almost unheard of.

Following directions in the “Restoring the AR-3a” guide, I quite easily re-coated the cloth surrounds on the woofer with Permatex Hi-Tack Gasket Sealant that I readily found at the auto parts store.  A very thin coat over the surrounds and dust caps–which are also cloth–sealed everything very well.

With the woofers out, I removed the fiberglass that fills every AR-3a cabinet.  The crossover network inside seems very complicated at first glance, but after staring at the schematic it began to make more sense.  I was fortunate that these cabinets had never been opened, and all the wiring matched the schematic perfectly.

Not wanting to get in over my head, I took the potentiometers out, cleaned them, and reinstalled them one at a time.  One of the four was like new.  The rest showed a good amount of oxidation.  My Dremel tool took care of that.  I re-soldered each potentiometer as I put it back in, and avoided needless confusion that way.

The original capacitors in the AR-3a look nothing like the capacitors made today.  One large box inside the cabinet houses a 50- and 150 micro-farad capacitor.  A separate small box contains the 6 micro-farad capacitor.   I simply cut out the old capacitors and soldered in the new ones.  It is amazing how much smaller modern capacitors are than the ones installed in older speakers.

Having cleaned the potentiometers and replaced the capacitors in each cabinet, I then replaced the grey putty that encircles the woofer opening, providing an acoustic seal.  The original was still somewhat malleable, but I didn’t trust it to do the job, and new putty is cheap.  I ordered it from an eBay seller that specialized in Acoustic Research restoration projects.  I placed the heavy woofers back in each cabinet, tightened the screws, then re-installed the grilles.  I was ready to test the speakers.

I carried them into the living room, hooked them up to my stereo, and played the music I always use on these sorts of occasions, Trevor Pinnock’s recording of the Brandenburg Concerto No. 2.  It is complex music that isn’t too bottom-heavy, but has plenty of texture.  I set the volume to a low level and pressed play.  I put my ear to each driver on the right speaker, and was thrilled to hear sound from each.  I had to tweak the potentiometers on the back of the cabinet: the AR-3a has plenty of bottom end; the mid-range driver is strong, too, and needs to be turned down a bit; and the tweeter is bright and clear, but needs to have its pot turned wide open.  Satisfied, I put the grille back on and moved over to the left speaker.  The woofer and tweeter seemed perfect, but the mid-range driver produced no sound.  I was crushed.

My first thought, of course, was that the potentiometer was still a bit dirty, so I rotated it, hoping to find the sweet spot.  No luck.  So I carried the speaker to the back room and began the arduous process of opening it up again.  The guts seemed just right.  The right colored wires connected to the right components, just like the schematic.  I inspected all my solder spots, and they seemed to be fine, too.  But maybe one was a little loose, so I did it over, re-stuffed the cabinet, re-sealed the woofer, and carried it back out to the living room for another test.  (It took me several days to find the time to do all this.)  Still, the mid-range driver produced no sound.  I began to worry.

Of all the things that can go wrong with the AR-3a, the worst, of course, is a bad driver.  They don’t make accurate replacements for the originals, and when you can find authentic ones on eBay, they sell for hundreds of dollars.  That seems like a lot of money for a one-and-a-half-inch dome speaker.  If I did have to replace the driver it wouldn’t be the end of the world, since I paid nothing for the speakers, and even putting a few hundred dollars into them would still be well worth the expense.  But I certainly hoped that it was almost anything besides the driver.

I didn’t have a multi-meter to test the driver, but the engineer at work loaned me a small tone generator used to test speakers.  You press a button corresponding to the frequency you want to generate, hook the leads to the speaker and see if makes a sound.  I was dreading the result, but to my great relief, the mid-range driver emitted a 15kHz tone, which told me the driver was fine, and the problem was somewhere else.  I went to Home Depot the next day and bought a small multi-meter, then began the process of testing each component inside for connectivity.

The potentiometer was still the most likely source of the problem, but the meter showed that it functioned perfectly.  The wire from the potentiometer to the speaker terminals on the front of the cabinet were also fine.  So the problem lay somewhere before the pot.  My multi-meter doesn’t work on capacitors, but I doubted that a brand new cap would be a dud.  I was stuck.

I turned to the AR Forum on The Classic Speaker Pages, and posted a message describing my malady.  A short time later somebody posted a list of potential problems, still convinced that it was a wiring error.  One thing mentioned in passing, though, caught my attention, because it related to something I did inside the cabinet.  When I removed the potentiometer for the tweeter, I un-soldered all the wires leading to it, then re-soldered them.  But when I removed the pot for the mid-range, I cut the last quarter inch of wire, re-stripped, and soldered the pot back in.  A long coil of seemingly bare copper wire leads to the mid-range pot.  (You can see it in the center of the picture here.)  I just soldered that where it was supposed to go.  It never occurred to me that that copper wire had a thin but tough lacquer coating.  Having cut the last bit of that copper wire, I had cut out the portion with the coating removed and re-soldered a coated portion.  That was the cause of my trouble.  I corrected my mistake, closed the cabinet, hooked up the speaker, and repeated my listening test with felicitous results.

