Discussion in 'Speakers' started by BobHol, Jun 24, 2018.
i see a beautiful greyhound in the background there
Thank You That's our retired racer Turbo. My wife and I also foster ex-racing greyhounds. We'll be getting one this Saturday.
Didn't have a lot of time for the AR9's tonight. But I was able to pull out the Lower-mid drivers. The first surprise was the cylindrical enclosure behind the driver.
I'm not real surprised but I had figured I'd get a look at the crossover through that hole.
As I had mentioned the surrounds for this driver were different between the two speakers. On one of them the surround would crack at the slightest poke. The surround on the second driver had no cracks and easily survived repeated pokes Well I found out why. They are different model AR drivers.
The driver with the good surround was a 200027-0 (square magnet) I believe this is the correct driver for this speaker, and it must have been re-foamed at some time. The driver with the crumbly surround was a 1210045-08(round magnet). Did a little research and found that this driver was probably from a AR9-LSI or other newer AR system. Or maybe a factory replacement? A little disappointed to see that but glad that it wasn't some generic Radio Shack driver. Did a quick check on E-Bay and saw that 200027's may be a little rare. Outside of the magnet shape there doesn't seem to be much difference between them. I now don't think I'll worry about replacing the good surround and maybe I'll do the other driver myself. I'll use those drivers and someday I'll get another 200027.
Thank You Leesonic for the link. I see from reading yours and other threads that the enclosure behind the 8" lower-mids often comes loose and is made partially of cardboard. Mine seem to be very well attached. I saw a seam that suggested that the barrel of the "can" is cardboard, but it seemed to be very rigid. Adding some RTV sounds like a good idea and will be on my list. There was also a ring of polyfill stuffing in each can.
In general bonding silicone to cardboard is very week, unless it is plastic coated.
Well, A bead of a good wood glue will probably work better I suspect. Thanks.
Welcome o the AR 9 club. Here are my 200027-0 lower lower mid-ranges after new foam have been installed and before they went back in.
I have used the 8 in 037 woofers in both the square magnet and and Tonegen round magnet versions and I can't really tell the difference in sound. What may be more important is that the surrounds used have the same density and compliance. I used the Boston type filled fillet type on mine.
I read a lot of AR9 restoration threads before working on mine and Leesonic's was the most impressive to me.. If you notice the lower mid-ranges on his examples are slightly different than mine having the seam in the cone and the surrounds being attached to the back of the cones. AR made slight changes trough production of many of their models. Put plenty of power to those 9's and you will not be disappointed.
Took out a woofer to get a look at the crossover. Love the T-nuts and machine screws. I was amazed at the weight of that driver. Both crossovers were easily visible. I saw no signs that anyone had ever been there before. And no signs of leakage. Stuffing in the upper half of the box as expected. The crossovers matched the pictures that have been previously posted by others. I still plan on replacing the smaller caps. I'll replace the speaker gaskets. And I'll order a surround kit for the Lower-mids from R. Cobb. I'll eventually start looking harder at the walnut finish. But I wouldn't do much more than cleaning and polishing. The grills are in very good shape except for one of the woofer grills which has a couple of holes.
Great score! Have fun......
A few problems that are I plan on fixing.
I hadn't mentioned that I got a nice set of speaker cables with the speakers. Gemini Super Cable . They're at least 15 foot long. But the banana plugs have been butchered on one end of each cable. And one of the cables on one end has the color wrong. I had to include a picture of that.
Pulled all the woofers in order to get at the crossovers. Three of the four had the red wire connected to the terminal closest to the red dot on the label. The fourth had the black wire where the red one should have been.
Started replacing the caps one at a time for the upper crossover and I found a 4uf cap where the schematic showed a 8uF. This cap is connected in parallel to the upper mid speaker. The other box had an 8uF. The incorrect cap was black with red ends (Callin) just like all the other small caps. So I'm tempted to think that it left the factory that way. I did put an 8uF in its place. Before picture attached.
Ran into some minor problems with the one 8 inch lower mid that needed refoaming. Contacted one vendor about purchasing the correct foam. I followed what he said in the reply email, and ended up with surrounds for the 12 inch woofer. Sent an email to the vendor and his reply was that he was sorry to hear that I had ordered the wrong surrounds. He did say I could send them back. I then ordered the correct foams from somebody else. Before starting the refoam I read a lot of instructions on the internet. But still messed it up enough that I ended up taking the speaker to a local speaker shop. 1) I started off with too much glue 2) I didn't wait long enough for the glue to get "tacky". I was gluing the surround to the underside of the cone and it was a mess. So I removed the surround. I had not cut into the dust cap and the cone was undamaged so it should still be a routine re-foam for somebody who knows what he's doing.
That's where I sit now. Taking my time with the re-cap. My soldering skills are better than my gluing skills. I should have the Lower-mid back in a day or two.
I ordered some foam for new speaker gaskets. These type of problems are all part of the vintage speaker experience and aren't all that stressful for me.
Good day all.
Weird issue there with the oddball cap and the one wire. Let's see what others have to say about those things.
Maybe it was Monday when they assembled that one. Yikes.
I thought that also. But only for the wrong cap. There was evidence that one of the woofers had been replaced. There was a receipt taped to the magnet.
So I suspect some one had mis-wired the woofer after these left the factory.
I took the mid to my local speaker repair shop. The driver had sat in my car the whole day so it was warm. A tech used his magic fingers and poped out the dent, Just a small depression left.
So basically 3 weeks after the AR9's show up at my house they are now fully functioning and in place to reproduce music. I had one lower mid speaker re-foamed. Speaker Workshop in Fort Wayne does a fine job at that. I replaced all caps except for the two biggest one's (370uf &25000uf). I left the crossover boards in the box. So the connections and soldering wasn't always pretty. The only hassle was soldering to a coil wire that had a coating on it. The foam gasket material that is sold by Parts Express is so much easier than using putty. Made a wild ass guess as to how far apart to locate the speakers along the back wall. Hooked them up to my Adcom GFA-6000. Held my breath and everything worked! Only had time for a brief test. A few Bonny Raitt songs. A few songs by Little Feat from my favorite studio album of theres. And last the 1970 Hot Tuna live album. I'll have a longer session tonight with a local jazz show on a Fort Wayne NPR station. So I'll have a better evaluation after my ears and the caps burn in. Sounds like the Adcom will be fine until the Hafler DH-500 is up and running.
Hot Tuna! I know someone who knows some of those guys. Great rock & roll.
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