The AR-3a sounds amazing.  The bass is deep and solid, the mids are stunningly lifelike, and the treble sparkles.  Listening to Bringing it All Back Home, I was stunned by “Mr. Tambourine Man”.  The acoustic guitar seemed completely natural, so that if I closed my eyes, I couldn’t tell that there wasn’t some living person playing an acoustic guitar in my living room.  Meanwhile, new details are being revealed in songs I have known for a long time.

I am indescribably lucky. Huzzah, AR-3a!

Filed under: Music, Technology on March 5th, 2010 | No Comments »

Fifty years ago, if you had asked any American kid what the future would look like, he probably would have told you we’d have flying cars, robot butlers, jet packs, and so on.  He wouldn’t have predicted we’d all be fatter than ever, sitting in bumper-to-bumper traffic, driving cars that look much less cool than the ones he could see cruising on his shiny new, wide-open Interstate.  None of that boy’s predictions may have come to pass, but I experienced the future last night, and it was amazing.

We went to Best Buy last Saturday and bought a Blu-ray disc player.  I had seen one at a friend’s house last year, and the picture was incredible.  But I expected it to be.  Since the introduction of the DVD player, video quality has been steadily improving.  HDTV, of course, has been the greatest leap forward.  But the Blu-ray player is much more than high-definition video.  It’s Netflix.

I must be the last of my friends to use Netflix, an online video store that sends DVDs to members through the mail, which they then watch and return.  That process is fairly low-tech, and never struck me as the most convenient way to watch movies, though I had to admire Netflix’s selection.

Recently, visiting friends, I have seen that Netflix now offers streaming video, which can be accessed via fancy game consoles or a Blu-ray player.  Harris and Kat, and Ryan and Karla showed us how they could select from a seemingly unlimited number of Netflix films to watch instantly on their TVs through internet streaming.  My prognosticating skills are apparently limited, because I never thought streaming video was the future.  That is, I thought slow internet connections and limited hard-drive space were significant obstacles.  Who, I wondered, would spend hours downloading a movie, which will take up a ton of space on his or her computer, and which he or she will have to watch on a tiny computer screen?  That’s not how it works, it turns out.

On Monday morning I hooked up our new Blu-ray player, moved around some wires so I could connect it to the cable modem, and then signed up for Netflix.  Last night we experienced the magic.  We went to the Netflix website, selected the exact movie Miriam wanted to see at that moment, added it to our “instant” cue.  Then, magically, that title appeared on our TV screen.  I pressed play, the Blu-ray player spent thirty seconds or less downloading the movie–or at least it began downloading the movie–then the film began.  The picture was widescreen, looked as good as a DVD, sounded as good, too, and played flawlessly without any skips or blips for the entire duration of the film.  I could barely believe it.  Miriam and I high-fived each other.

So, now there are countless movies and TV shows that we have ready to watch whenever we sit down in front of the television.  Plus, we can still get physical DVDs and Blu-ray discs in the mail.  I’m expecting Parsifal today.

We’re living in the future!  What does it cost?  Less than nine dollars a month.  Since we canceled the premium channels on our cable, were saving money.  Huzzah!

Filed under: Film, Friends, Musings, Technology on February 24th, 2010 | No Comments »

Instances of genuine serendipity are rare.  Perhaps once or twice in life do we experience some unexpected and profound bit of material gain.  Out of nowhere, someone will offer you a gift, and it will be exactly what you wanted, but could never have come about on your own.  That just happened to me.

I listen to a lot of music, and for years I have dreamed of owning a genuinely deluxe pair of loudspeakers.  Many such speakers exist, but none of the affordable ones sound as good as the JBL bookshelf speakers I already own.  Those JBLs are the ideal size to fit in any room, but are simply too small to offer deep bass.  If you have ever been to a concert with a full orchestra (at least a hundred players) performing nineteenth- or early twentieth century repertoire, you know that the frequency range is as large as the dynamic range.  High violin pianissimi one instant make way the next for low brass and basses that shake your ribcage.  Obviously, nobody would listen to music at home at volume levels you find in the concert hall.  But my dream has been to own the sort of loudspeakers that can reproduce the full spectrum of sound the human ear can discern.  Those sort of speakers, alas, are hilariously unaffordable.

In a remarkably serendipitous way, I have become the proud owner of a pair of vintage AR-3a loudspeakers.  The 3a was the top-of-the-line speaker made by Acoustic Research of Cambridge, Massachusetts until the mid- to late 1970s.  In 1969, the year my speakers were built, the AR-3a cost over $500 a pair – a huge sum of money.  Expensive speakers like these were purchased primarily by studios, wealthy audiophiles, and professional musicians.  In fact, contemporary AR advertising demonstrates that their flagship loudspeaker was marketed largely to classical music fans.  In ad after ad, the 3a is shown in the listening rooms of the world’s most prominent conductors: Karl Böhm, Erich Leinsdorf, Seiji Ozawa, and Herbert von Karajan.    In a 1972 catalog, they make a point of mentioning that Dietrich Fischer-Dieskau–my favorite musician–listens to his own recordings on AR-3a loudspeakers!

How did I come to own such wonderful speakers?  I cannot say in this public forum, but it was pure luck.   The best way I can describe it is this: Imagine the physical thing that you want the most.  Then, imagine that somebody just gives it to you for nothing.  Then, imagine that they didn’t just give you that thing, but the very best version of that thing.  I could not be happier about it.

In another post, I’ll write about restoring these speakers, tell you what they look like, and how they sound.

Filed under: Music, Technology on February 13th, 2010 | 3 Comments »

Much ado is being made today about the simultaneous release of the newly-remastered Beatles catalog, and the interactive video game, Beatles Rock Band.  I am intrigued by the former, and ambivalent about the latter.

One one hand, Rock Band strikes me as the height of poserdom – another example of the artificial replacing the real in our society.  We don’t play tennis or go bowling anymore; we play Wii Fit.  We don’t play guitar; we play Guitar Hero.  John Lennon and Paul McCartney were introduced to one another on the afternoon of July 6, 1957.  Had the two merely played guitar-shaped pieces of plastic in their bedrooms instead of real guitars, popular music would be quite different today.  When the Beatles played the Ed Sullivan Show seven years later, an army of American boys were inspired to pick up their own guitars, start rock bands, and write the rock songs that defined an era.  What if today’s kids are picking up game controllers instead of real instruments?  Wither music?

On the other hand, a segment I heard on the radio last night raised a point I might have otherwise never considered.  A caller to On Point said that he treasures the quality time he has spent playing Rock Band with his children, and that it has helped him feel more connected with them.  They get to know his music, and he gets to know their music.  This got me thinking: what if the millions of parents who felt so upset by rock music in 1964 had instead been able to share the experience with their children?  After all, shaggy hair and suggestive hand-holding talk wasn’t really what bothered parents about the Beatles.  The Beatles were the physical embodiment of the growing divide separating the World War II generation from their kids.

The Beatles are popular enough, and certainly not at risk of being forgotten, even by kids today.  So I don’t think all this hoopla is about introducing a new generation to Lennon-McCartney.  I think, rather, that it might actually be about bonding.  Video games have divided parents and children for more than twenty years.  If Beatles Rock Band can bring them together, things really will have come full circle.

Filed under: Musings, Popular Music, Technology on September 9th, 2009 | No Comments »

I am taking an astronomy lab this semester.  It is supposed to be a one-hour-per-week class, but we meet for two hours every Thursday morning, and a couple hours at night several times throughout the semester.  I don’t know how the university considers that one hour, but they do.  So it was, then, that I felt a little annoyed to have to go out last night at 9:30.  I was looking forward to the looking, but distressed at the prospect of being at school until eleven o’clock, particularly when I had already spent my daytime hours in class and in the waiting room of Town Tire getting an oil change.

But my dismay quickly abated when I arrived at the observatory.  I had been there years before on a Friday night, when the facility is open to the public.  That visit marked the first time I had ever seen the rings of Saturn or the giant spot on Jupiter.  Last night was very clear, and the temperature quite pleasant.  There are only a dozen students in my class, and only eight of them showed up, so we all got plenty of time to use the telescopes.

Two eight inch reflectors were aimed at Albireo, a binary star in Cygnus.  It’s incredible to think that these two individual stars take a hundred thousand years to orbit one another.  We looked at two different objects in the 12 inch reflector.  The first, the Ring Nebula (M57), was a little disappointing.  In all the photos I have ever seen, the nebula appears to be vibrant and colorful, but in person it appears to be no more than a hazy ring.  Dr. Reyes, the director of the UF teaching observatories, told me that the the photos we see of the Ring Nebula are composites, and filter certain wavelengths of light to create beautiful images.  The second object we viewed with the 12 inch telescope was the open cluster M11.  It doesn’t look especially vibrant in photographs, and, to be honest, in person it is even more subtle, seeming at first to be just a hazy speck against the blackness of deep space.  But after staring for a minute or two, my eye began to perceive some of the brighter individual stars in the cluster.

Finally, before I left, I asked one of the graduate students to aim a telescope at Jupiter, since it was so bright in the southern sky.  Through the eight inch reflector (with a 26mm eyepiece), I could see the stripes in the planets atmosphere, and its four Galilean moons.  It was awesome.  It looked pretty much like this photo, but with the moons all to one side in a straight line.

I’m looking forward to our next night lab.

Filed under: School, Technology on September 9th, 2009 | No Comments »